It's funny I never understood what an x-wing is and even tutorials didn't help, mainly because most of them are in English. He just colours one in and talks about it and I instantly got whats meant. Now I'm annoyed at myself that I didn't understand something so obvious. Thank you very much.
I didn't use the X-Wing, instead I used the crank-handle pattern (as Simon calls it) between columns 2 and 8 for the 8's. The crank handle pattern immediately gives a 6 in column 5 and then you just have to watch the sudoku fall apart. It felt wonderful getting it, my first crank-handle :D
such a satisfying puzzle to see unfold. been trying to up my classic game lately and I think this video will prove extremely helpful-- not just for the x-wing tip (brilliantly demonstrated btw), but the way Mark scans and asks the question "where can a x go in this row/column?" is just something that often evades me while i'm solving. there were a few times early in the video where I thought to myself "I wouldn't have spotted that nearly that quickly." So here's hoping this'll spur some improvement on my end. Cheers guys, love the content.
I'm a novice solver, so this was a great lesson on x-wings. My problem so far is that I know what to look for... sort of... but then I miss all the logic, because I'm not attentive enough. Gotta practice more :) So far, I'm following all your classic sudokus and anti-knight, it's my favourite!
I was able to finish at 26:17, and only had to watch about 9 minutes of the video to understand the x-wings enough to complete the puzzle! That felt very fast and exciting, ha, especially since I’ve never heard of x-wings!
Holy X-Wings indeed batman. This puzzle almost feels like a Math test where the entire point is to make sure you understand whatever the teacher just went over in class. In this case, thanks very much Sam for taking us to school on X-Wings, I think I counted 6 of them in this puzzle... Absolutely bonkers!
This is awesome. I had just figured out how this works after thinking about it for a long time...but this was top notch demonstratation by example. I would love to see more videos of a soduku getting solved by the application of one advanced idea.
I came back to try this again after failing at it a few weeks ago. Now that I know a bit more about the techniques involved I was able to complete it on my own. It still took me 45m and a couple of screw-ups, though. One thing this puzzle has made me realize is that Snyder notation makes spotting fish difficult. Since they are candidate elimination techniques, not seeing all the candidates on the board really slows things down. Even knowing what I was supposed to look for, it was a challenge. Ironically, I found the 6 and 9 swordfish easier to find than the 8 x-wing.
Thank You two so much for this channel! I’ve been searching the web so long for good an challenging Sudokus. Your Software and Apps are just great! I can’t wait what else you‘ll release in the future. Keep going like this.
I got a few numbers and then realised the centre square was a 6 or 8. I tried an 8 and it nearly worked. Then tried a 6 and I finished the puzzle...enjoyed this one...tnx.
Wow! First time i was succesful finding "advanced" tactics. I found 4 x-wings, and 1 3-row X-wing (which probably has a better name). Three of which actually resulted in progress. Lovely puzzle. Gonna watch the video to see how to do it more efficient as i did it in 27:11.
Looks like i did it exactly the same :) EDIT: Oh wait, i remember i got the 8 initially different. I pencilmarked 8s in r1c2 and r1c3 due to normal sudoku. Then i spotted 8s in row 4, 6 and 8, in columns 3, 6 and 7 ruling it out from r1c3. I guess the x-wing would've been easier (saw it later, but by then it didn't accomplish anything anymore for me).
12:22 The title of the video primed me to look for X-Wings (I found three in all); still, that's about a good a job as I've done finding such things as I ever have. EDIT: After watching the video … yep, found the same ones Mark did.
I used 4 different swordfish and jellyfish on this puzzle; now's when I find out the easier way. I need to look better at both orientations of the grid There was a neat checkerboard pattern on 9s
@@Orynae Are you're familiar with the concept of an x-wing? An x-wing involves 2 rows and 2 columns (4 squares total). A swordfish is the same logic, except its 3 rows and 3 columns, for up to 9 squares involves. Jellyfish is 4 and 4. It's all the same class of logic, the community just gives funny names when it gets bigger.
So if I understand correctly, an X wing is when a digit can only go in two columns in a row and in only in the same two columns in another row (or vice versa), whereafter you can rule out that digit from being anywhere else along those columns? Sorry if this is a dumb question, only recently found the channel/got into sudoku so I don’t have a lot of experience/knowledge yet
Close enough (same idea for columns as well). The next question you really need to answer is when do you start looking for one. Those guys just see them without really looking :-).
@@remigregoire2219 My favorite way: color all the cells where a digit can go, everywhere. Scan for repeated instances of the same cells in different rows/columns. Sometimes it jumps at you like that. You might want to also look at their "slot machine" technique videos, which is a more advanced take on this same highlighting idea.
The best explanation I have seen in youtube is from a guy named Sudoku Swami. Look for it. It may be a little bit slow, but he explains it very clearly.
I saw a good reason to color the x-wings, and keep them colored for a while. One may inadvertently pencil in a number the x-wing has ruled out. I saw a bent triple (249) ruined by the third digit. I decided to color it anyway. After dealing with the X-wings, sure enough, the third digit was removed and I could exploit the bent triple.
Great video, usually I find the X-wings the other way around (deducting that only those 4 can be a certain number). Purchased the app, which is really great, especially the keyboar shortcuts to achieve notations etc.
Excellent explanation of X-Wing. The puzzle unraveled nicely and slowly after those 1st 2 (I even did it too quickly and got an error at some point and had to back it up to those X wings and unravel slowly, lol) SUPER COOL 😅😎☕🎶
A month makes a difference. I'm replaying this. My first encounter was a finned X-wing in 2s which eliminated a candidate 2, probably uselessly. My second was a swordfish in 6s. I think that I spotted the same bent triple, but nothing fixed it this time. I didn't need it.
28:26 hell of a puzzle for me...guess i missed something obvious in the beginning... spotted a stockfish on 6s and some sort of a jellyfish though before i managed to see the required x-wings...nevertheless i cracked it ;)
I didn’t use x wings but solved in about 16 minutes, kept looking for them but never saw them ! I’m now trying to remember where I went right ! Nice puzzle I am wondering if someone has been confined to the basement
I didn't spot any x-wings, but my method was a lot slower (about 45 mins). But now I think it's crazy that there were so many x-wings and I didn't notice any when I solved it.
Interesting that he used the first 2 x wings to allow him to place sixes and eights at the top and then pencilled them in in 3 positions on either side having just ruled them out of column 5.
Thanks for this very clear X-wing lesson! I do wonder though... when you finished the two first x-wings you instantly after added pencil marks (in row 5) for 8's and 6's respectively, right in the way for the X-wings that ruled out those numbers from those cells in row 5. It felt a bit contradictory for me, not having used this technique ever yet in a puzzle. But otherwise, I had no problems keeping up with your thinking here and I think I get this X-wing now. Just need to learn to use it myself too. :-)
Yes, being expert speed solvers, their focus usually jumps around quickly, and they're often loose and sloppy with their pencil markings as a result. Not like us plebs plodding along still trying to work out the basics.
Can you please explain your logic used in deducing the 35 pair at 9:00? When I look at the board, possible 4's can be in R1C7, R1C9, and R3C7. Thank you!
This is called a naked pair or naked double. If you look at only the 3s and the 5s, you'll see that they can only go into those 2 squares. Since we only have two places for two numbers nothing else can go into those two squares, thus the 4 and 7 must go on the other side. You can imagine putting a 4 into one of the 35 squares, but then you'd see that you run out of room in that box, as there are no longer enough squares to place the 3 and the 5.
This was really cool! I’ve played sudoku for a while but I’ve never seen any sudoku videos or tried to learn any tricks from online. I’m definitely subscribing :D
i don't get the x wing at 8m30s. The 9 wasn't guaranteed to be in any of them. e.g top let could have been a 2, top right the 4, bottom left the 6 and bottom right the 7 or 8
X-wings aren't about what other numbers can go in those cells. The X-wing on 9s, if you look at colums 2 and 8 and try to see where 9s can go in those columns you will see both rows 2 and 9 match up to make an X-wing. 9s are limited to only those possible spots in those columns.
I don't know why this bothers me, but why would he pencil mark 8 and 6 in the center row after literally just proving there cant be any more 8s and 6s in that row because of the two x-wings?
You learn the logic of the various patterns involved, and practice spotting them. Over time they will become ingrained and you will get faster. I recently discovered the Hodoku java applet, and it has a training mode that covers all of the common patterns. It's a neat program, very complex. And although it doesn't support Snyder notation directly, you can highlight candidates in different colors with it. I'm also slowly working my way through the Sudoku Swami's video tutorial series. They can be tediously repetitive, and he has a bit of an attitude about him, but he does lay everything out in detail, with copious examples.
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I’ve never been able to understand X-wings until this video. What a great tool. Thanks!
It's funny I never understood what an x-wing is and even tutorials didn't help, mainly because most of them are in English.
He just colours one in and talks about it and I instantly got whats meant. Now I'm annoyed at myself that I didn't understand something so obvious.
Thank you very much.
I didn't use the X-Wing, instead I used the crank-handle pattern (as Simon calls it) between columns 2 and 8 for the 8's. The crank handle pattern immediately gives a 6 in column 5 and then you just have to watch the sudoku fall apart. It felt wonderful getting it, my first crank-handle :D
15:29 good to know I've still got it. The last few puzzles I tried from this channel took me multiple hours, with hints
such a satisfying puzzle to see unfold. been trying to up my classic game lately and I think this video will prove extremely helpful-- not just for the x-wing tip (brilliantly demonstrated btw), but the way Mark scans and asks the question "where can a x go in this row/column?" is just something that often evades me while i'm solving. there were a few times early in the video where I thought to myself "I wouldn't have spotted that nearly that quickly." So here's hoping this'll spur some improvement on my end. Cheers guys, love the content.
I'm a novice solver, so this was a great lesson on x-wings. My problem so far is that I know what to look for... sort of... but then I miss all the logic, because I'm not attentive enough. Gotta practice more :) So far, I'm following all your classic sudokus and anti-knight, it's my favourite!
I'm new to Sudoku, just finished this at 48:23
I was able to finish at 26:17, and only had to watch about 9 minutes of the video to understand the x-wings enough to complete the puzzle! That felt very fast and exciting, ha, especially since I’ve never heard of x-wings!
Holy X-Wings indeed batman. This puzzle almost feels like a Math test where the entire point is to make sure you understand whatever the teacher just went over in class. In this case, thanks very much Sam for taking us to school on X-Wings, I think I counted 6 of them in this puzzle... Absolutely bonkers!
This is awesome. I had just figured out how this works after thinking about it for a long time...but this was top notch demonstratation by example. I would love to see more videos of a soduku getting solved by the application of one advanced idea.
I came back to try this again after failing at it a few weeks ago. Now that I know a bit more about the techniques involved I was able to complete it on my own. It still took me 45m and a couple of screw-ups, though.
One thing this puzzle has made me realize is that Snyder notation makes spotting fish difficult. Since they are candidate elimination techniques, not seeing all the candidates on the board really slows things down. Even knowing what I was supposed to look for, it was a challenge.
Ironically, I found the 6 and 9 swordfish easier to find than the 8 x-wing.
I very much enjoyed solving this a few days ago! The multiple X-Wings were such a delight.
30:54 I don't know any tricks, such as "x-wings". I just do the puzzles. Maybe that's why I'm slow. So, I'll watch the dang video.
Those x-wings are very handy. There's actually three x-wings in it with fours but the fours doesn't help unfortunately.
@@RealCadde The 4 x-wing helped me solve the 2 in column 7 a bit faster, but wasn't necessary to solve the puzzle.
Thank You two so much for this channel! I’ve been searching the web so long for good an challenging Sudokus. Your Software and Apps are just great! I can’t wait what else you‘ll release in the future. Keep going like this.
The X-wings have found a weakness in this Death Star puzzle!
May the forced sollution be with you :)
23:37 for me. Might have been longer if not for the title of the video
Tried solving it first before watching the video, I got stuck because I didn't know X-Wings. This is really cool!
I got a few numbers and then realised the centre square was a 6 or 8. I tried an 8 and it nearly worked. Then tried a 6 and I finished the puzzle...enjoyed this one...tnx.
Wow! First time i was succesful finding "advanced" tactics. I found 4 x-wings, and 1 3-row X-wing (which probably has a better name). Three of which actually resulted in progress. Lovely puzzle. Gonna watch the video to see how to do it more efficient as i did it in 27:11.
Looks like i did it exactly the same :) EDIT: Oh wait, i remember i got the 8 initially different. I pencilmarked 8s in r1c2 and r1c3 due to normal sudoku. Then i spotted 8s in row 4, 6 and 8, in columns 3, 6 and 7 ruling it out from r1c3. I guess the x-wing would've been easier (saw it later, but by then it didn't accomplish anything anymore for me).
12:22 The title of the video primed me to look for X-Wings (I found three in all); still, that's about a good a job as I've done finding such things as I ever have.
EDIT: After watching the video … yep, found the same ones Mark did.
It took me pretty much the same time but I didn't find any X wings, even though I was constantly looking for them
I didn't look at the title and found three swordfishes instead.
Somehow I couldn't find a single X-wing, but I managed to find a jellyfish on 9s.
I used 4 different swordfish and jellyfish on this puzzle; now's when I find out the easier way. I need to look better at both orientations of the grid
There was a neat checkerboard pattern on 9s
I feel you, guess we solved the puzzle by using similar and overcomplicated routes ;)
Same thing here. I spotted the 9's jellyfish on rows 2,4,6,8 and that placed the 9 in row 1... as opposed to the x wing...
Another here 👌
What are swordfish and jellyfish?
@@Orynae Are you're familiar with the concept of an x-wing? An x-wing involves 2 rows and 2 columns (4 squares total). A swordfish is the same logic, except its 3 rows and 3 columns, for up to 9 squares involves. Jellyfish is 4 and 4. It's all the same class of logic, the community just gives funny names when it gets bigger.
So if I understand correctly, an X wing is when a digit can only go in two columns in a row and in only in the same two columns in another row (or vice versa), whereafter you can rule out that digit from being anywhere else along those columns? Sorry if this is a dumb question, only recently found the channel/got into sudoku so I don’t have a lot of experience/knowledge yet
Yes.
Close enough (same idea for columns as well). The next question you really need to answer is when do you start looking for one. Those guys just see them without really looking :-).
@@remigregoire2219 My favorite way: color all the cells where a digit can go, everywhere. Scan for repeated instances of the same cells in different rows/columns. Sometimes it jumps at you like that. You might want to also look at their "slot machine" technique videos, which is a more advanced take on this same highlighting idea.
The best explanation I have seen in youtube is from a guy named Sudoku Swami. Look for it. It may be a little bit slow, but he explains it very clearly.
I saw a good reason to color the x-wings, and keep them colored for a while. One may inadvertently pencil in a number the x-wing has ruled out.
I saw a bent triple (249) ruined by the third digit. I decided to color it anyway. After dealing with the X-wings, sure enough, the third digit was removed and I could exploit the bent triple.
I _have_ been having trouble with x-wings, and that did really help.
Great video, usually I find the X-wings the other way around (deducting that only those 4 can be a certain number). Purchased the app, which is really great, especially the keyboar shortcuts to achieve notations etc.
Excellent explanation of X-Wing.
The puzzle unraveled nicely and slowly after those 1st 2
(I even did it too quickly and got an error at some point and had to back it up to those X wings and unravel slowly, lol)
SUPER COOL
😅😎☕🎶
Lovely. The chain of x-wings was very amusing.
Brilliant puzzle and great video - file under X-wing spotting!
A month makes a difference. I'm replaying this. My first encounter was a finned X-wing in 2s which eliminated a candidate 2, probably uselessly. My second was a swordfish in 6s. I think that I spotted the same bent triple, but nothing fixed it this time. I didn't need it.
13:28 for me. Funny that you say X-wings. I found three separate swordfishes.
28:26 hell of a puzzle for me...guess i missed something obvious in the beginning... spotted a stockfish on 6s and some sort of a jellyfish though before i managed to see the required x-wings...nevertheless i cracked it ;)
alkz0r stockfish is a chess engine. You probably mean swordfish!
@@freddiehand6551 haha yes... guess i watch too much chess lately because its the only sport with regular coverage at the moment
I learned so much in this video. Thank you!!!
Thanks for providing interesting "classic" sudokus.
thank you for this - i tried this one last night and pulled my hair out trying to figure out those pairs in Column 5
I didn’t use x wings but solved in about 16 minutes, kept looking for them but never saw them !
I’m now trying to remember where I went right !
Nice puzzle
I am wondering if someone has been confined to the basement
I didn't spot any x-wings, but my method was a lot slower (about 45 mins).
But now I think it's crazy that there were so many x-wings and I didn't notice any when I solved it.
Another classic sudoku by Sam.
Interesting that he used the first 2 x wings to allow him to place sixes and eights at the top and then pencilled them in in 3 positions on either side having just ruled them out of column 5.
I almost thought I was the only one to notice
Great solve Mark!!
Had a slow time but once I got it I was very impressed! I used 5 X-Wings and a Swordfish
The X-ring are absolutely fantastic.
37:02 Got stuck, came back to find Marks X wing on the 8, then found many other x wings and got the solve.
11:54, wasn't too difficult. i like them when they're like this
i solved it before the video, i didnt really know how xwings worked. that kinda blew my mind and would have made it much easier
This is the only video you would ever need to watch in order to understand X-wings.
19:31. Damn what a layout
The most heartbreaking thing is accidentally navigating away from the page after almost solving it.... T_T
41:36. Found all the X wings down the two rows.
Thank you for this!!
Thanks for this very clear X-wing lesson! I do wonder though... when you finished the two first x-wings you instantly after added pencil marks (in row 5) for 8's and 6's respectively, right in the way for the X-wings that ruled out those numbers from those cells in row 5. It felt a bit contradictory for me, not having used this technique ever yet in a puzzle. But otherwise, I had no problems keeping up with your thinking here and I think I get this X-wing now. Just need to learn to use it myself too.
:-)
Yes, being expert speed solvers, their focus usually jumps around quickly, and they're often loose and sloppy with their pencil markings as a result. Not like us plebs plodding along still trying to work out the basics.
57:59
clearly, I've a long way to go.
X Wings and Quadruples are soooo easy to see....once it's pointed out to me!
Can you please explain your logic used in deducing the 35 pair at 9:00? When I look at the board, possible 4's can be in R1C7, R1C9, and R3C7. Thank you!
Common sense dude
This is called a naked pair or naked double. If you look at only the 3s and the 5s, you'll see that they can only go into those 2 squares. Since we only have two places for two numbers nothing else can go into those two squares, thus the 4 and 7 must go on the other side. You can imagine putting a 4 into one of the 35 squares, but then you'd see that you run out of room in that box, as there are no longer enough squares to place the 3 and the 5.
@@TheBlazers68 yeah it totally makes sense to me now. Don't know why it didn't earlier. Anyways, thanks for clarifying that up for me.
16:12 Now I will watch video to leartn what X-wing is
Love the videos!!
Our puzzle difficulty can't repel X-Wings of that magnitude!
When I click the link I am unable to multi-select using the shift key, which I used to be able to do. Any ideas please? Great video BTW.
What is the name of the music that your title cards are set to?
Mozart, and the opportunity of another sudoku! th-cam.com/video/rKni4EgjQ2M/w-d-xo.html
I was anticipating Mark's discovery of the fourth x-wing on fours in the same columns. Unfortunately he overwrote them using different logic.
This was really cool! I’ve played sudoku for a while but I’ve never seen any sudoku videos or tried to learn any tricks from online. I’m definitely subscribing :D
13.30
ty for the puzzle
wow, i'm not really good took me 42:52
Nice.
i don't get the x wing at 8m30s. The 9 wasn't guaranteed to be in any of them. e.g top let could have been a 2, top right the 4, bottom left the 6 and bottom right the 7 or 8
X-wings aren't about what other numbers can go in those cells.
The X-wing on 9s, if you look at colums 2 and 8 and try to see where 9s can go in those columns you will see both rows 2 and 9 match up to make an X-wing.
9s are limited to only those possible spots in those columns.
BEST
7:27!
I don't know why this bothers me, but why would he pencil mark 8 and 6 in the center row after literally just proving there cant be any more 8s and 6s in that row because of the two x-wings?
I wonder if Tom Collyer would do this in 2 min? no disrespect to Mark but Tom is just X wing Guru
12:31
i didn't find the x-wing on the 9's because i didn't do the proper x-wing on 6's, so i resorted to bifurcation, i found the other 3 x-wings tho
Nice bro
How to learn how to speed solve please
You learn the logic of the various patterns involved, and practice spotting them. Over time they will become ingrained and you will get faster.
I recently discovered the Hodoku java applet, and it has a training mode that covers all of the common patterns. It's a neat program, very complex. And although it doesn't support Snyder notation directly, you can highlight candidates in different colors with it.
I'm also slowly working my way through the Sudoku Swami's video tutorial series. They can be tediously repetitive, and he has a bit of an attitude about him, but he does lay everything out in detail, with copious examples.
@@davidh.4944 thank youuu
No wonder I had such an issue with this puzzle!! It’s horribly complicated!!
Haha, I just watched the older video on how to find X Wings
i have a sudoku that already spent 3 hours on it without a solution. Can i send it to this channel or anyone can help me solve it?
12:07 my time. First time "beating the video" it helped that the title gave away that I was looking for xwings so started searching for them early
P.S. A lesser solver would have been able to spot at least one more x-wing :-).
Yep that's me - with the 4's
@@dczzzz55 At a boy, or however that's spelled :-)
Four X-wings, and I spotted ONE on my own, which wasn't even useful at the point I discovered it! Ugh. This one made me feel blind
I quit here: i.postimg.cc/Z59DJSZr/Sudoku.png
If X-wings are the name of the game, then they're doing a bad job of showing themselves.
Six months later and I've finally solved it! 1:23:11 was my time.
How to learn how to speed solve please