*Contents:* 0:00 - Intro 0:53 - Background 3:09 - Study Procedure 5:30 - Study Results 6:09 - Acceleration Effects 7:53 - Speed Effects 8:59 - Wrap Up *Specific Videos Mentioned:* Top 10 Pool and Billiard Myths Busted and Debunked: th-cam.com/video/cdlQuEQcpRs/w-d-xo.html Cue Tip Contact Myth-Busting Truths in Super Slow Motion: th-cam.com/video/HwayvH9z1hk/w-d-xo.html STROKE TIMING … A Complete MythBusting Study of Stroke Acceleration Effects: th-cam.com/video/0m6g7lBh17c/w-d-xo.html GOOD TIMING in Pool … What Does It Mean?: th-cam.com/video/XijiqaQyaGk/w-d-xo.html CUE BALL CONTROL ... Everything You Need to Know: th-cam.com/video/fPQEBxbByD4/w-d-xo.html *Supporting Resources:* - stroke “best practices:” billiards.colostate.edu/faq/stroke/technique/ - draw shot technique advice: billiards.colostate.edu/faq/draw/advice-and-drills/ - stroke acceleration resource page: billiards.colostate.edu/faq/stroke/acceleration/ - stroke timing resource page: billiards.colostate.edu/faq/stroke/good-timing/ - cue tip contact time resource page: billiards.colostate.edu/faq/cue-tip/contact-time/ - cue tip hardness effects resource page: billiards.colostate.edu/faq/cue-tip/hardness/ - pool myths resource page: billiards.colostate.edu/myths/ - cue ball control tutorial: billiards.colostate.edu/tutorial/cue-ball-control/ *Subscribe to Dr. Dave's TH-cam Channel:* th-cam.com/users/DrDaveBilliards
I always find it fascinating how, despite numerous years of study to obtain your doctorate, and a number of decades teaching and research, you still have the curiosity to continue learning new things, and the teacher in you never dies (to all of our benefit, I might add). Always have and will love your resources, Dr. Dave.
I'm glad you like my stuff. That's one reason why I love this wonderful game so much ... there is always something new to learn and apply. And it is challenging and fun to play well!
Dr Dave. I personally cannot even find the words to appreciate this work that you put in. I wish someday your videos help me and others to jumpstart careers in billiards.
@DrDaveBilliards education and effort does not a doctor make. You need no education to be or be called a doctor. I'm always a bit skeptical when I see these DD videos and the math isn't presented/purported accurately.
@@cardguys FYI, I am a "doctor." I have a PhD in mechanical engineering. For more info, see: billiards.colostate.edu/dr-dave/ www.engr.colostate.edu/~dga/ I also have a "Doctorate of Pool" from the BU: billiarduniversity.org/testing/alumni/ So there. :)
@@cardguys Nothing to say to Dr.Dave now? Everyone who watches his videos knows he is an actual doctor, just listen to the way he articulates himself in the videos.
I'm a big fan and you obviously debunk those myths. I do believe I have an important correction/addition: Cue stick angle of attack: you state repeatedly that the only thing that really matters is tip contact point and speed. But it is actually the full velocity vector (taking into account angle of thrust) that must be considered, not just the scalar "speed". This is obvious when you consider "jacked up" shots (to avoid double-cue-hit or when jacked up attempting draw over a ball or the rail): draw action is created even with a contact point that is above-center when considering a horizontal perspective - or even when considering the marks on the training cue-ball that you have. The affects should be material even for non-jacked up shots but where you vary how "unlevel" the cue stick is at point of impact
I probably should have mentioned cue elevation effects and that we were using a near-level cue on every shot. FYI, I cover draw shot cue elevation effects in detail via the info, videos, and links here: billiards.colostate.edu/faq/draw/cue-elevation/
My takeaways from this that aren't discussed in the video, correct me if I'm wrong with any of these, Dr. Dave!: Essentially, what this means in terms of strokes is that the "follow through" advice often given is not actually important in terms of implementing backspin on the cue ball but rather just a best practice to avoid decelerating the stroke too much before impact (i.e. hesitating to hit the CB as fast as you would like because you psychologically start the pull-back action earlier than when you would want to), given a certain goal of draw speed. This makes sense because sometimes you're forced to pull back instead of being able to follow through on shots where the cue ball and object ball are nearly frozen to avoid a double-hit foul, but you can still impart strong backspin due to the shorter travel time of the cue ball to the object ball and nothing significant changes (in practice) with tip contact time. This also further supports the idea that tip hardness is MOSTLY insignificant when it comes to spins and draw shots in particular. Or a better way to put it, there's no significant difference between tip hardness that you can't adjust for through practice with the same cue and tip, and will most likely only notice when you suddenly switch to a different tip type for the same exact shot.
That all sounds good. For more info on these topics, see: billiards.colostate.edu/faq/stroke/follow-through/ billiards.colostate.edu/faq/stroke/acceleration/ billiards.colostate.edu/faq/cue-tip/hardness/
Anybody that plays pool and wants to get serious about it has to love Daves detailed videos. Theres so much false or inaccurate info out there and just because your a great player doesn't mean your a good coach thanks dave
Years ago I formulated what I call a Fundamental Theorem of Billiards (FTB): Provided the playing equipment is constant, the result of a shot is fully determined by: (1) speed of the cue when it hits the cue ball, (2) direction of the cue when it hits the cue ball, (3) point on the cue ball that is hit by the cue. FTB goes without proof, so it is more an axiom, but I liked the name. Some of the points can be merged using the concept of vector, but I find the above formulation most useful. For me FTB is basically a foundation that my game is built on. I used to think that FTB is a model/approximation that ignores some aspects of reality (e.g. timing), but is practical due to its simplicity. After watching this video I think that FTB is closer to reality than I thought before.
Thank you so much for all the effort you put into the videos. This is a model of how videos should be produced based on feedback. This puts to rest tons of anecdotal advice which is often incorrect (understandably so, due to lack of rigorous investigation, but incorrect nevertheless). This also furthers our understanding of the game - thank you so much!
Thank you so much for all the work. I can see why people think that your tip is on the cue ball longer on a draw Shot with long follow through and acceleration. But I believe your test results 100%. Love your videos. I wish I had all this information when I was learning to play in the mid-60s. Back then everything was hush-hush and when you ask a good player for a pointer or how he hit a shot he would say you hit a million balls and you'll know how! Or something to that effect. Different times! Anyway thanks again thanks again for all your videos and hard work. Peace
Dr. Dave - you're a true hero! Your testing methods and explanation styles are truly peerless in this sport. It's fascinating to see how much of staple technique advice is really only a means to getting a person's arm to deliver very simple outcomes in terms of cue motion. I'm curious if you've ever tried similar experiments but with a beginner with poor fundamentals? Both you and Pubo clearly are extremely accomplished players with extraordinarily consistent shot strokes, and I suppose you would struggle to play a badly-timed shot if you tried. I would find it interesting and valuable to see which measurable factor(s) most often caused a bad draw shot for a player - was it contact point, or cue speed, or perhaps even another variable (perhaps you've ruled that out but would observing bad techniques help reinforce this?). I imagine the testing process would be a lot messier though so that may be offputting.
I already know from many years of teaching experience and observing countless league players what causes bad draw shot results. They are all listed and demonstrated in the videos here: billiards.colostate.edu/faq/draw/advice-and-drills/ Enjoy! PS: I am very good at demonstrating bad stuff. I had lots of experience in the past.
Science will always prevail. As I have said before, "I quit arguing tip hardness, contact time, and which will generate more cue ball spin years ago." It is because of Robert Byrne's teaching videos (yes VHS, I'm old) and Bob Jewett's slow motion studies, I believe it was called the Jacksonville Experiment or Project, I have the PDF files saved somewhere from years of digging back in the late 90's on this subject. I am rambling but have always used a hard tip from what Bob Byrne's taught. Great video, as always.
I also prefer a harder tip for the reasons here: billiards.colostate.edu/faq/cue-tip/hardness/ FYI, all the Jacksonville Project info can be found here: billiards.colostate.edu/faq/video/Jacksonville-Project/
@DrDaveBilliards always great info on your colostate page. Thank you for all of the information you provide that is backed up by applied science/physics. Great stuff.
Dr Dave. Thank you for your hard work. I've enjoyed your knowledge for many years! My question is this: F1 race cars used to use super soft qualifying tires that wore out in one lap. Why don't we use soft rubber tips on our sticks? Seems like an optimum compound could be created for this purpose. Second question: How does the chalk build up on filthy bar boxes effect ball action on draw and throw? Thank you once again!
First: A really soft and bouncy tip would extend the tip contact time too long, creating far too much CB deflection. See: billiards.colostate.edu/faq/squirt/cause/ Second: A dirty cloth could contribute to an increased change for cling/skid/kick (excessive throw), especially if the balls are dirty with body oil that might pick up the chalk dust. A dirtier cloth definitely makes it tougher to draw the ball. See: billiards.colostate.edu/faq/throw/cling/ billiards.colostate.edu/faq/table/cloth-effects/
The important forces are the extremely large impulsive forces between the tip and CB that accelerate the CB. The effect of the relatively miniscule forces being applied by the grip hand on the cue are unimportant to the motion of the CB. For more info, see: billiards.colostate.edu/faq/grip/light-vs-tight/ billiards.colostate.edu/faq/stroke/acceleration/ billiards.colostate.edu/faq/cue-tip/contact-time/
Dr. Dave. I think this is wonderful and proves your point experimentally. Well done! And thanks for your responsiveness. I think it would be great if you use your partner and his setup to examine cue stick angle (up to several degrees anyways) to determine its effects on draw as well as on force follow (where some insist there's a huge difference from angle and finishing UP is critical. At about 2:50, you show a chart of cue speed vs time. Is this chart real? Does it really represent the results of different strokes and that there's a particular type that uniquely results in that higher speed needed for more draw? If so, I think that deserves and I would appreciate some followup to explain it, including what's necessary to achieve that. Hitting low on the cue ball has been beaten to death, but there's little information about this acceleration technique. Is it impacted by bridge length or backstroke length, wrist action, muscle fiber types or what? How would you practice it and recognize progress (I mean as a dry practice or just with a cue ball), working up to doing actual draw shots?
I honestly don't feel a need (nor do I have the interest or motivation) to do additional tests related to this topic. I have already beat it to death (per all the past videos linked in the video description). Also, the science on most of these topics is already clear. See: billiards.colostate.edu/faq/draw/cue-elevation/ billiards.colostate.edu/faq/draw/physics-advice/ billiards.colostate.edu/faq/stroke/acceleration/ billiards.colostate.edu/faq/cue/weight/ billiards.colostate.edu/faq/stroke/follow-through/
First I want to say thanks for all your hard work, you provide a lot of good information! However: Striking as low as possible, with elevation can provide more draw in certain circumstances. The elevated cue will cause the cue ball to skip across the table. Less contact time with the table, less backspin loss. Sure it’s difficult and adds another degree of complexity which makes the shot more missable, but doesn’t change the fact that what you’re stating is only applicable to your testing conditions. (Your table, felt, temp/humidity)
You're welcome. Cue elevation can narrow the draw angle per the info and demos here: billiards.colostate.edu/faq/draw/quick/ But cue elevation does not help create more draw for the reasons here: billiards.colostate.edu/faq/draw/cue-elevation/ The CB loses more backspin on the first bounce than is saves by being airborne. And you are correct. Cloth conditions play a huge roll: billiards.colostate.edu/faq/table/cloth-effects/
This may or may not apply here but Fedor Gorst talks about "pushing" the cb as opposed to hitting it. I would imagine the contact time would not change. Might be an interesting collaboration on the subject.
thanks for the great effort to demo this for us! Will the weight of the cue matter here? I assume heavy cue with the same speed will translate into more energy， right？
You have the soul of a scientist. Although insufficient data, it looks a bit like a step down transition point in the 395 to 415 cm/s speed range? If a real effect, maybe a threshold in tip compression or shaft flex?
More data (and more careful measurement of tip contact height (maybe by observing chalk marks on the CB) might have helped. Also, the effect you are seeing might be somewhat exaggerated by the small scale range on the vertical axis.
Great work, Dr Dave. However, I am not sure if your conclusion to the shot at 7:12 is correct as the two cues are travelling at basically identical speeds if you compare them frame by frame. I was expecting the "accelerating" cue catching up with the "decelerating" one instead.
@@DrDaveBilliards @DrDaveBilliards You are right that for example, in shot No. 8 with a=-1155cm/S^2 and v=408cm/S, the velocity should be at around 409cm/S just a millisecond before the impact. However, with the resolution of roughly only 30 pixels/ms from your table at 4:08, I wonder what are the precisions of your velocity and acceleration measurements?
@@laitaumou1043 The two shots have impact speeds 408cm/s and 412 cm/s. So they only differ by 4cm/s. The clip shows the last 105 frames until impact. Since the footage was recorded at 19783 fps, that corresponds to 0.005s time elapsed. During this time interval, two cues would have traveled distances only 0.02cm = 0.2mm different, which is about width of 4 human hair.
@@laitaumou1043 I'm not quite sure what you mean by the precision of the measurement. If you mean sampling rate, the velocity and accelerations are all calculated from the position data of the cue, which is tracked frame by frame, so 60 data points/second. Of course the data are then turned into smooth polynomials for ease of differentiation. If you mean the accuracy of the tracking, I don't really have a good way to quantify this, since I used python packages and after effect, and I don't know how they actually implemented the algorithms, therefore neither its accuracy.
Thank you Dr Dave! I've been wondering the whole video how would changing the cue angle (elevation) would affect the draw shot / contact time, with the extreme example being a masse shot but for example a draw shot from the rail or over a ball, what would make a big difference in that case?
For information and demonstrations of what cue elevation does to draw shots, see the resource here: billiards.colostate.edu/faq/draw/cue-elevation/ and here: billiards.colostate.edu/faq/draw/quick/ Highly elevated masse shots are a different story: billiards.colostate.edu/faq/masse/
Nice.. How do different cue weights change this? Do we have to talk about "impulse" instead of "speed"? The weight of the cue influences how a player is able to accelerate the stick (the heavier the cue, the lower the max. speed). But a heavy cue does not have to be as fast as a lighter cue to impart the same impulse to the cue ball. Hypothesis: If you are srtong or very skilled, you might choose a lighter cue and generate the impulse with your muscels. If you are weaker or unskilled use a heavier cue and let the mass do the work.
Thank you for the video. I was wondering; if one wanted to maximize draw/speed ratio with cut shots (quarter-ball hit or more), would jacking up help in that case? I would think that in the extreme case, the cue moving directly downward towards the table while hitting CB at the six o'clock mark, would maximize this ratio. On the other hand, the CB starts to get pressed against the table somewhat when you jack up the cue (and maybe even little bit of jumping may occur?). The problem with draw and thinner cuts of course is that CB retains more of its own speed after contact with OB, and the higher "residual" speed causes it to travel along the tangent line further before the draw can take effect.
Cue elevation reduces backspin but it can narrow the draw angle. See: billiards.colostate.edu/faq/draw/quick/ billiards.colostate.edu/faq/draw/cue-elevation/
Have you ever used or considered using a slight funnel shape tip? Do you think the additional contract area, would allow for more controlled spins without misscuing?
So just hit it faster. Check! Can you study why some players hit the cue ball quite slowly but still get great cue ball movement? Like, say Fedor Gorst style for example?
Low and fast is all it takes. Draw looks effortless for some players because they use a longer stroke length and accelerate very smoothly. When done well, it takes less effort, but the cue speed at contact is the same. For advice on how to do it, see the videos and info here: billiards.colostate.edu/faq/draw/advice-and-drills/
Do you have the result videos on shot 24 vs shot 25 and 36 vs 261? same position , same speed , different contact time ..........although he didn't change cue tip hardness. Maybe more clear to change the hardness and cross compare again.
I could have shown more shot comparisons, but I didn’t want the video to get too long. Regardless, the graphs showing the results for shots clearly show the important trends. FYI, cue tip hardness effects are covered in detail here: billiards.colostate.edu/faq/cue-tip/hardness/
Does a smaller diameter tip allow for a miscue limit hit further away from CB center, and would that produce more backspin with any given cue speed? What effect if any, does the diameter of the tip have on the maximum amount of spin that can be generated, and is there an optimal diameter assuming that cue speed remains the same? Do low deflection shafts perform better or worse than old school shafts with heavy ferrules when it comes to maximizing backspin?
Answers to these and related questions can be found here: billiards.colostate.edu/faq/cue-tip/size-and-shape/ billiards.colostate.edu/faq/cue/low-squirt/#spin
@@DrDaveBilliards Excellent studies, but there has been no examination of the effects of an applied downward acceleration of the grip hand just prior to cue tip contact. This upward angle cue tip acceleration opposes the cue tip deflection that will happen following impact, and is the pro nuance for obtaining maximum backspin. You are doing this acceleration yourself as can be evidenced by the raised to level tip position on shot completion in the videos of your maximum draw shots. I also noticed (in this slow motion video) that the radius profile of the tip was starting to flatten somewhat at the upper shoulder where repeated contact was occurring, and this may have contributed to more scattered and inconsistent results concerning the precise offset of that shot.
What about grip tightness? I still think a tight grip at contact point give the cue ball more speed & more draw action (because it adds mass to the cue). Maybe you could debunk that, here is a suggestion for testing: - 2 shots, with same cue speed & cue acceleration at contact point, same contact point; the only difference is, one with a lose grip and one with a tight grip (at contact point). Then we measure the speed of the cue ball, the spin (how many round per sec), and the draw action (how far the cue ball goes back). The result will settle this problem once and for all.
Some people just sort of have "it". Alex Higgins looked like he was having a seizure while he was down on a shot and he was world snooker champion twice.
@@myyoutubename4067 Any technique can be mastered with enough practice. “Best practices” techniques are easier and faster to learn and master for most people.
Its true that acceleration doesnt mean much due to brief contact time, but contacting the cueball when your cue is accelerating mostly translates to a higher cue speed upon contact. Teaching the acceleration portion while teaching draw is still relevant in my opinion, especially in imparting a proper stroke or getting more reaction. I found it effective in teaching draw by slightly reducing the pull back and increasing the follow through so as to contact the cue ball while the cue is accelerating to attain a higher speed at time of contact. I dont want to be teaching the "unimportant stuff" or "wrong stuff", but i cannot find a more effective way in teaching draw without using the word "acceleration".
As I pointed out in the video, smoothly accelerating stroke is critical to accuracy, consistency, and speed control per all the info and advice here: billiards.colostate.edu/faq/stroke/technique/ But most good players reach maximum speed (with zero acceleration) just before contact. Per the info and study link here: billiards.colostate.edu/faq/stroke/acceleration/ If you are still accelerating at impact, it means you didn’t accelerate and generate speed early enough. Many players actually decelerate just before contact due to poor timing: billiards.colostate.edu/faq/stroke/good-timing/
In my mind, the FEELING of acceleration at impact is extremely important to a good stroke. As Dave said, it is the best way to be accurate, and, importantly, consistent. With the use of these slow motion videos, we can understand that what we’re feeling isn’t what is actually giving us the results, but if this feeling is the most effective way to be accurate and consistent, then by all means, use it.
That’s surprising - good to know. I’m just curious your view on it - obviously for most physics problems you just need the force vector of impact to calculate a trajectory since all the information is encoded and the lead up doesn’t matter. I guess the contact time makes no difference because of the time frame of which you’re extending it? Makes it negligible?
With collisions, the contact time is not really important. What is important is the momentum of the cue. I try to explain it a little more here, along with other useful supporting links: billiards.colostate.edu/faq/cue-tip/contact-time/ The efficiency of the hit (which is mostly related to tip hardness) is also a factor. See: billiards.colostate.edu/faq/cue-tip/hardness/
Hey Dave... does the roundness of the tip determine the lengths of tip contact? I would think the more round the tip the more surface of the tip is contacting resulting in more spin.
No. FYI, all tip shape and size effects are covered in detail here: billiards.colostate.edu/faq/cue-tip/size-and-shape/ Now, tip hardness does affect tip contact time. See the videos and info here: billiards.colostate.edu/faq/cue-tip/hardness/
@DrDaveBilliards TLDR; Is quality shaft important for the success of full length table power draw shots? Back story: I play exclusively in bars and pool halls on 9 feet tables. Often times the cloth is smooth and fresh. I use the basic cue stick available at their disposal as I yet have to get one of my own. I play 1-2 times weeekly for the past 2 years, so I have a solid amount of experience. I am wondering why when attempting power draw shot across full table length I either scoop the cue ball or the ball loses most of it's spin and the ball returns only about third of the table. I can rarely get the cue ball to return half table length when practicing draw shot and in actual game the success rate is even lower. Is it reasonable to blame the bar cue sticks which aren't as stiff supposed to a professional cue stick? Cue tips are hard and round on all of them so i think I can rule this out. It might very well be lack of speed as I'm not in a great physical form, but that's not what I would like to be blamed for even tho I'm sure that's also part of the problem.. 😅
The cue is not so important, assuming the tip holds chalk (and is chalked), and assuming the shaft and ferrule are not cracked. Getting good and consistent draw is all about good technique. If you want help, see the videos and info here: billiards.colostate.edu/faq/draw/advice-and-drills/ The cloth type and condition are also important: billiards.colostate.edu/faq/table/cloth-effects/
Over long distance, you can also jack up slightly and not hit as low to get the ball to jump slightly so the back spin doesn't wear off as fast. The cue ball also has more speed compared to cue speed because you are hitting closer to center so it gets to the object ball faster and again has less time to lose back spin. This effect also helps even if you don't jump the cue ball. The hard part is picking the right spot on the cue ball to balance all effects to get maximum draw especially when you take into consideration distance to the object ball and cloth conditions (don't even start on barbox cueballs).
Jacking up the cue more than is necessary to clear the rails does not help draw distance. For the reasons why, see: billiards.colostate.edu/faq/draw/cue-elevation/
It reall does. You are focused on increasing spin. Jacking up does not increase spin, it just causes the cue ball to stay airborne so it doesn't lose spin due to friction. Try it. If you can get the cue ball to reach the object ball in 2 or fewer bounds, it will dramatically increase effective draw if the cue ball is more than 5 diamonds away from the object ball and especially if you have slow cloth.
@@Gotwired I have tried it. I can get more draw with the cue as level as possible (on any cloth). I have also done a careful and thorough physics-based analysis. For the reasons why an elevated cue does not help (unless the cue elevation helps you generate a more powerful stroke for some reason), see: billiards.colostate.edu/faq/draw/cue-elevation/
I think these myths still get spread because they change how people think of their cue delivery, like they hear "accelerating with good timing" and maybe slow down the backswing (resulting in less unwanted steering) and a faster forward swing (resulting in greater draw distance). Then the figure "well what I was told is working, and it sounds scientific, so the info must be accurate". Like the old adage "it's hard to argue wth success". That, combined with people's natural reluctance to ever back down when arguing on the internet, means the debate will probably go on forever.
Hi Dr Dave One thing that I have wondered about is the effect of the weight of the cue for different players. It is probably highly individual. A light cue would probably be faster but that would give less momentum and as such give less draw or other effect at some point. I wonder if there is some way of finding out the optimal weight of a cue for different players in case you don't have a speed camera. Could you please give your wives on this subject.
I'm curious what the effect of cue tip deflection has on the quality of draw and follow shots. Would it be possible to build a rig that imparts 0 deflection upon striking the cue ball? Maybe a roller or plastic "sled" that attaches to the tip. If the tip doesn't deflect at all upon impact, would it force the ball to hop? I think this information. Would be useful in determining the right type and size of shaft to play.
With an off-center hit, the tip always flexes away from the CB (most after the hit). If the shaft were stiff and heavy enough to prevent this, there would be a huge amount of CB deflection (AKA squirt). For more info, see: billiards.colostate.edu/faq/squirt/cause/
I also experiment a lot with pool billiards. However, I don't put in that much effort into measuring. I work with very different ferrule diameters. (usually between 12.9 and 10.5 mm) What becomes clear here is the contact point of the top edge of the tip. This seems - also based on the measurement - to be significant for the draw result. With a thicker tip diameter, the bottom edge is very close to the base plate at the point of contact, while when using the thin tip size the rule clearly applies that you have to aim for a tip width above the table width. As far as the hardness of the leather is concerned (that wasn't the topic in the video), I always notice that long draw shots are subjectively easier with harder tips. Energy transfer certainly plays a certain role, which results in acceleration. In my opinion, the grip of the leather surface should also be examined in more detail (roughness in interaction with chalk characteristics), although this property is more relevant for short distances and applying side spin.
I have a request. A little backstory. Some time back you did a video regarding spin and correlation to tip hardness. IE phenolic vs leather you probably remember. I was out shooting a week or so ago and had a guy grumbling about his tip being too hard to get spin on the same token, I could clearly see, he wasn't getting the spin his cue path should have generated. I took a look at his tip and it was near flat. He was using less than 1/16 of the available surface and expecting it to grip. I tried to explain to him the shape of the tip has more impact on spin than the hardness, but...well, naturally he "knew better". Could you please make a video comparing different tip shapes and their effect on spin? This could even possibly down the road lead into something on the importance of tip shape retention. But I digress, where was I. Oh yeah, but such a comparison video would make explaining such things easier, especially from a reliable source that you are.
One thing I've always wondered is if the particular dome radius the tip is shaped to has a significant impact on how far you can hit the cue ball below the middle at iso speed without miscueing.
@@DrDaveBilliards Thank you for taking the time to reply, interesting read. It always strikes me just how many tiny effects are involved in producing the final motion, even if the general physics involved seem to be obvious enough at first. I guess that is mostly a result of using perfectly hard and smooth model materials in our heads when we make calculations, while cloths, tips, cues and balls all have their own material properties that make them anything but perfect model materials. The effects may be small, but they can add up on certain types of shots. I didn't think I'd ever get any answers to these lingering questions I've always had playing various cue sports over the past twenty years, but thanks to yourself and others, the research is finally being done.
I wonder if a super hard tip might slip more with lower contact points? Less tip deformation reduces contact area which might result in less frictional resistance?
@@nitrostudy9049as long as the tip is holding chalk properly then it shouldn't matter. Point of contact is already extremely small so the only difference between tips is that the soft one may hold chalk slightly better than the hard one, but if you're thorough at applying chalk then the tip shouldn't slip.
For those interested in these topics, see the videos, info, and links here: billiards.colostate.edu/faq/cue-tip/hardness/ billiards.colostate.edu/faq/cue-tip/efficiency/ billiards.colostate.edu/faq/chalk/comparison/
How much of an effect does the width of the tip have? I would assume with a thinner tip one could strike lower on the cue ball and ergo generate more draw
This is true only if you use outrageously big tip. If your tips are 10mm vs 30mm. Then yes because you cannot hit the miscue limit using a 30mm tip. But for the common tip sizes ranging from 9-14mm, you can hit the miscue limit regardless of your tip sizes. If you use a 14 mm you need to lower the tip more than with a 9mm just because of the geometry. But as long as you hit the same place on the ball with the same speed, the results should be almost identical (considering your two cues and tips might be a little different in weights)
I think an interesting case study in draw action would be Jayson Shaw. He has a fairly compact stroke, and doesnt hit the ball exceptionally low, yet can generate a tremendous amount of draw. I notice on his power draw shots he gets a bit wristier and looser in his hand, which increases the speed. He also has a very well timed snap which produces a lot of power, similar to kinetic chain linking in a golf swing. I suppose there is a sliding scale of speed and tip position. He must generate enough speed to compensate for the tip being higher than, say, Jeff de Luna.
A good stroke combined with some wrist action is often used to get a very very high cue speed with easy. I often use more wrist when playing larger draws.
Thank you Dr Dave for yet another excellent video. So technically it turns out a follow through is not really needed after all. Also, it would be interesting to see a similar experiment but done with two different cues, say a very cheap one and one with a carbon fiber shaft. Ideally both having the same tip and similar weight, too. Just to see if the draw action changes if the shot is played with exactly the same speed and tip contact point.
A follow through is not really needed, but it is almost guaranteed to happen with a good stroke. See: billiards.colostate.edu/faq/stroke/follow-through/
What does it mean when the balls don't bounce off the cushion perpendicular to the angle they approach? My rails are in good condition but seem to eliminate zig zag causing the ball to not travel down the table but to bounce back and forth between the opposite rails or even come backwards. My guess is that my 2" balls are too small for my cushion nose. According to my math, if I use 2 1/4 inch balls, my cushion nose height (28mm) will just be above the centre height of the ball.
That's Dr. Dave and Pubo Huang for working on this myth busting. I've long been convinced that those guys with "super draw" are simply hitting the cue ball nearer the miscue point that those who seem less able to get significant draw. Nobody likes to look like an idiot by miscuing, so they don't strike as low as they could. What this means to me is that one SHOULD be miscuing on a regular basis in practice, in order to familiarize oneself with the miscue point, and learn how to come very close and still not miscue.
Thanks! Actually, it is better to hit slightly above miscue limit and with slightly more speed. This way you don't risk too much miscuing and can get as much draw too!
They are hitting the ball low, but they are mostly generating more cue speed (with smooth acceleration over a long stroke length). Concerning Pubo's point, see the videos and info here: billiards.colostate.edu/faq/draw/power/
@@DrDaveBilliards Virtually anyone can hit a ball hard (and "hard" can only mean with more speed). Not everyone is good at hitting maximally low without miscuing. Virtually everyone knows that it's necessary to hit the ball hard to get a lot of draw -- yet not everyone GETS that draw. It can only be because they don't hit the ball maximally low. It takes NO CONTROL to hit a ball hard, it takes a lot of precision to hit a ball very near but not AT the point of miscuing.
Dr. Dave do you think you could make a video either explaining the benefits of using a bigger shaft say 12.5 compared to say a 11.5 or smaller. I always hear that a large shaft is more forgiving but is it really and what is the advantage of each. That might be interesting. If you have already address this I must have missed it. Thanks.
hello dr dave this has nothing to do with the video but the table that i play on at my local pool hall has a weird problem one of the cushions deflects the ball with more speed so if i roll the cue ball into it it comes back with more speed any ideas how this could happen?
The height of the cushion nose is probably a little low, or maybe the other rails are not as solid. See: billiards.colostate.edu/faq/table/cushion-nose-height/
Rail nose height can cause this, most commonly when the rails are reclothed. Another possibility is a rubber was changed on this rail, and it performs differently than the others. This happens on commercial tables generally, where sometimes only the "bad" rubber gets replaced, as opposed to a full set. Thanks for the continued great content Dave - definitely a game changer for teaching and explaining draw principles 👍
my drunk ass didnt understand a thing but still paid full atention to this vdeo. great as aways ! please doo a video on diferent rules, like russian brasilians and snooker !
Maybe you can watch it again and absorb more when you are sober. :) I don’t play or honestly have much interest in those other games, so I’m probably not the best person for the job. Good idea though.
I recently started going to a place near me. Got a new cue also. But all the sudden I CANNOT draw for crap anymore. Where I'd expect a 2-3 foot draw, I get a stop shot. Idk what's going on. Not sure if my tip is messed up or the tables are.
I'm not saying that at all. What happens with cue acceleration or the grip hand during the incredibly brief moment of cue tip contact has nothing to do with the action of the shot, but having good fundamentals (including not tightening the grip) has everything to do with delivering the cue with the desired speed and tip contact point with accuracy and consistency. See the videos and info here: billiards.colostate.edu/faq/stroke/technique/ billiards.colostate.edu/faq/grip/technique/ billiards.colostate.edu/faq/stroke/good-timing/ billiards.colostate.edu/faq/stroke/acceleration/ Enjoy!
I completely understand and agree with the physics involved, but in order to be consistent, a repeatable stroke is an absolute must, and good mechanics promote that. Otherwise, what difference would solid mechanics make? And judging by all the greatest players having excellent fundamentals, I'd venture to say that it does matter.
I’d tried to make this point at the beginning of the video. Good fundamentals, timing, and acceleration during the forward stroke into the ball are critical for accuracy and consistency, but what is happening at the instant of contact is unimportant. The videos and info here cover all the important stuff concerning a good stroke: billiards.colostate.edu/faq/stroke/technique/ billiards.colostate.edu/faq/stroke/good-timing/ billiards.colostate.edu/faq/stroke/acceleration/
@@DrDaveBilliards It's a great video, as are most of yours. My background is in engineering and I think like you. My friends have argued with me multiple times about the chalk and tip hardness video results. A similar video about weight of a break cue, and I think that'll round out the arguments, lol. I keep trying to tell them lightening the cue can get you more power (assuming you can generate enough velocity). Some just don't understand the concept of mass x velocity squared. Keep up the good work!! And thank you.
@@joncue0304 Check out and have your friends check out this page that covers cue weight questions in great detail: billiards.colostate.edu/faq/cue/weight/ That should settle the argument.
I really need help . Sometimes i cant hit a slow straight draw shot . Im a big guy (1.95m) and i feel like im either off balance or it feels like i throw a spear into the cueball because i hold the butt of the cue with only the index finger. Seems like i need a longer cue . I think im off balance and when i try a long enough bridge my pendulum stroke has bad technique
you need to work on your shot routine, 100%. You need to be getting down on the ball the same way and into stable, good position for every single shot, regardless of shot type. If you are struggling to get consistent draw, you are not hitting low enough on the cue ball with enough power, it's really as simple as that. You should never, ever be holding the butt of the cue with 1 finger, that is totally pointless and harmful to your game. The length of your cue does not matter in the slightest if your fundamentals are all wrong, put the cue length out of your head entirely, whatever you're using now is probably fine
This can result in more backspin if the downward motion creates a lower tip contact point, but the swiping motion is not helpful. See the videos and info here: billiards.colostate.edu/faq/stroke/swoop-swipe/
Some assumptions need to be cleared up, F=MA. So where the force is imparted and how that force is imparted is all that matters. So bridge hand and blah blah blah do not matter, but the speed and mass of the cue stick and location on the cue ball are ALL that matter.
Dr. Dave, you're not a stats guy. Those 5:40 and 6:00 data points do not actually speak to a linear regression. Although the regression can be calculated, if there isn't an appreciable trend, the regression means diddly.
Dave was never a real scientist, so don't bother. You'll just hurt his feelings, and never get a straight answer. He aims to swerve (around hard questions). He's a glorified H.S. physics teacher...and a wannabe science popularizer.
@loum5254 See: billiards.colostate.edu/dr-dave/ www.engr.colostate.edu/~dga/ You are correct. I was never a "scientist." But I have a PhD and was a university mechanical engineering professor for 30 years.
In my humble opinion, all contact time is 1/1000 of a second. Do the measurements at 1/10,000 and the ones at 1/100,000 of a second longer that 1/1000 of a second mean anything? No, I don't even think you can see a difference of 1/500 contact time let alone between 1/10,000 or 1/100,000 of a second. It's like computer memory. "I'm upgrading 2400 MHz to 3000 MHz because I want faster speed." Will you see anything "faster" happen on your computer because you increased your speed by 600 MILLION cycles per second when you already have 2,400 MILLION cycles per second? No. So anything more that 1/1000 second is measurable, but not a factor.
There are changes in tip contact time with tip hardness and shot speed; but, as you point out, these differences are unimportant per the info and videos here: billiards.colostate.edu/faq/cue-tip/contact-time/
I think it is instead a "relaxed wrist along for the ride" motion. See: billiards.colostate.edu/faq/stroke/wrist/ Forceful or purposeful "flicking" is not required (or recommended).
@@DrDaveBilliards you call it what you want. Imagine throwing a baseball with speed or motion(curveball)...all these YT videos will never explain as easy as I've done.
@@ccurrivan See the videos and info at the link. Cue elevation actually reduces the amount of backspin and draw. Significant spin is lost on the first bounce as the CB is driven down into the table.
Chalk is critical to allow a large tip offset, but there are no real performance differences among all the popular brands of chalk. See the videos and info here: billiards.colostate.edu/faq/chalk/comparison/
*Contents:*
0:00 - Intro
0:53 - Background
3:09 - Study Procedure
5:30 - Study Results
6:09 - Acceleration Effects
7:53 - Speed Effects
8:59 - Wrap Up
*Specific Videos Mentioned:*
Top 10 Pool and Billiard Myths Busted and Debunked: th-cam.com/video/cdlQuEQcpRs/w-d-xo.html
Cue Tip Contact Myth-Busting Truths in Super Slow Motion: th-cam.com/video/HwayvH9z1hk/w-d-xo.html
STROKE TIMING … A Complete MythBusting Study of Stroke Acceleration Effects: th-cam.com/video/0m6g7lBh17c/w-d-xo.html
GOOD TIMING in Pool … What Does It Mean?: th-cam.com/video/XijiqaQyaGk/w-d-xo.html
CUE BALL CONTROL ... Everything You Need to Know: th-cam.com/video/fPQEBxbByD4/w-d-xo.html
*Supporting Resources:*
- stroke “best practices:” billiards.colostate.edu/faq/stroke/technique/
- draw shot technique advice: billiards.colostate.edu/faq/draw/advice-and-drills/
- stroke acceleration resource page: billiards.colostate.edu/faq/stroke/acceleration/
- stroke timing resource page: billiards.colostate.edu/faq/stroke/good-timing/
- cue tip contact time resource page: billiards.colostate.edu/faq/cue-tip/contact-time/
- cue tip hardness effects resource page: billiards.colostate.edu/faq/cue-tip/hardness/
- pool myths resource page: billiards.colostate.edu/myths/
- cue ball control tutorial: billiards.colostate.edu/tutorial/cue-ball-control/
*Subscribe to Dr. Dave's TH-cam Channel:*
th-cam.com/users/DrDaveBilliards
I always find it fascinating how, despite numerous years of study to obtain your doctorate, and a number of decades teaching and research, you still have the curiosity to continue learning new things, and the teacher in you never dies (to all of our benefit, I might add). Always have and will love your resources, Dr. Dave.
I'm glad you like my stuff. That's one reason why I love this wonderful game so much ... there is always something new to learn and apply. And it is challenging and fun to play well!
Love your work doc
@@Naptic I’m glad to hear it. I love doing the work.
Dr Dave. I personally cannot even find the words to appreciate this work that you put in. I wish someday your videos help me and others to jumpstart careers in billiards.
You're very welcome. I enjoy creating them.
@DrDaveBilliards education and effort does not a doctor make.
You need no education to be or be called a doctor. I'm always a bit skeptical when I see these DD videos and the math isn't presented/purported accurately.
@@cardguys FYI, I am a "doctor." I have a PhD in mechanical engineering. For more info, see:
billiards.colostate.edu/dr-dave/
www.engr.colostate.edu/~dga/
I also have a "Doctorate of Pool" from the BU:
billiarduniversity.org/testing/alumni/
So there. :)
pshhh@@cardguys
@@cardguys Nothing to say to Dr.Dave now? Everyone who watches his videos knows he is an actual doctor, just listen to the way he articulates himself in the videos.
I'm a big fan and you obviously debunk those myths. I do believe I have an important correction/addition: Cue stick angle of attack: you state repeatedly that the only thing that really matters is tip contact point and speed. But it is actually the full velocity vector (taking into account angle of thrust) that must be considered, not just the scalar "speed". This is obvious when you consider "jacked up" shots (to avoid double-cue-hit or when jacked up attempting draw over a ball or the rail): draw action is created even with a contact point that is above-center when considering a horizontal perspective - or even when considering the marks on the training cue-ball that you have. The affects should be material even for non-jacked up shots but where you vary how "unlevel" the cue stick is at point of impact
I probably should have mentioned cue elevation effects and that we were using a near-level cue on every shot. FYI, I cover draw shot cue elevation effects in detail via the info, videos, and links here:
billiards.colostate.edu/faq/draw/cue-elevation/
My takeaways from this that aren't discussed in the video, correct me if I'm wrong with any of these, Dr. Dave!:
Essentially, what this means in terms of strokes is that the "follow through" advice often given is not actually important in terms of implementing backspin on the cue ball but rather just a best practice to avoid decelerating the stroke too much before impact (i.e. hesitating to hit the CB as fast as you would like because you psychologically start the pull-back action earlier than when you would want to), given a certain goal of draw speed.
This makes sense because sometimes you're forced to pull back instead of being able to follow through on shots where the cue ball and object ball are nearly frozen to avoid a double-hit foul, but you can still impart strong backspin due to the shorter travel time of the cue ball to the object ball and nothing significant changes (in practice) with tip contact time.
This also further supports the idea that tip hardness is MOSTLY insignificant when it comes to spins and draw shots in particular. Or a better way to put it, there's no significant difference between tip hardness that you can't adjust for through practice with the same cue and tip, and will most likely only notice when you suddenly switch to a different tip type for the same exact shot.
That all sounds good. For more info on these topics, see:
billiards.colostate.edu/faq/stroke/follow-through/
billiards.colostate.edu/faq/stroke/acceleration/
billiards.colostate.edu/faq/cue-tip/hardness/
Anybody that plays pool and wants to get serious about it has to love Daves detailed videos. Theres so much false or inaccurate info out there and just because your a great player doesn't mean your a good coach thanks dave
Thanks. And I agree that great players aren’t always great teachers. Two different skill sets are required.
Years ago I formulated what I call a Fundamental Theorem of Billiards (FTB):
Provided the playing equipment is constant, the result of a shot is fully determined by:
(1) speed of the cue when it hits the cue ball,
(2) direction of the cue when it hits the cue ball,
(3) point on the cue ball that is hit by the cue.
FTB goes without proof, so it is more an axiom, but I liked the name. Some of the points can be merged using the concept of vector, but I find the above formulation most useful. For me FTB is basically a foundation that my game is built on. I used to think that FTB is a model/approximation that ignores some aspects of reality (e.g. timing), but is practical due to its simplicity. After watching this video I think that FTB is closer to reality than I thought before.
Many instructors teach it as ASS:
1.) Angle
2.) Speed
3.) Spin
drdavebilliardtshirts.com/product-category/humor/nice-ass/
@@DrDaveBilliardsA legend as always
Best pool content on youtube, hands down. Thanks again Dr Dave!
Thank you, and you’re welcome.
Agreed. DD is the best.
Thank you so much for all the effort you put into the videos. This is a model of how videos should be produced based on feedback. This puts to rest tons of anecdotal advice which is often incorrect (understandably so, due to lack of rigorous investigation, but incorrect nevertheless). This also furthers our understanding of the game - thank you so much!
I've busted lots of "anecdotal advice" over the years. See the videos, info, and links here:
billiards.colostate.edu/myths/
Thank you so much for all the work. I can see why people think that your tip is on the cue ball longer on a draw Shot with long follow through and acceleration. But I believe your test results 100%. Love your videos. I wish I had all this information when I was learning to play in the mid-60s. Back then everything was hush-hush and when you ask a good player for a pointer or how he hit a shot he would say you hit a million balls and you'll know how! Or something to that effect. Different times! Anyway thanks again thanks again for all your videos and hard work. Peace
You’re welcome. I aim to swerve. :)
Thank you very much for the link regarding cue weight.. I will read it with great interest!
I hope you get something out of it.
Great video! I don't know anyone else doing videos like these. Thank you so much!
Thank you, and you're welcome. If you are interested, more videos like this can be found here:
billiards.colostate.edu/faq/video/slow-motion/
Enjoy!
Nice myth-busting video. This explains why a friend of mine who uses a "slip stroke" can get so much draw action even using house cues.
Yep. Slipping the grip at impact has no negative effect on shot action. The cue does all the work at this point.
What is a slip stroke
@@rocconido2192 See: billiards.colostate.edu/faq/stroke/slip-stroke/
Dr. Dave - you're a true hero! Your testing methods and explanation styles are truly peerless in this sport.
It's fascinating to see how much of staple technique advice is really only a means to getting a person's arm to deliver very simple outcomes in terms of cue motion.
I'm curious if you've ever tried similar experiments but with a beginner with poor fundamentals? Both you and Pubo clearly are extremely accomplished players with extraordinarily consistent shot strokes, and I suppose you would struggle to play a badly-timed shot if you tried.
I would find it interesting and valuable to see which measurable factor(s) most often caused a bad draw shot for a player - was it contact point, or cue speed, or perhaps even another variable (perhaps you've ruled that out but would observing bad techniques help reinforce this?). I imagine the testing process would be a lot messier though so that may be offputting.
I already know from many years of teaching experience and observing countless league players what causes bad draw shot results. They are all listed and demonstrated in the videos here:
billiards.colostate.edu/faq/draw/advice-and-drills/
Enjoy!
PS: I am very good at demonstrating bad stuff. I had lots of experience in the past.
You approach this like a scientist. Thanks for the videos.
Science is the only way to solidly debunk ingrained misconceptions and myths. You're welcome.
@@DrDaveBilliards Yes! Assumption is the mother of all fudge ups.
You are amazing! I am an engineer and really appreciate your detail research and studies and great demonstrations on this amazing game! 🙏👏👏👏
Thanks. I’m glad you like my stuff.
Thanks for clearing up some of the the myths in the game of pool!
You're welcome. If you want to see many more myths busted, check out the videos and list here:
billiards.colostate.edu/myths/
Enjoy!
Science will always prevail. As I have said before, "I quit arguing tip hardness, contact time, and which will generate more cue ball spin years ago." It is because of Robert Byrne's teaching videos (yes VHS, I'm old) and Bob Jewett's slow motion studies, I believe it was called the Jacksonville Experiment or Project, I have the PDF files saved somewhere from years of digging back in the late 90's on this subject. I am rambling but have always used a hard tip from what Bob Byrne's taught. Great video, as always.
I also prefer a harder tip for the reasons here:
billiards.colostate.edu/faq/cue-tip/hardness/
FYI, all the Jacksonville Project info can be found here:
billiards.colostate.edu/faq/video/Jacksonville-Project/
@DrDaveBilliards always great info on your colostate page. Thank you for all of the information you provide that is backed up by applied science/physics. Great stuff.
@@brianboyer6801 You’re welcome, and thank you. I aim to swerve. :)
Dr Dave. Thank you for your hard work. I've enjoyed your knowledge for many years! My question is this: F1 race cars used to use super soft qualifying tires that wore out in one lap. Why don't we use soft rubber tips on our sticks? Seems like an optimum compound could be created for this purpose.
Second question: How does the chalk build up on filthy bar boxes effect ball action on draw and throw?
Thank you once again!
First: A really soft and bouncy tip would extend the tip contact time too long, creating far too much CB deflection. See:
billiards.colostate.edu/faq/squirt/cause/
Second: A dirty cloth could contribute to an increased change for cling/skid/kick (excessive throw), especially if the balls are dirty with body oil that might pick up the chalk dust. A dirtier cloth definitely makes it tougher to draw the ball. See:
billiards.colostate.edu/faq/throw/cling/
billiards.colostate.edu/faq/table/cloth-effects/
Hi Dr Dave, if F(force) = M(mass) X A(acceleration), then why is more force not applied to the cb with more acceleration at a given cue speed?
The important forces are the extremely large impulsive forces between the tip and CB that accelerate the CB. The effect of the relatively miniscule forces being applied by the grip hand on the cue are unimportant to the motion of the CB. For more info, see:
billiards.colostate.edu/faq/grip/light-vs-tight/
billiards.colostate.edu/faq/stroke/acceleration/
billiards.colostate.edu/faq/cue-tip/contact-time/
Awesome study, thanks! Theoretical understanding and discussion is fun, but nothing beats a good old fashioned empirical experiment!
I'm glad you like it. I agree. Science is cool.
Dr. Dave. I think this is wonderful and proves your point experimentally. Well done! And thanks for your responsiveness.
I think it would be great if you use your partner and his setup to examine cue stick angle (up to several degrees anyways) to determine its effects on draw as well as on force follow (where some insist there's a huge difference from angle and finishing UP is critical.
At about 2:50, you show a chart of cue speed vs time. Is this chart real? Does it really represent the results of different strokes and that there's a particular type that uniquely results in that higher speed needed for more draw? If so, I think that deserves and I would appreciate some followup to explain it, including what's necessary to achieve that. Hitting low on the cue ball has been beaten to death, but there's little information about this acceleration technique. Is it impacted by bridge length or backstroke length, wrist action, muscle fiber types or what? How would you practice it and recognize progress (I mean as a dry practice or just with a cue ball), working up to doing actual draw shots?
I honestly don't feel a need (nor do I have the interest or motivation) to do additional tests related to this topic. I have already beat it to death (per all the past videos linked in the video description). Also, the science on most of these topics is already clear. See:
billiards.colostate.edu/faq/draw/cue-elevation/
billiards.colostate.edu/faq/draw/physics-advice/
billiards.colostate.edu/faq/stroke/acceleration/
billiards.colostate.edu/faq/cue/weight/
billiards.colostate.edu/faq/stroke/follow-through/
First I want to say thanks for all your hard work, you provide a lot of good information!
However:
Striking as low as possible, with elevation can provide more draw in certain circumstances. The elevated cue will cause the cue ball to skip across the table. Less contact time with the table, less backspin loss.
Sure it’s difficult and adds another degree of complexity which makes the shot more missable, but doesn’t change the fact that what you’re stating is only applicable to your testing conditions. (Your table, felt, temp/humidity)
You're welcome.
Cue elevation can narrow the draw angle per the info and demos here:
billiards.colostate.edu/faq/draw/quick/
But cue elevation does not help create more draw for the reasons here:
billiards.colostate.edu/faq/draw/cue-elevation/
The CB loses more backspin on the first bounce than is saves by being airborne.
And you are correct. Cloth conditions play a huge roll:
billiards.colostate.edu/faq/table/cloth-effects/
This may or may not apply here but Fedor Gorst talks about "pushing" the cb as opposed to hitting it. I would imagine the contact time would not change. Might be an interesting collaboration on the subject.
What a player thinks and feels isn’t always what actually happens.
@@DrDaveBilliards Fact, but would still be an interesting video. Thank you for all of your effort. A priceless library of information.
@@robertreese2600 Agreed. A collab with Fedor would be awesome. I’m glad you like my content. You’re welcome. I aim to swerve. :)
Excellent video!! Thanks Dr. Dave!
Thank you, and you’re welcome.
thanks for the great effort to demo this for us! Will the weight of the cue matter here? I assume heavy cue with the same speed will translate into more energy， right？
That is correct, assuming you can stroke the heavier cue at the same speed. See:
billiards.colostate.edu/faq/cue/weight/
You have the soul of a scientist.
Although insufficient data, it looks a bit like a step down transition point in the 395 to 415 cm/s speed range? If a real effect, maybe a threshold in tip compression or shaft flex?
More data (and more careful measurement of tip contact height (maybe by observing chalk marks on the CB) might have helped. Also, the effect you are seeing might be somewhat exaggerated by the small scale range on the vertical axis.
Wow! Very informative and interesting!
I really enjoy learning something new!
Cheers!
Hey Eric! I'm glad you like it (and learned something).
Great work, Dr Dave. However, I am not sure if your conclusion to the shot at 7:12 is correct as the two cues are travelling at basically identical speeds if you compare them frame by frame. I was expecting the "accelerating" cue catching up with the "decelerating" one instead.
I agree it is difficult to see the difference in acceleration over a short distance like this, but the calculations from the data show it clearly.
@@DrDaveBilliards @DrDaveBilliards You are right that for example, in shot No. 8 with a=-1155cm/S^2 and v=408cm/S, the velocity should be at around 409cm/S just a millisecond before the impact. However, with the resolution of roughly only 30 pixels/ms from your table at 4:08, I wonder what are the precisions of your velocity and acceleration measurements?
@@laitaumou1043 I will let @PuboH reply to this one since he did the detailed analysis of the data.
@@laitaumou1043 The two shots have impact speeds 408cm/s and 412 cm/s. So they only differ by 4cm/s. The clip shows the last 105 frames until impact. Since the footage was recorded at 19783 fps, that corresponds to 0.005s time elapsed. During this time interval, two cues would have traveled distances only 0.02cm = 0.2mm different, which is about width of 4 human hair.
@@laitaumou1043 I'm not quite sure what you mean by the precision of the measurement. If you mean sampling rate, the velocity and accelerations are all calculated from the position data of the cue, which is tracked frame by frame, so 60 data points/second. Of course the data are then turned into smooth polynomials for ease of differentiation. If you mean the accuracy of the tracking, I don't really have a good way to quantify this, since I used python packages and after effect, and I don't know how they actually implemented the algorithms, therefore neither its accuracy.
Thank you Dr Dave!
I've been wondering the whole video how would changing the cue angle (elevation) would affect the draw shot / contact time, with the extreme example being a masse shot but for example a draw shot from the rail or over a ball, what would make a big difference in that case?
For information and demonstrations of what cue elevation does to draw shots, see the resource here:
billiards.colostate.edu/faq/draw/cue-elevation/
and here:
billiards.colostate.edu/faq/draw/quick/
Highly elevated masse shots are a different story:
billiards.colostate.edu/faq/masse/
Nice.. How do different cue weights change this? Do we have to talk about "impulse" instead of "speed"?
The weight of the cue influences how a player is able to accelerate the stick (the heavier the cue, the lower the max. speed). But a heavy cue does not have to be as fast as a lighter cue to impart the same impulse to the cue ball.
Hypothesis:
If you are srtong or very skilled, you might choose a lighter cue and generate the impulse with your muscels. If you are weaker or unskilled use a heavier cue and let the mass do the work.
This topic is covered in detail here:
billiards.colostate.edu/faq/cue/weight/
billiards.colostate.edu/faq/draw/cue-weight-effects/
Thank you for the video.
I was wondering; if one wanted to maximize draw/speed ratio with cut shots (quarter-ball hit or more), would jacking up help in that case? I would think that in the extreme case, the cue moving directly downward towards the table while hitting CB at the six o'clock mark, would maximize this ratio. On the other hand, the CB starts to get pressed against the table somewhat when you jack up the cue (and maybe even little bit of jumping may occur?).
The problem with draw and thinner cuts of course is that CB retains more of its own speed after contact with OB, and the higher "residual" speed causes it to travel along the tangent line further before the draw can take effect.
Cue elevation reduces backspin but it can narrow the draw angle. See:
billiards.colostate.edu/faq/draw/quick/
billiards.colostate.edu/faq/draw/cue-elevation/
Have you ever used or considered using a slight funnel shape tip? Do you think the additional contract area, would allow for more controlled spins without misscuing?
It seems to me that would create less contact area with an off-center hit.
So, making a “jab” stroke on the draw shot would have the same outcome as one with a smooth follow through, assuming the speeds were similar?
Yes. For more info, see:
billiards.colostate.edu/faq/stroke/type-and-quality/
So just hit it faster. Check!
Can you study why some players hit the cue ball quite slowly but still get great cue ball movement? Like, say Fedor Gorst style for example?
Low and fast is all it takes. Draw looks effortless for some players because they use a longer stroke length and accelerate very smoothly. When done well, it takes less effort, but the cue speed at contact is the same. For advice on how to do it, see the videos and info here:
billiards.colostate.edu/faq/draw/advice-and-drills/
Do you have the result videos on shot 24 vs shot 25 and 36 vs 261? same position , same speed , different contact time ..........although he didn't change cue tip hardness. Maybe more clear to change the hardness and cross compare again.
I could have shown more shot comparisons, but I didn’t want the video to get too long. Regardless, the graphs showing the results for shots clearly show the important trends. FYI, cue tip hardness effects are covered in detail here:
billiards.colostate.edu/faq/cue-tip/hardness/
Does a smaller diameter tip allow for a miscue limit hit further away from CB center, and would that produce more backspin with any given cue speed? What effect if any, does the diameter of the tip have on the maximum amount of spin that can be generated, and is there an optimal diameter assuming that cue speed remains the same? Do low deflection shafts perform better or worse than old school shafts with heavy ferrules when it comes to maximizing backspin?
Answers to these and related questions can be found here:
billiards.colostate.edu/faq/cue-tip/size-and-shape/
billiards.colostate.edu/faq/cue/low-squirt/#spin
@@DrDaveBilliards Excellent studies, but there has been no examination of the effects of an applied downward acceleration of the grip hand just prior to cue tip contact. This upward angle cue tip acceleration opposes the cue tip deflection that will happen following impact, and is the pro nuance for obtaining maximum backspin. You are doing this acceleration yourself as can be evidenced by the raised to level tip position on shot completion in the videos of your maximum draw shots. I also noticed (in this slow motion video) that the radius profile of the tip was starting to flatten somewhat at the upper shoulder where repeated contact was occurring, and this may have contributed to more scattered and inconsistent results concerning the precise offset of that shot.
What about grip tightness? I still think a tight grip at contact point give the cue ball more speed & more draw action (because it adds mass to the cue). Maybe you could debunk that, here is a suggestion for testing:
- 2 shots, with same cue speed & cue acceleration at contact point, same contact point; the only difference is, one with a lose grip and one with a tight grip (at contact point). Then we measure the speed of the cue ball, the spin (how many round per sec), and the draw action (how far the cue ball goes back). The result will settle this problem once and for all.
See the info and links here:
billiards.colostate.edu/faq/grip/light-vs-tight/
Can you breakdown/analyze some unique strokes like Chris melling.
How can he shoot so accurately with such a long stroke is crazy
Chris does pretty much all of the stroke "best practices" broken down and demonstrated here:
billiards.colostate.edu/faq/stroke/technique/
Some people just sort of have "it". Alex Higgins looked like he was having a seizure while he was down on a shot and he was world snooker champion twice.
@@myyoutubename4067 Any technique can be mastered with enough practice. “Best practices” techniques are easier and faster to learn and master for most people.
Its true that acceleration doesnt mean much due to brief contact time, but contacting the cueball when your cue is accelerating mostly translates to a higher cue speed upon contact.
Teaching the acceleration portion while teaching draw is still relevant in my opinion, especially in imparting a proper stroke or getting more reaction. I found it effective in teaching draw by slightly reducing the pull back and increasing the follow through so as to contact the cue ball while the cue is accelerating to attain a higher speed at time of contact.
I dont want to be teaching the "unimportant stuff" or "wrong stuff", but i cannot find a more effective way in teaching draw without using the word "acceleration".
As I pointed out in the video, smoothly accelerating stroke is critical to accuracy, consistency, and speed control per all the info and advice here:
billiards.colostate.edu/faq/stroke/technique/
But most good players reach maximum speed (with zero acceleration) just before contact. Per the info and study link here:
billiards.colostate.edu/faq/stroke/acceleration/
If you are still accelerating at impact, it means you didn’t accelerate and generate speed early enough. Many players actually decelerate just before contact due to poor timing:
billiards.colostate.edu/faq/stroke/good-timing/
In my mind, the FEELING of acceleration at impact is extremely important to a good stroke. As Dave said, it is the best way to be accurate, and, importantly, consistent. With the use of these slow motion videos, we can understand that what we’re feeling isn’t what is actually giving us the results, but if this feeling is the most effective way to be accurate and consistent, then by all means, use it.
@@jonathangoff8005 Well stated.
That’s surprising - good to know. I’m just curious your view on it - obviously for most physics problems you just need the force vector of impact to calculate a trajectory since all the information is encoded and the lead up doesn’t matter.
I guess the contact time makes no difference because of the time frame of which you’re extending it? Makes it negligible?
With collisions, the contact time is not really important. What is important is the momentum of the cue. I try to explain it a little more here, along with other useful supporting links:
billiards.colostate.edu/faq/cue-tip/contact-time/
The efficiency of the hit (which is mostly related to tip hardness) is also a factor. See:
billiards.colostate.edu/faq/cue-tip/hardness/
Another great video. Thank you.
Thank you, and you’re welcome.
Hey Dave... does the roundness of the tip determine the lengths of tip contact? I would think the more round the tip the more surface of the tip is contacting resulting in more spin.
No. FYI, all tip shape and size effects are covered in detail here:
billiards.colostate.edu/faq/cue-tip/size-and-shape/
Now, tip hardness does affect tip contact time. See the videos and info here:
billiards.colostate.edu/faq/cue-tip/hardness/
@DrDaveBilliards TLDR; Is quality shaft important for the success of full length table power draw shots?
Back story: I play exclusively in bars and pool halls on 9 feet tables. Often times the cloth is smooth and fresh. I use the basic cue stick available at their disposal as I yet have to get one of my own. I play 1-2 times weeekly for the past 2 years, so I have a solid amount of experience.
I am wondering why when attempting power draw shot across full table length I either scoop the cue ball or the ball loses most of it's spin and the ball returns only about third of the table. I can rarely get the cue ball to return half table length when practicing draw shot and in actual game the success rate is even lower.
Is it reasonable to blame the bar cue sticks which aren't as stiff supposed to a professional cue stick?
Cue tips are hard and round on all of them so i think I can rule this out.
It might very well be lack of speed as I'm not in a great physical form, but that's not what I would like to be blamed for even tho I'm sure that's also part of the problem.. 😅
The cue is not so important, assuming the tip holds chalk (and is chalked), and assuming the shaft and ferrule are not cracked. Getting good and consistent draw is all about good technique. If you want help, see the videos and info here:
billiards.colostate.edu/faq/draw/advice-and-drills/
The cloth type and condition are also important:
billiards.colostate.edu/faq/table/cloth-effects/
Over long distance, you can also jack up slightly and not hit as low to get the ball to jump slightly so the back spin doesn't wear off as fast. The cue ball also has more speed compared to cue speed because you are hitting closer to center so it gets to the object ball faster and again has less time to lose back spin. This effect also helps even if you don't jump the cue ball. The hard part is picking the right spot on the cue ball to balance all effects to get maximum draw especially when you take into consideration distance to the object ball and cloth conditions (don't even start on barbox cueballs).
Jacking up the cue more than is necessary to clear the rails does not help draw distance. For the reasons why, see:
billiards.colostate.edu/faq/draw/cue-elevation/
Although, cue elevation can help narrow draw angle. See:
billiards.colostate.edu/faq/draw/quick/
It reall does. You are focused on increasing spin. Jacking up does not increase spin, it just causes the cue ball to stay airborne so it doesn't lose spin due to friction. Try it. If you can get the cue ball to reach the object ball in 2 or fewer bounds, it will dramatically increase effective draw if the cue ball is more than 5 diamonds away from the object ball and especially if you have slow cloth.
th-cam.com/video/dnTzqTc8IKg/w-d-xo.htmlsi=HQ6IU68cjT6W4-a8
Here's my draw shot btw
@@Gotwired I have tried it. I can get more draw with the cue as level as possible (on any cloth). I have also done a careful and thorough physics-based analysis. For the reasons why an elevated cue does not help (unless the cue elevation helps you generate a more powerful stroke for some reason), see:
billiards.colostate.edu/faq/draw/cue-elevation/
I think these myths still get spread because they change how people think of their cue delivery, like they hear "accelerating with good timing" and maybe slow down the backswing (resulting in less unwanted steering) and a faster forward swing (resulting in greater draw distance). Then the figure "well what I was told is working, and it sounds scientific, so the info must be accurate". Like the old adage "it's hard to argue wth success".
That, combined with people's natural reluctance to ever back down when arguing on the internet, means the debate will probably go on forever.
Well stated.
Hi Dr Dave
One thing that I have wondered about is the effect of the weight of the cue for different players. It is probably highly individual. A light cue would probably be faster but that would give less momentum and as such give less draw or other effect at some point. I wonder if there is some way of finding out the optimal weight of a cue for different players in case you don't have a speed camera. Could you please give your wives on this subject.
FYI, this topic is covered in great detail here:
billiards.colostate.edu/faq/cue/weight/
I'm curious what the effect of cue tip deflection has on the quality of draw and follow shots. Would it be possible to build a rig that imparts 0 deflection upon striking the cue ball? Maybe a roller or plastic "sled" that attaches to the tip. If the tip doesn't deflect at all upon impact, would it force the ball to hop? I think this information. Would be useful in determining the right type and size of shaft to play.
With an off-center hit, the tip always flexes away from the CB (most after the hit). If the shaft were stiff and heavy enough to prevent this, there would be a huge amount of CB deflection (AKA squirt). For more info, see:
billiards.colostate.edu/faq/squirt/cause/
Concerning the right type of shaft, see:
billiards.colostate.edu/faq/cue/carbon/
billiards.colostate.edu/faq/cue/low-squirt/
Concerning shaft size, see:
billiards.colostate.edu/faq/cue-tip/size-and-shape/
Fascinating.
I'm glad you think so. I hope the disbelievers think of it that way also. :)
I also experiment a lot with pool billiards. However, I don't put in that much effort into measuring.
I work with very different ferrule diameters. (usually between 12.9 and 10.5 mm)
What becomes clear here is the contact point of the top edge of the tip. This seems - also based on the measurement - to be significant for the draw result.
With a thicker tip diameter, the bottom edge is very close to the base plate at the point of contact, while when using the thin tip size the rule clearly applies that you have to aim for a tip width above the table width.
As far as the hardness of the leather is concerned (that wasn't the topic in the video), I always notice that long draw shots are subjectively easier with harder tips. Energy transfer certainly plays a certain role, which results in acceleration. In my opinion, the grip of the leather surface should also be examined in more detail (roughness in interaction with chalk characteristics), although this property is more relevant for short distances and applying side spin.
See:
billiards.colostate.edu/faq/cue-tip/size-and-shape/
billiards.colostate.edu/faq/cue-tip/hardness/
I look forward to seeing players pull those charts out and referring to them before their draw shots .... 🤓👍
I don’t. That would be silly and unhelpful. :)
@@DrDaveBilliards : I think it would be good comedy! But, I suppose it could be seen as sharking . . . Except with a time clock . . 😐🧐
@@rogerscottcathey It would seem more like reverse sharking (“fish” acting) to me. :)
I have a request. A little backstory. Some time back you did a video regarding spin and correlation to tip hardness. IE phenolic vs leather you probably remember. I was out shooting a week or so ago and had a guy grumbling about his tip being too hard to get spin on the same token, I could clearly see, he wasn't getting the spin his cue path should have generated.
I took a look at his tip and it was near flat. He was using less than 1/16 of the available surface and expecting it to grip. I tried to explain to him the shape of the tip has more impact on spin than the hardness, but...well, naturally he "knew better".
Could you please make a video comparing different tip shapes and their effect on spin? This could even possibly down the road lead into something on the importance of tip shape retention. But I digress, where was I. Oh yeah, but such a comparison video would make explaining such things easier, especially from a reliable source that you are.
This is on my list of things to go, but in the mean time, I cover the topic in detail here:
billiards.colostate.edu/faq/cue-tip/size-and-shape/
Fantastic video!
Thanks! I’m glad you liked it.
Excellent!
Thanks! I'm glad you thought so.
so... low,, fast, and straight... right? For maximum draw...
Yep. For advice on how to do this, see:
billiards.colostate.edu/faq/draw/advice-and-drills/
One thing I've always wondered is if the particular dome radius the tip is shaped to has a significant impact on how far you can hit the cue ball below the middle at iso speed without miscueing.
The tip shape is not as important as some people might think. See:
billiards.colostate.edu/faq/cue-tip/size-and-shape/
@@DrDaveBilliards Thank you for taking the time to reply, interesting read. It always strikes me just how many tiny effects are involved in producing the final motion, even if the general physics involved seem to be obvious enough at first. I guess that is mostly a result of using perfectly hard and smooth model materials in our heads when we make calculations, while cloths, tips, cues and balls all have their own material properties that make them anything but perfect model materials. The effects may be small, but they can add up on certain types of shots. I didn't think I'd ever get any answers to these lingering questions I've always had playing various cue sports over the past twenty years, but thanks to yourself and others, the research is finally being done.
@@osirisgolad You’re welcome. I aim to swerve. :)
Ahhh I love the smell of science in the morning 😁
I like it. 👍
This is why you want a super hard tip and good chalk. This transfers momentum more
efficiently.
But the sound of impact might not be very pleasant 😂
I wonder if a super hard tip might slip more with lower contact points? Less tip deformation reduces contact area which might result in less frictional resistance?
@@nitrostudy9049as long as the tip is holding chalk properly then it shouldn't matter. Point of contact is already extremely small so the only difference between tips is that the soft one may hold chalk slightly better than the hard one, but if you're thorough at applying chalk then the tip shouldn't slip.
For those interested in these topics, see the videos, info, and links here:
billiards.colostate.edu/faq/cue-tip/hardness/
billiards.colostate.edu/faq/cue-tip/efficiency/
billiards.colostate.edu/faq/chalk/comparison/
How much of an effect does the width of the tip have?
I would assume with a thinner tip one could strike lower on the cue ball and ergo generate more draw
This is true only if you use outrageously big tip. If your tips are 10mm vs 30mm. Then yes because you cannot hit the miscue limit using a 30mm tip. But for the common tip sizes ranging from 9-14mm, you can hit the miscue limit regardless of your tip sizes. If you use a 14 mm you need to lower the tip more than with a 9mm just because of the geometry. But as long as you hit the same place on the ball with the same speed, the results should be almost identical (considering your two cues and tips might be a little different in weights)
Pubo is correct. For more info and illustrations, see:
billiards.colostate.edu/faq/cue-tip/size-and-shape/
I think an interesting case study in draw action would be Jayson Shaw. He has a fairly compact stroke, and doesnt hit the ball exceptionally low, yet can generate a tremendous amount of draw. I notice on his power draw shots he gets a bit wristier and looser in his hand, which increases the speed. He also has a very well timed snap which produces a lot of power, similar to kinetic chain linking in a golf swing. I suppose there is a sliding scale of speed and tip position. He must generate enough speed to compensate for the tip being higher than, say, Jeff de Luna.
Another example is Judd Trump.
A good stroke combined with some wrist action is often used to get a very very high cue speed with easy. I often use more wrist when playing larger draws.
i love this video!
I'm glad to hear it.
Thank you Dr Dave for yet another excellent video.
So technically it turns out a follow through is not really needed after all.
Also, it would be interesting to see a similar experiment but done with two different cues, say a very cheap one and one with a carbon fiber shaft. Ideally both having the same tip and similar weight, too. Just to see if the draw action changes if the shot is played with exactly the same speed and tip contact point.
A follow through is not really needed, but it is almost guaranteed to happen with a good stroke. See:
billiards.colostate.edu/faq/stroke/follow-through/
What does it mean when the balls don't bounce off the cushion perpendicular to the angle they approach? My rails are in good condition but seem to eliminate zig zag causing the ball to not travel down the table but to bounce back and forth between the opposite rails or even come backwards. My guess is that my 2" balls are too small for my cushion nose. According to my math, if I use 2 1/4 inch balls, my cushion nose height (28mm) will just be above the centre height of the ball.
I'm confused because the pocket size seems to demand 2" balls but the cushion nose height is perhaps suited for 2 1/4"?
@@lukeforsyth792 See:
billiards.colostate.edu/faq/table/cushion-nose-height/
@@DrDaveBilliards th-cam.com/video/mVhcS4hpd6g/w-d-xo.htmlfeature=shared
That's Dr. Dave and Pubo Huang for working on this myth busting. I've long been convinced that those guys with "super draw" are simply hitting the cue ball nearer the miscue point that those who seem less able to get significant draw. Nobody likes to look like an idiot by miscuing, so they don't strike as low as they could. What this means to me is that one SHOULD be miscuing on a regular basis in practice, in order to familiarize oneself with the miscue point, and learn how to come very close and still not miscue.
Thanks! Actually, it is better to hit slightly above miscue limit and with slightly more speed. This way you don't risk too much miscuing and can get as much draw too!
They are hitting the ball low, but they are mostly generating more cue speed (with smooth acceleration over a long stroke length). Concerning Pubo's point, see the videos and info here:
billiards.colostate.edu/faq/draw/power/
@@DrDaveBilliards Virtually anyone can hit a ball hard (and "hard" can only mean with more speed). Not everyone is good at hitting maximally low without miscuing. Virtually everyone knows that it's necessary to hit the ball hard to get a lot of draw -- yet not everyone GETS that draw. It can only be because they don't hit the ball maximally low. It takes NO CONTROL to hit a ball hard, it takes a lot of precision to hit a ball very near but not AT the point of miscuing.
It appears that accuracy is the most important. Therefore, if the quality of rhe stroke affects accuracy, then it matters.
No doubt about that.
Dr. Dave do you think you could make a video either explaining the benefits of using a bigger shaft say 12.5 compared to say a 11.5 or smaller. I always hear that a large shaft is more forgiving but is it really and what is the advantage of each. That might be interesting. If you have already address this I must have missed it. Thanks.
FYI, I cover this topic in detail here:
billiards.colostate.edu/faq/cue-tip/size-and-shape/
hello dr dave this has nothing to do with the video but the table that i play on at my local pool hall has a weird problem one of the cushions deflects the ball with more speed so if i roll the cue ball into it it comes back with more speed any ideas how this could happen?
The height of the cushion nose is probably a little low, or maybe the other rails are not as solid. See:
billiards.colostate.edu/faq/table/cushion-nose-height/
@@DrDaveBilliards it is probably the cushion nose height since the table does bank short as well thanks for the quick response
Rail nose height can cause this, most commonly when the rails are reclothed. Another possibility is a rubber was changed on this rail, and it performs differently than the others. This happens on commercial tables generally, where sometimes only the "bad" rubber gets replaced, as opposed to a full set.
Thanks for the continued great content Dave - definitely a game changer for teaching and explaining draw principles 👍
@@shortbus3300 You're welcome. Good point about the cushion rubber possibly being changed.
mindblown!!!
Hopefully, in a good way. :)
my drunk ass didnt understand a thing but still paid full atention to this vdeo. great as aways ! please doo a video on diferent rules, like russian brasilians and snooker !
Maybe you can watch it again and absorb more when you are sober. :)
I don’t play or honestly have much interest in those other games, so I’m probably not the best person for the job. Good idea though.
I recently started going to a place near me. Got a new cue also. But all the sudden I CANNOT draw for crap anymore. Where I'd expect a 2-3 foot draw, I get a stop shot. Idk what's going on. Not sure if my tip is messed up or the tables are.
The advice and videos here might help:
billiards.colostate.edu/faq/draw/advice-and-drills/
@@DrDaveBilliards Yeh, it's the tables.
so wild you're saying gripping the stick too tightly has nothing to do with my shot...
I'm not saying that at all. What happens with cue acceleration or the grip hand during the incredibly brief moment of cue tip contact has nothing to do with the action of the shot, but having good fundamentals (including not tightening the grip) has everything to do with delivering the cue with the desired speed and tip contact point with accuracy and consistency. See the videos and info here:
billiards.colostate.edu/faq/stroke/technique/
billiards.colostate.edu/faq/grip/technique/
billiards.colostate.edu/faq/stroke/good-timing/
billiards.colostate.edu/faq/stroke/acceleration/
Enjoy!
yes sir thanks.@@DrDaveBilliards
I completely understand and agree with the physics involved, but in order to be consistent, a repeatable stroke is an absolute must, and good mechanics promote that. Otherwise, what difference would solid mechanics make? And judging by all the greatest players having excellent fundamentals, I'd venture to say that it does matter.
I’d tried to make this point at the beginning of the video. Good fundamentals, timing, and acceleration during the forward stroke into the ball are critical for accuracy and consistency, but what is happening at the instant of contact is unimportant. The videos and info here cover all the important stuff concerning a good stroke:
billiards.colostate.edu/faq/stroke/technique/
billiards.colostate.edu/faq/stroke/good-timing/
billiards.colostate.edu/faq/stroke/acceleration/
@@DrDaveBilliards It's a great video, as are most of yours. My background is in engineering and I think like you. My friends have argued with me multiple times about the chalk and tip hardness video results. A similar video about weight of a break cue, and I think that'll round out the arguments, lol. I keep trying to tell them lightening the cue can get you more power (assuming you can generate enough velocity). Some just don't understand the concept of mass x velocity squared.
Keep up the good work!! And thank you.
@@joncue0304 Check out and have your friends check out this page that covers cue weight questions in great detail:
billiards.colostate.edu/faq/cue/weight/
That should settle the argument.
Will do! Thank you.
@@joncue0304 Let me know how it goes.
I really need help . Sometimes i cant hit a slow straight draw shot . Im a big guy (1.95m) and i feel like im either off balance or it feels like i throw a spear into the cueball because i hold the butt of the cue with only the index finger. Seems like i need a longer cue . I think im off balance and when i try a long enough bridge my pendulum stroke has bad technique
you need to work on your shot routine, 100%. You need to be getting down on the ball the same way and into stable, good position for every single shot, regardless of shot type. If you are struggling to get consistent draw, you are not hitting low enough on the cue ball with enough power, it's really as simple as that. You should never, ever be holding the butt of the cue with 1 finger, that is totally pointless and harmful to your game. The length of your cue does not matter in the slightest if your fundamentals are all wrong, put the cue length out of your head entirely, whatever you're using now is probably fine
The advice in the videos and other info here might help:
billiards.colostate.edu/faq/draw/advice-and-drills/
You always know 👏👏👏🎉
... only after doing the "science."
@DrDaveBilliards Well you wrote it down, so it isn't just playing-it's science!
nice,
Thanks.
What about those who swing there cue tip downwards as it’s contacting the ball
This can result in more backspin if the downward motion creates a lower tip contact point, but the swiping motion is not helpful. See the videos and info here:
billiards.colostate.edu/faq/stroke/swoop-swipe/
Some assumptions need to be cleared up, F=MA. So where the force is imparted and how that force is imparted is all that matters.
So bridge hand and blah blah blah do not matter, but the speed and mass of the cue stick and location on the cue ball are ALL that matter.
Dr. Dave, you're not a stats guy. Those 5:40 and 6:00 data points do not actually speak to a linear regression. Although the regression can be calculated, if there isn't an appreciable trend, the regression means diddly.
Understood, but the upward and downward trends do seem clear (even if not perfectly linear with a strong correlation).
Dave was never a real scientist, so don't bother. You'll just hurt his feelings, and never get a straight answer. He aims to swerve (around hard questions). He's a glorified H.S. physics teacher...and a wannabe science popularizer.
@loum5254 See:
billiards.colostate.edu/dr-dave/
www.engr.colostate.edu/~dga/
You are correct. I was never a "scientist." But I have a PhD and was a university mechanical engineering professor for 30 years.
@loum5254 ha. That's a little harsh, but it sounds like you've some experience with him. I've dropped it. Thanks for the heads up btw
@@DrDaveBilliards You do know that you can actually compute a correlation coefficient, right Sloppy Dave? PhD...haha! You stink.
In my humble opinion, all contact time is 1/1000 of a second. Do the measurements at 1/10,000 and the ones at 1/100,000 of a second longer that 1/1000 of a second mean anything? No, I don't even think you can see a difference of 1/500 contact time let alone between 1/10,000 or 1/100,000 of a second. It's like computer memory. "I'm upgrading 2400 MHz to 3000 MHz because I want faster speed." Will you see anything "faster" happen on your computer because you increased your speed by 600 MILLION cycles per second when you already have 2,400 MILLION cycles per second? No. So anything more that 1/1000 second is measurable, but not a factor.
There are changes in tip contact time with tip hardness and shot speed; but, as you point out, these differences are unimportant per the info and videos here:
billiards.colostate.edu/faq/cue-tip/contact-time/
@@DrDaveBilliards Thanks Dave. And as a user of both the Illustrated Principles book and cd, I appreciate all you do for the billiard community!
@@Kevin-mm6xm You’re welcome, and thank you!
It's called, flicking the wrist motion. Nuf said!
I think it is instead a "relaxed wrist along for the ride" motion. See:
billiards.colostate.edu/faq/stroke/wrist/
Forceful or purposeful "flicking" is not required (or recommended).
@@DrDaveBilliards you call it what you want. Imagine throwing a baseball with speed or motion(curveball)...all these YT videos will never explain as easy as I've done.
wow.... what a study
DAM right! :)
Felt type also matters
Yep. See:
billiards.colostate.edu/faq/table/cloth-effects/
It would be great if someone could translate it into Chinese...
Pubo translates many of my videos into Chinese and posts them on BiliBili here:
space.bilibili.com/11973780
He plans to translate this video soon.
@@DrDaveBilliards 非常感謝，thank you very much
今天应该就翻完了，敬请期待！@@吳哲榮-k8y
@@吳哲榮-k8y You're welcome.
Have you done a study on the height of the butt comparison?
See:
billiards.colostate.edu/faq/draw/cue-elevation/
@@DrDaveBilliards How about butt elevation creating a slight jump so backspin doesn't wear off as much at long distances?
@@ccurrivan See the videos and info at the link. Cue elevation actually reduces the amount of backspin and draw. Significant spin is lost on the first bounce as the CB is driven down into the table.
Yeah- how does the chalk factor into all of this though?😭
NO difference as long as the chalk prevent the cue from miscuing!
Chalk is critical to allow a large tip offset, but there are no real performance differences among all the popular brands of chalk. See the videos and info here:
billiards.colostate.edu/faq/chalk/comparison/
Some feathers are bound to be ruffled here
I love ruffling feathers to help correct common misconceptions.
Sloppy work, as usual, Dave.
I assume you're joking. If not, please show us your test results.
'Promosm' 🤷