📕Get my FREE Solving Guide that will help you solve over 80% of all Sudoku puzzles🧩to include NYT Hard👉👉www.buymeacoffee.com/timberlakeB/e/125822 Timestamps 0:00 Intro 00:18 It’s Solving Time 01:21 Puzzle Story 03:34 BONUS Tip 04:00 Question Of The Day 04:21 Setting Up Amazing Trick 08:30 Amazing Trick Revealed
Anyone can solve these. My extreme puzzle record is under 1:51. I think you are going into it too much as a seasoned player with thousands of solves can just memorize everything as they go so you don't have to lay down those "possible numbers". You just memorize it.
I was able to determine the '7' in the center block by process of elimination because a '5' and a '7' belong in the middle section of the top middle block but in either row 2, column 4 or row 2 column 6. Tough puzzle indeed and your method is indeed one (1) solution. I used brute force and started trying a '2' and or a '1' and was eventually able to solve.
As someone who never really knew how to play sudoku this video was amazing, such an elegant and logical way to solve what looks like a very complicated puzzle
@@HPSwimmingly - Because none of the 1, 2, 3 combinations worked, therefore the only square with only one extra digit (9) had to be the 9. (the others were 1, 2, 3, 4, 9. Right around 08:22 in that area.
It took me 46 minutes to solve this one. It take some time to master and to fix those techniques. I can say that one thing that is really helps me solve is the possibility to make corner and center notes, also paint the blocks. Now im feeling more confident to solve extreme puzzles. Thank you very much to share!!!!
I didn't mean to watch the whole video but it mesmerized me 😂 I kinda do the same when I have a lot of triplets and it seems suspicious when one of the cells has the same three options plus one additional option, I would try different options and eventually grew to choose the 'extra' first but I haven't used it as a proven method until now. Thanks!
@@SmartHobbies can't tell for sure, I tried the easy ones as a kid and then have been in and out doing this ever since :) so, 20+ years but not continuously 🔢
something that ive found doing these is there is always that key number that once you get it placed right the rest of the puzzle solves so much easier. sudoku is one of the funnest puzzles ive played really shows the connection numbers have. thanks for this
That was kinda cool. That 9 broke the puzzle open. I ended up with more 23 pairs than I should have had and then colored those and and realized I missed some. The colors made it stand out nicely. Even in standard sudoku like this, colors often help. Thanks.
Thanks for the tip !!! I’ll have to practice this. Sometimes in the “extreme” puzzles I just get stuck for extra time. I suspect seeing these triples and using colors it will speed up my otherwise confusing “trial-and-error” similar strategy.
I am new to Sudoku but I certainly love the challenge. Is there somewhere where I can find a website that has all the features you use in your TH-cam videos? Thank you for your insights, entertainment and thought provoking videos.
You are welcome Sir Thomas. If you want a desktop app that allows you to create puzzles with specific strategies in them and also has a help page explaining the strategies, I recommend Hodoku (through sourceforge.net). I did most of my early videos with this app and learned so much. My favorite web pages for advanced strategies are Sudokuwiki and taupier.
I paused the video and tried different strategies unsuccessfully. I was stuck. Thank you for your answer. I know a Sudoku must have only 1 solution. It has helped me solve other puzzles with 3 pairs of 2 digits and 1 pair with a 3rd digit added (in the right arrangement, such as a rectangle). I then know the 3rd digit is the correct one, otherwise the puzzle would have 2 solutions. But now I know it works with 3 digits and a 4th digit added in one of the cells (in the right arrangement). In the example case, the puzzle would not be solvable unless the 4th digit was placed.
My wife loved Sudoku, but whenever she got stuck on one I'd tell her I had the perfect solution. Tear the page out of the book, fold it into a paper airplane, open the window and let it escape out the window.
Nice one. I had spotted the 123s in all these squares, but yeah chasing a contradiction like that is super powerful. This 9 unlocks everything. There's one point where numbers are in a quadruplet on a line in the top squares, then solving the rest is pretty easy with pairs and triplets.
At 4:10, I fill in all the outside boxes with the remaining possible numbers. Then I resume doing the puzzle just as you started, until I hit another stopping point.
At around 5:24, right before you were preparing to highlight all the 1,2,3 boxes (and eventually the what if scenario with the 1,2,3, 9 box). I noticed that in vertical column 7 there are 3 squares that contain only the numbers 1, 2 and/or 3. This quickly identifies that the 1, 2, 3, 4 and 9 boxes can be reduced to only contain a 4 or a 9 in each box. While I like your method (and will incorporate it into my methodology), in this instance, I feel my identification was quicker. I'm looking forward to watching the rest of the video.
Ron, I have not followed your point yet. In column 7, Row 2 is a 1, 2 or 3. Row 4 is a 1, 2 or 3. Row 5 is a 1234 or 9. Row 6 is a 1234 or 9. Row 7 may be a 1 (or the 1 is in row 9 column 9). So, what can you conclude, what are the 3 squares with 1, 2, and/or 3? Rows 2 and 4, yes. But row 7 may be a 1, or the 1 may be row9, col9. So how can 123 be eliminated from the 12349 in rows 5 and 6? (If row 7, col7 is not 1 but row9, col9 is, then row7, col7 is essentially unlabeled at this stage, so what are the 3 squares in column 7 that must be a 1, 2 and/or 3?).
@@ttb1513 Hi. You are correct. As this was the first time I watched an online video for solving Sudoku, I wasn't familiar with the Snyder method. So when I saw the the three boxes in column 7 that contained only the numbers 1, 2, and/or 3, I jumped the gun in my analysis. The box with the 1 could have other possible numbers. If I had done it my normal method, I wouldn't have populated that field with just a 1. I didn't adjust for the method that you were teaching that was new to me.
I got to your 4 minute mark and had made an error with a 4/9 pair in block 6 row 7. Even if I hadn't done this I don't think I would have spotted that 9 move. Once I put the 9 in the correct place it quickly tumbled to successful completion, thank you.
I love this. In graph theory, what you did was prove that you needed 1 more than the max clique number of colors in order to chromatically color a vertex graph
I've been watching your channel, so I took the same path as you - except that I couldn't remember how a trivalue oddagon works after I recognized the pattern. I tried the whole branching sequence (there are 4 choices) of colour assignments before placing the 9. I was pretty sure that the odd-man-out had to break the pattern, but wanted to refresh my memory about the reasoning. I think that the computer solvers that actually look for patterns (rather than the ones that just Bowman's Bingo through the whole puzzle) will pretty soon start looking for Trivalue Oddagon/Thor's Hammer. It seems to be pretty popular with the setters lately. And then the human solvers will learn it - and a puzzle like this won't be Extreme any more.
I agree. I haven't run across any solvers yet that look for this, but I am sure I will soon. Great job solving this one. There is nothing wrong with running through all the variations again.
I had the same issue that Ke9tv had. I thought I remembered enough to give this puzzle a go, but got bogged down with multi-coloring all over the place. Solve time was almost 1 1/2 hours, not counting having to watch the video. I should know enough now to solve this type of puzzle next time, but with my memory, I doubt it.
i start my puzzles by going through the numbers in the least require order - twice , as a lot can change after the first pass through , then like you i proceed with the 9 boxes with the least required or the rows and columns least required , but also its good say when you have just 3 numbers in row or column to watch out where the other numbers cannot go from the one needed to complete them .
I always do the puzzle before I see the solve. I did it a little different from you I alternated the colors on the 123 tripples. The box where you solved the 9 had 123 see all of the three colors thus elimanating them also makinking the 9, Also the box in r7 c7 seen all three colors thus making that box also a 9.
You might want to name this as "THE EXTREME X-WING" or "THE SUPER X-WING" Solution ! These always give me a headache, but I have learned to solve these "knots", too! Thanks.
That's a really interesting pattern. So you can't really have triplets arranged in a square/rectangle, such that they're all on individual rows/columns within each sector? At least one of them would have to break the pattern and have two in a single column or row? Is that it?
Sure Lenny. I am solving this puzzle in SudokuPad, though I have to load it into a desktop app called SudokuMaker first and then generate a solving link for it. Hope that helps.
How can I recognize these patterns? Like what if there were like "569" possibilites in say 3 blocks, should I take it as a sign that there's a pattern going on and like think about it this way? When does it become a pattern and not a coincidence? Thanks
Great question. Most Sudoku strategies can be spotted by looking for a pattern. For this particular strategy, the Trivalue Oddagon, you are comparing the 3 digits limitations of at least 4 blocks on the puzzles. Other extreme strategies have different patterns. How long have you been solving Sudoku?
4:10 - My strategy before finding solvers was to copy this into an excel spread sheet and when I got here, I would guess at one of the numbers with a different colour. I would keep guessing until I got a conflict then make the opposite guess when I went back from my last guess. then keep doing that until i solved it.
Check all the numbers from 1 to 9, and when you make a couple of entries, just start with 1 again. That's how I always did it. Sometimes I would check each square if it's getting boring. I'm by far not as fast as you are.
Thank you for sharing that. I find some benefit in knowing I’ve checked all digits vs the other method of scanning and solving all digits as you go. How long have you been solving Sudoku?
Your method may work for simple sudokus like this one but the way you're reasoning drops a lot of hints. My method is completely different. When I start the sudoku, I write 123456789 in each void square then I eliminate the numbers that are already showed in their squares, rows or columns. Now a very important thing: when a square is solved through that elimination process, I put it in memory and when I validate it, I also exclude that number from their square, row or column, and new solved square may appear in the process and are all put in memory. That way I'm sure that no information is forgotten. When that initial part of the solving ends, which means that there are no more solved squares to exploit, I start eliminating numbers thanks to patterns. And like in the previous step, I systematically exploit the consequences of each discovery. For example if I have 5 square with 145, 145, 145, 14589 and 14589, it become clear that both 14589 are actually 89 then I analyse the consequences of the elimination of 1, 4 and 5. Using that method, I'm sure that I used all the available information before being obliged to work on hypothesis.
Thank you for sharing your method with me and the other viewers. I like how you consider all the candidates and use your working memory to make eliminations and deductions.
I mostly put more than 2 notes, like 3-4 just so that I would have an idea of what can be found where. Then once I go through the digits, I try to look on what eliminates what. There is only 1 way to solve sudoku I guess. But most of the times, there are dilemmas, like parallels that I cannot solve and just have to go with one of 2 digits, and mostly I pick the wrong one
Fascinating. I never guessed the 1239 cell could be the key. I tried to solve using the interesting restrictions with column 5 as the axis and the miniX Wing of 5s. Came somwhat close, but in the end, a fail.
I haven't watched many videos on sudokus with all this terminology. I've realised that in a way this is what I do, but I don't do it with colours... I just say if this is say, a 3, then I see if logically it is possible by going through the other consequences.
13:00 - 🎶That's three in the corner That's three in the spotlight Losing it's religion 🎶 Gotta love both REM and Simon Anthony - always Cracking the Cryptic and saying "Bobbins"
The only games I have ever played on my phone is this. Completely addicted to it. The more complicated then better. My level of choice is called Diabolical 😅
at column 8 row 8 only option 2or3, this then lead to doublet above with 2 options, work through and then find correct solution. Mind you permutations are 2x 2 x2 ie factor 6 which is a lot, best use excel or other program and work through options, if no go then reverse changes and try other option. what do u think re this?
Wow. Now that's breaking it down . I like the mystery method of not sketching notes, and just .. doing it..often I make bobos gotta admit but I get more satisfaction anyway. Or so maybe now I'll try your method and spot the octagon
I found all the examples you started with. I paused at 4:03. I saw that I could mark 9s in the middle line of the the bottom centre and right blocks because of the 9s in the bottom left block and the 9 in the top right block. Similarly, I could mark 1s in the central column of the right top and right middle blocks because of the three empty squares of that column and the location of 1. That allowed me to mark the central square of the bottom right block. I then scanned the rows and columns with four empty squares, looking for the digits other than 1, 2, and 3 that go into that row. I repeated that for the other columns. I saw that I could mark column 5 rows 2 and 4 with 7. I could mark columns 3 and 5 row 6 with 6. That's as far as I got without writing anything down.
This is not a trick, this is a methodology. It was demonstrated on a medium hardship level. It is way more challenging solving a killer Soduko. For me, this methodology has been a natural solution and I am glad that somebody, finally showed me what I have been doing naturally, for years.
Here's another way: Once you filled enough with the vertical and horizontal strategy by number, you can have a strategy of 123456789 by horizontal and vertical ( which should apply to each line, either horizontal, either verical ), and for sure you'll find more numbers.
I like to play on paper, without tracking probable numbers; using the habit to improve memory. 1) I repeat the previous process at least once more 1-9; as by simply filling a number, it eliminates possibilities where there are just pairs to work with. 2) look to solve missing numbers in blocks where there are 4 or fewer numbers missing. 3) keep a close 3-way double-check on completed rows, columns, and blocks. Though only doing sudoku a few years, most news papers printed 5 star complex puzzles, I finish successfully in under 30 minutes. a long way from world record speeds; but my memory seems to improve some
4:06 i would either try to solve individual rows or columns or individual box with overlaping numbers to see if i can single out numbers example bottom middle box the two 4s have two 9s and the two 6s have two 7s than next to five is 3
this is basically how I've worked through sudoku for over 20 years (though I must admit sometimes I've given up due to the mental drain). With my puzzles, I draw a tic-tac-toe grid and place all the numbers still to be assigned in each section, and the missing numbers both horizontally and vertically still to be placed to either side, and either above or below, so I don't have to keep checking which I'm missing. Will try to remember this process. Often I get to a certain point then go "but there's two (insert number)s!"
Try drawing a grid 27 x 27. That way you have 81 squares and each one has 9 boxes, 3x3. Accent the lines that make the 9 inner cubes, then cross out all the horizontal, vertical, and individual box numbers, to see what remains.
@@david_cop_a_feel7538 this stuff is just to the side of a printed puzzle, I just do it to keep track of the numbers still needed, as drawing another entire sudoku grid seems a hell of a lot of work for something that's meant to be fun (I do also make the small numbers in each square till they're eliminated). besides, the whole thing is only a 9x9 grid, not 27x27
@@SmartHobbies this was the first of your videos that I watched, it popped up on my home page. I hadn't encountered the rectangle approach before and it as interesting to hear that there are terms for required numbers (I originally played sudoku on an Apple Mac in the 90s, it was a game called "Single Number" which I assumed was what sudoku means in Japanese)
Great question. There does have to be at least one other digit possibility in those groups of cells, but it could be more than one extra in one cell or multiple cells with extra digit, which doesn’t make the solve as straightforward as this.
An easier way of knowing that the 123 triples can't be correct, is that with 123 in each block, any arrangement of those numbers will work. Which means that the puzzle has more than 1 solution. Which is disallowed. The same thing happens with two numbers in a rectangle.
I can see where you are going, but I play paper copies only so have no way to "color" and change block colors. I end up writing every number possible in each box. Usually I keep going over things till I find the one numbet that I've missed that solves the puzzle. Often times I walk away too!
Wow. I balked at making 2 bifurcations with the coloring. And I didn't understand I should ask the question of whether R6C6 could be a 123 (or had to be a 9). But, with that focus, you can quickly make two bifurcations and eliminate the 4 possibilities and go, Oh, R6C6 is a 9! Then it solves easily. Thank you for advancing my logic ability. Very frustrating that I couldn't do this myself - I knew the techniques. It just didn't seem useful and I didn't see how to specifically apply them. Can R6C6 be a 123? Wasn't a question I asked, but that seems reasonable it retrospect. I figured the triples you referred to were the 123's. I tried several times to color them, but had to bifurcate them twice. I was hoping to eliminate certain bifurcations and advance my coloring a little bit.
For the tougher puzzles, you will have to also consider quadruples and even quintuples. My best approach is to complete 90% of the puzzle legitimately, then use probability to solve the remainder. This has worked 99% of the time for me.
@@SmartHobbies If I haven't solved the puzzle outright in 20 minutes, I look for a number that's in a double or triple combination in an aligned row or column. I'll take the number that's in the double, since it has a better chance of being correct. That said, I'm aware that there are people who are much smarter and can do the puzzle in much less time.
I use a simple pencil and eraser on the paper puzzle, so colors don't work. In looking for the initial solves I start with the number having the greatest initially appearing frequency, and solve where I can. If that number is not completely solved for all rows, columns and boxes, I mentally subdivide each cell into nine imaginary sub-cells, and write in that number (in very small print) in its proper position in those cells where that number is not solved or ruled out. I then repeat the process for the remaining numbers in descending order of initially appearing frequency. The reason for proceeding in descending order of frequency instead of numerical order (1, 2, 3 etc.) is that the more frequently appearing numbers are more likely to produce initial solves and thereby in turn make additional solves of the less frequently appearing numbers more likely. Each unsolved square will have all possible number solves written therein in small print. I can then proceed much as the video explains to solve the rest of the puzzle.
I was hoping to be able to color the 123's but I couldn't connect any of them outside of 1 box or one column, etc. I tried bifurcating the colors but still couldn't go very far and was looking at a second bifurcation, so I couldn't see how to fill in the coloring enough to use it.
Thank you for your comments and feedback. This was a tricky puzzle if you had not seen the logic before. Sounds like you added another strategy to your Sudoku solving toolkit. Keep it up!
Sir, at 10:15 or so you solve for a 7 in block 7. But that was solved when you put the 9 into block 8 instead of the 2-3 in block nine. Love what you do but that step was a little confusing.
Thank you for the feedback. You are right. That 7 could have been solved another way like using a pointing pair in block 8 that would have been less confusing. 👍🏻
I got to 14:03 and your "hope you didn't give up" made me keep ttrying.. I figured blocks 789 were key. I colorred all pottential 9s blue, noticced that a 9 inn r6c9 was very forcing and that gave everything simply (In other words, very lucky). Edit: Just finished watching annd II waas incrdibbly llucky. I had coloredd all potenntial 9s and the R6C9 stood out as highly forcing. Thhat this is thhe samme bllock tthe 123 trick hit wass reallyy ccool.. But obvioussly the 123 eliminatioon was far moore logical. Great concept.
Also known as not enough problems for the number of variables. Can solve an equation that has three variables only if you have three equations with three unknowns, or twelve equations with twelve unknowns.
Give up? I didn't dare to try it 😅 But after you solve the start and pencilmark the 123 I knew what was the trick! So I give it a try. Hehe It was nice puzzle and I had fun watching you too! ☺
Nice presentation, thank you. I’m still new at this, and not looking to be right, but rather NOT to be wrong! My sincerest apology upfront and of course please correct and/or redirect if I am mistaken/wrong or misunderstand your footage commentary; btw, I did turn on the subtitling, too! I truly wanna learn everything possible, especially from a creator like you and beat all those Evil/Expert/Beyond Advantage Sudoku. As I considered Sudoku to be a game of logic and a process of elimination, not a choice/guess, i.e. luck, here’s my question about: why are you ‘turning’ cell r6c9 (in block 6) into number “9”, other than calling it a ‘Trivalue Oddagon/Tragon’? 1. At 8:47, why are you saying “…you have to introduce another digit…, why ‘introduce…? 2. Doesn’t (r6c9) have already 4 penciled digits, i.e, #9 is already there as an option, so again why ‘introduce another digit’? 3. Is this because already 3 blocks have already 3 cells with 1,2,3, and a 4th blocks is “almost”(?!) similar. 4. Again my apologies if I sound confusing and assuming that you are making a choice/guess for (r6c9) to be a 9, but that is why I’m confused,😁, apparently. 5. Also, what is the minimum amount of blocks with a #,#,# pattern in a puzzle to apply a Trivalue Oddagon/Tragon scenario? Please if at all possible provide a more explicit and detailed explanation why a 9 in (r6c9). Look forward to hearing from you
Great questions. I am sure others who watched have similar concerns. 1. For Oddagon strategies like this, you are trying to avoid a situation that would break the puzzle (cause 2 of same digit in a house or no digits in a cell). So I first show what would happen if the highlighted cells contained just 3 separate digits (1,2,3). By showing the puzzle will break, I show that you have to "introduce" a 4th digit (the 9) to allow the puzzle to be solved. 2. Similar to 1, you first consider if a 9 is necessary in that cell by removing it and see what happens. 3. Yes. 4. No worries. 5. For Trivalue Oddagons, I have only seen these with 12 affected cells from 4 blocks. I would imagine that you could do this with 6 or possible 8 blocks and 18-24 cells but I have not seen that done. By contrast, Single value Oddagons only need 5 cells minimum. I recommend you check out my Oddagon Tutorial to get a more detailed explanation of Oddagons work: th-cam.com/video/Vf-HMsB00AI/w-d-xo.htmlsi=5eQW_L1b4UfyIJSO
@@6497raesame here. I have recently been using two different color pens for my dots (black & red). When there are only two possibilities in a 3x3 box for a particular number I do those dots in color. This speeds up my analysis and solving once I have all possibilities marked.
I’m not totally sure on the transitions from the colors into the solve. It looks like the colors (which was a neat exclusion strategy)… didn’t work, so we guessed a 9, and then continued as any normal player would do. Did I miss something?
You have the right idea. The colors show that no possible combination of just 3 distinct digits will satisfy the pattern of cells. You must introduce a 4th digit to avoid breaking the puzzle. Since the 9 is only available in one of the cells, it must be the solution. Hope that helps.
All these years playing Sudoku in apps and not being able to colour them was my problem. 😮😢 Ive tried to do similar things to work out future placements but limited to placing temp numbers or just full them in. It's easy to forget what you are doing and screw up your whole game and I just put it down to me being crap.
Thank you for your question. The puzzle link is in the description just below the initial paragraph. It works for desktop, tablet, or mobile. Merry Christmas 🎄
I like to use the gambler's method. You solve all the unambiguous cells then, choose one with lowest ambiguity, now you guess, then proceed to remainder of puzzle &... snap pencil 28 minutes later.
Thank you for sharing that Andrew. That is great to hear that you can solve your puzzle notation free. Where do you normally get the puzzles that you solve?
Great question. At that point of the solve, I noticed that after solving the 8, that there was only spot remaining to place the 6 in that block, so that has to be where the 6 goes in the block. Does that help?
Great question. The pattern of 123's is called a trivalue oddagon. It cannot be resolved by 3 candidates 123 alone, which is how I know to solve that cell for a 9. The idea is to solve the cell for a value in order to avoid a situation that would break the puzzle. Learn more about how Oddagons work here: th-cam.com/video/Vf-HMsB00AI/w-d-xo.htmlsi=_rTQvQcwzOm8SlbT
Great question. I solve the puzzles using SudokuPad which works on desktop or mobile. I load the puzzle in a free desktop app called Sudokumaker. Hope that helps.
When solving sudokus I don't put marks in blank squares. Instead I will identify a row or column and place the missing number outside the puzzle, close to an edge if I know the number has to go in the adjacent 3x3 or further away if I know it has to go in the middle 3x3. If I can identify the numbers that will occupy a corresponding number of squares but not the order in which they have to go in I will mark those squares with a dot in place of each missing number so I know which squares remain blank for the time being. It is only a partial strategy and won't work for a diabolical sudoku but I have identified a few sudoku puzzles that were presented as being diabolical which actually turned out to have logical links. In the puzzle shown, at the point where asked what to do next it is obvious that a 6 must occupy one of the three squares on the bottom line of the middle 3x3 so my next step would have been to place a "distant" 6 outside the puzzle indicating which row the 6 would have to be placed in. I'll stop there.
Cool idea. I’ve seen championship solvers place digits outside the grid like you described to help them work through the possibilities. Thank you for sharing. Do you normally solve with pencil and paper?
@@SmartHobbies Always. I'm not a fan of working on screens when puzzling. Besides, pen and paper is easier to use when lying in a bean bag. BTW I am impressed by the strategy you showed.
One of the first rules in learned in Sudoku is 'guess' is not allowed. Now when we assumed at first that the number '9' might not exist in the block which can include the numbers 1239, then aren't we making a guess? And when we arbitrarily assigned a color for each block, isn't this tantamount to assigning a figure and find out if it works? Why not assign a number if it works, to make it simpler if guess is permitted?
Great question. All Sudoku strategies are based upon recognizing patterns within a puzzle. These patterns create logical eliminations (for example, if 2 candidates are restricted to same 2 cells in a row, then no other candidates can be there and can safely be eliminated). The Tridagon is a large more complicated pattern that leads to specific logical eliminations every time. Once you spot the pattern, you can make those eliminations with certainty. Does that help?
@@SmartHobbies Your explanation makes sense, thanks. But I thought that logic must come first before any elimination. Though the elimination of the number 9 from the rest (123) turned out to be correct, what was the logic behind the elimination in the first place? Was it arbitrary?
This (4 min in) is where I finish penciling in all possibles for all open squares. (I admit this may be a bad idea, but I eventually solve them all, so it is what I have stayed with.) Then I go on, look for patterns that force conclusions, yada.
Start with the number 1? Naw. Start with the number you have the most of and any singular spaces that can rule out lots of numbers that were possibilities and narrow it down. Ruling out is preferable to ruling in. If you can get the same two potentials in that row, you can move on to the numbers remaining, since you know those two are no longer included for the rest of the row or boxed group. Also look to see if a number has been in a center box yet, (it's infrequent that a number is used twice in a center box). So much faster!
At 4:10 one would know that 9 is only possible in the 7:7 and 9:9 squares, and consequently 2 and 3 being the only possibilities in columns 8 and 9 on row 8. Hence, on the same row, column 3 would be a 7 and column 7 a 6. At the same time, one would know that row 7 in the middle block only could contain 3 or 4, and that row 9 in the same block only could contain 6 and 7.
Contrary to the video, I don’t record my hobby sudoku solving. Hence, I cannot go back and see what I did (or check the reasoning). If not apparent, then let’s not rule out that I made a mistake. That happens, and I stand corrected, should that be the case.
I think I need to start with "Sudoku 100" because I'm totally lost. I thought each number could only appear in the same location in ONE of the 9 square in each of the groups?
This is an advanced puzzles. You are correct that the digits 1-9 can only appear once in each 3x3 block. I use the app to mark the possible candidates in the center of each cell to help make eliminations. To build a solid Sudoku foundation, I recommend you check out my Beginner Tutorial playlist here: th-cam.com/play/PLfx5Lh2Tz0OhbighkgvI4oHYw47MlDlwX.html&si=pBcR5bKHa0JWOqgU
📕Get my FREE Solving Guide that will help you solve over 80% of all Sudoku puzzles🧩to include NYT Hard👉👉www.buymeacoffee.com/timberlakeB/e/125822
Timestamps
0:00 Intro
00:18 It’s Solving Time
01:21 Puzzle Story
03:34 BONUS Tip
04:00 Question Of The Day
04:21 Setting Up Amazing Trick
08:30 Amazing Trick Revealed
Anyone can solve these. My extreme puzzle record is under 1:51. I think you are going into it too much as a seasoned player with thousands of solves can just memorize everything as they go so you don't have to lay down those "possible numbers". You just memorize it.
I was able to determine the '7' in the center block by process of elimination because a '5' and a '7' belong in the middle section of the top middle block but in either row 2, column 4 or row 2 column 6.
Tough puzzle indeed and your method is indeed one (1) solution. I used brute force and started trying a '2' and or a '1' and was eventually able to solve.
I've doing this my whole life, I was expecting like a different trick hahaha, I guess this is the only way to solve these Sudokus
Nice. I guess it comes naturally to some people 😎
Same I too thought there was different technique
Isn't this just the same way we all solve every sudoku?
Nothing new here. Soduko is kind of... simple.
@@pgoof78 Simple, you say - with 3 spelling mistakes in the name already 😂 Just teasing 😉
As someone who never really knew how to play sudoku this video was amazing, such an elegant and logical way to solve what looks like a very complicated puzzle
Thank you for your kind words! I love teaching people about the logic behind Sudoku.
Your explanation is so good that we have absolutely NO idea how you got these partial answers.
Thank you! 😊 Merry Christmas. 🎄
Some people are so smart that they need a translator.
Yes some people might but if a teacher needs it, you just got a bad teacher.@@Bigfoot-px9gj
Agree, see my reply above.... still all a guess/luck to me, why (r6c9) is a 9?
@@HPSwimmingly - Because none of the 1, 2, 3 combinations worked, therefore the only square with only one extra digit (9) had to be the 9. (the others were 1, 2, 3, 4, 9. Right around 08:22 in that area.
It took me 46 minutes to solve this one. It take some time to master and to fix those techniques. I can say that one thing that is really helps me solve is the possibility to make corner and center notes, also paint the blocks. Now im feeling more confident to solve extreme puzzles. Thank you very much to share!!!!
You are welcome. Thank you so much for sharing your experience. I am glad you found it helpful!
Is there a particular Sudoku app that you prefer?
Thank your for that really clear explanation - I never thought of using colour blocks to show where a number couldn't be!
You are welcome Rosemary!
Thank you for teaching this trick. I love sudoku, and I'm able to solve most hard puzzles, but this trick is something I never saw before!
You are welcome, Lydia. Glad you found it helpful. 😊
Thanks. You explanation was crystal clear and totally logical. I'm not sure what others apparently found confusing.
Hmm... this seems so simple in the explanation. I guess I need to dig a little deeper into sudoku tricks. Thanks for sharing!
You are welcome.
Thanks for the trick. I had noticed all the 123's and highlighted them but never thought to use colours and solve for 9.
Awesome. You are well on your way to becoming a Sudoku expert. 👍🏻 Merry Christmas 🎄
This is an amazing 'trick'. Even the best online sudoku solvers do not have this one integrated. Kudos to you, sir, and thank you!
You are welcome. Glad you liked it 😊
I left it out over night & the next morning my daughter filled the missing boxes out with letters. (She is 5 so it’s a win for me:)
Nice!
That is adorable. I would save that one for sure.
I didn't mean to watch the whole video but it mesmerized me 😂
I kinda do the same when I have a lot of triplets and it seems suspicious when one of the cells has the same three options plus one additional option, I would try different options and eventually grew to choose the 'extra' first but I haven't used it as a proven method until now. Thanks!
You are welcome. Glad you liked it.
How long have you been solving Sudoku?
@@SmartHobbies can't tell for sure, I tried the easy ones as a kid and then have been in and out doing this ever since :) so, 20+ years but not continuously 🔢
something that ive found doing these is there is always that key number that once you get it placed right the rest of the puzzle solves so much easier. sudoku is one of the funnest puzzles ive played really shows the connection numbers have. thanks for this
Thanks for sharing. I agree that there is usually that one cell or digit that acts as a tipping point for the whole puzzle. 👍
That was kinda cool. That 9 broke the puzzle open.
I ended up with more 23 pairs than I should have had and then colored those and and realized I missed some. The colors made it stand out nicely. Even in standard sudoku like this, colors often help.
Thanks.
You are welcome! Glad you liked the video and the strategy. How often do you play Sudoku?
@@SmartHobbies A few a week.
@ Awesome. Me too. Keep it up! Merry Christmas. 🎄
How did he decide where to put that '9'?
Nice! The coloring part is the key. That works for PC or app easily, but not in paper form. 😁
Love these little brain exercises. Usually start as you did but then I do lines, then go to the boxes
Awesome!
Thanks for the tip !!! I’ll have to practice this. Sometimes in the “extreme” puzzles I just get stuck for extra time. I suspect seeing these triples and using colors it will speed up my otherwise confusing “trial-and-error” similar strategy.
You are welcome. Keep it up. Merry Christmas 🎄
That was one fun video to watch. Absolutely loved it.
I am glad you enjoyed it!
I am new to Sudoku but I certainly love the challenge.
Is there somewhere where I can find a website that has all the features you use in your TH-cam videos?
Thank you for your insights, entertainment and thought provoking videos.
You are welcome Sir Thomas. If you want a desktop app that allows you to create puzzles with specific strategies in them and also has a help page explaining the strategies, I recommend Hodoku (through sourceforge.net). I did most of my early videos with this app and learned so much.
My favorite web pages for advanced strategies are Sudokuwiki and taupier.
I paused the video and tried different strategies unsuccessfully. I was stuck. Thank you for your answer. I know a Sudoku must have only 1 solution. It has helped me solve other puzzles with 3 pairs of 2 digits and 1 pair with a 3rd digit added (in the right arrangement, such as a rectangle). I then know the 3rd digit is the correct one, otherwise the puzzle would have 2 solutions. But now I know it works with 3 digits and a 4th digit added in one of the cells (in the right arrangement). In the example case, the puzzle would not be solvable unless the 4th digit was placed.
Forgot to add THANK YOU! I appreciate you and the lesson.
You are welcome, Michele. I like how you worked out the logic of this puzzle in your comment. Keep it up!👍
My wife loved Sudoku, but whenever she got stuck on one I'd tell her I had the perfect solution. Tear the page out of the book, fold it into a paper airplane, open the window and let it escape out the window.
I think that’s a great solution. Haha.
😀 When I get stuck, I pause the game, and walk away. When I come back, I nearly always can spot a couple more easily, and maybe even finish. Weird.
Lol
@@PeterLawton i tried that method at work and got fired...
People who make things like this are the reason why sometimes non sociopath people have to get away with murder ... 😂😂😂
Nice one.
I had spotted the 123s in all these squares, but yeah chasing a contradiction like that is super powerful.
This 9 unlocks everything.
There's one point where numbers are in a quadruplet on a line in the top squares, then solving the rest is pretty easy with pairs and triplets.
Nice observation, Fred. Thank you for sharing. 👍🏻
At 4:10, I fill in all the outside boxes with the remaining possible numbers. Then I resume doing the puzzle just as you started, until I hit another stopping point.
In other words, I proceed just as you did…
Thank you for sharing your feedback. Happy to hear that we solve similarly. Had you seen this solving trick before?
At around 5:24, right before you were preparing to highlight all the 1,2,3 boxes (and eventually the what if scenario with the 1,2,3, 9 box). I noticed that in vertical column 7 there are 3 squares that contain only the numbers 1, 2 and/or 3. This quickly identifies that the 1, 2, 3, 4 and 9 boxes can be reduced to only contain a 4 or a 9 in each box. While I like your method (and will incorporate it into my methodology), in this instance, I feel my identification was quicker. I'm looking forward to watching the rest of the video.
Nice job looking at that column, Ron. Thank you for sharing your approach. Merry Christmas 🎁🎄
Ron, I have not followed your point yet. In column 7,
Row 2 is a 1, 2 or 3.
Row 4 is a 1, 2 or 3.
Row 5 is a 1234 or 9.
Row 6 is a 1234 or 9.
Row 7 may be a 1 (or the 1 is in row 9 column 9).
So, what can you conclude, what are the 3 squares with 1, 2, and/or 3?
Rows 2 and 4, yes. But row 7 may be a 1, or the 1 may be row9, col9.
So how can 123 be eliminated from the 12349 in rows 5 and 6?
(If row 7, col7 is not 1 but row9, col9 is, then row7, col7 is essentially unlabeled at this stage, so what are the 3 squares in column 7 that must be a 1, 2 and/or 3?).
@@ttb1513 Hi. You are correct. As this was the first time I watched an online video for solving Sudoku, I wasn't familiar with the Snyder method. So when I saw the the three boxes in column 7 that contained only the numbers 1, 2, and/or 3, I jumped the gun in my analysis. The box with the 1 could have other possible numbers. If I had done it my normal method, I wouldn't have populated that field with just a 1. I didn't adjust for the method that you were teaching that was new to me.
@@ronparent1063 Ok. Thanks for confirming. I learned from this analysis, and was wondering if I was correct.
@@ronparent1063 his explanations are ... casual.
I got to your 4 minute mark and had made an error with a 4/9 pair in block 6 row 7. Even if I hadn't done this I don't think I would have spotted that 9 move. Once I put the 9 in the correct place it quickly tumbled to successful completion, thank you.
You are welcome, Dominic. I am glad to hear that you found this video helpful. How often do you solve Sudoku puzzles?
I love this. In graph theory, what you did was prove that you needed 1 more than the max clique number of colors in order to chromatically color a vertex graph
Awesome! Thank you for sharing that connection to graph theory. Do you teach?
I've been watching your channel, so I took the same path as you - except that I couldn't remember how a trivalue oddagon works after I recognized the pattern. I tried the whole branching sequence (there are 4 choices) of colour assignments before placing the 9. I was pretty sure that the odd-man-out had to break the pattern, but wanted to refresh my memory about the reasoning.
I think that the computer solvers that actually look for patterns (rather than the ones that just Bowman's Bingo through the whole puzzle) will pretty soon start looking for Trivalue Oddagon/Thor's Hammer. It seems to be pretty popular with the setters lately. And then the human solvers will learn it - and a puzzle like this won't be Extreme any more.
I agree. I haven't run across any solvers yet that look for this, but I am sure I will soon. Great job solving this one. There is nothing wrong with running through all the variations again.
I had the same issue that Ke9tv had. I thought I remembered enough to give this puzzle a go, but got bogged down with multi-coloring all over the place. Solve time was almost 1 1/2 hours, not counting having to watch the video. I should know enough now to solve this type of puzzle next time, but with my memory, I doubt it.
Such a clear demonstration! Thank you.
You are welcome! 😊
i start my puzzles by going through the numbers in the least require order - twice , as a lot can change after the first pass through , then like you i proceed with the 9 boxes with the least required or the rows and columns least required , but also its good say when you have just 3 numbers in row or column to watch out where the other numbers cannot go from the one needed to complete them .
I admire your technique, Alex. Thank you for sharing.
I always do the puzzle before I see the solve. I did it a little different from you I alternated the colors on the 123 tripples. The box where you solved the 9 had 123 see all of the three colors thus elimanating them also makinking the 9, Also the box in r7 c7 seen all three colors thus making that box also a 9.
Nice job! Thank you for sharing your technique.😀
You might want to name this as "THE EXTREME X-WING" or "THE SUPER X-WING" Solution ! These always give me a headache, but I have learned to solve these "knots", too! Thanks.
You are welcome. Thank you for the name suggestion. 👍🏻
That's a really interesting pattern.
So you can't really have triplets arranged in a square/rectangle, such that they're all on individual rows/columns within each sector? At least one of them would have to break the pattern and have two in a single column or row? Is that it?
You got it!
Brilliant trick - thanks! Can you please tell me which sudoko software you are using for this video?
Sure Lenny. I am solving this puzzle in SudokuPad, though I have to load it into a desktop app called SudokuMaker first and then generate a solving link for it. Hope that helps.
@@SmartHobbies ❤ Appreciated.
How can I recognize these patterns? Like what if there were like "569" possibilites in say 3 blocks, should I take it as a sign that there's a pattern going on and like think about it this way? When does it become a pattern and not a coincidence? Thanks
Great question. Most Sudoku strategies can be spotted by looking for a pattern. For this particular strategy, the Trivalue Oddagon, you are comparing the 3 digits limitations of at least 4 blocks on the puzzles. Other extreme strategies have different patterns.
How long have you been solving Sudoku?
4:10 - My strategy before finding solvers was to copy this into an excel spread sheet and when I got here, I would guess at one of the numbers with a different colour. I would keep guessing until I got a conflict then make the opposite guess when I went back from my last guess. then keep doing that until i solved it.
That is one way to do it. Thank you for sharing.
love the trick. will watch for it. any set of four 'connected' triples can never support 3 digits
Nice. I hope you do!
Great trick, can't wait to try it out!!!
Check all the numbers from 1 to 9, and when you make a couple of entries,
just start with 1 again. That's how I always did it.
Sometimes I would check each square if it's getting boring.
I'm by far not as fast as you are.
Thank you for sharing that. I find some benefit in knowing I’ve checked all digits vs the other method of scanning and solving all digits as you go. How long have you been solving Sudoku?
Your method may work for simple sudokus like this one but the way you're reasoning drops a lot of hints. My method is completely different. When I start the sudoku, I write 123456789 in each void square then I eliminate the numbers that are already showed in their squares, rows or columns. Now a very important thing: when a square is solved through that elimination process, I put it in memory and when I validate it, I also exclude that number from their square, row or column, and new solved square may appear in the process and are all put in memory. That way I'm sure that no information is forgotten. When that initial part of the solving ends, which means that there are no more solved squares to exploit, I start eliminating numbers thanks to patterns. And like in the previous step, I systematically exploit the consequences of each discovery. For example if I have 5 square with 145, 145, 145, 14589 and 14589, it become clear that both 14589 are actually 89 then I analyse the consequences of the elimination of 1, 4 and 5. Using that method, I'm sure that I used all the available information before being obliged to work on hypothesis.
Thank you for sharing your method with me and the other viewers. I like how you consider all the candidates and use your working memory to make eliminations and deductions.
I mostly put more than 2 notes, like 3-4 just so that I would have an idea of what can be found where. Then once I go through the digits, I try to look on what eliminates what. There is only 1 way to solve sudoku I guess. But most of the times, there are dilemmas, like parallels that I cannot solve and just have to go with one of 2 digits, and mostly I pick the wrong one
Fascinating. I never guessed the 1239 cell could be the key. I tried to solve using the interesting restrictions with column 5 as the axis and the miniX Wing of 5s. Came somwhat close, but in the end, a fail.
So close, Georges! The logic was a little tricky to put together.
I haven't watched many videos on sudokus with all this terminology. I've realised that in a way this is what I do, but I don't do it with colours... I just say if this is say, a 3, then I see if logically it is possible by going through the other consequences.
Thank you for sharing, Bassbarbie. I hope you check out more Sudoku videos and learn some more terminology. 😎
The shift to color codes is genius.
Thank you Luke!
Great trick, thanks! One question: does it always work or do I have to do the color coding to check that it is the correct setup?
It will always work with the pattern of 4 blocks and the triple cells are in different rows/columns in the blocks.
13:00 -
🎶That's three in the corner
That's three in the spotlight
Losing it's religion 🎶
Gotta love both REM and Simon Anthony - always Cracking the Cryptic and saying "Bobbins"
The only games I have ever played on my phone is this. Completely addicted to it. The more complicated then better. My level of choice is called Diabolical 😅
I love that you play Sudoku daily. Thank you for sharing.
at column 8 row 8 only option 2or3, this then lead to doublet above with 2 options, work through and then find correct solution. Mind you permutations are 2x 2 x2 ie factor 6 which is a lot, best use excel or other program and work through options, if no go then reverse changes and try other option.
what do u think re this?
6 factorial is 720 possible options, obviously only one will be correct
Wow. Now that's breaking it down . I like the mystery method of not sketching notes, and just .. doing it..often I make bobos gotta admit but I get more satisfaction anyway. Or so maybe now I'll try your method and spot the octagon
I hope you do, Wendy, and thank you for sharing your perspective.
Do you normally solve with pencil and paper?
@SmartHobbies Im a beginner. I use online suds and word games, mainly because newspapers aren't really available here. SJ Mercury, and nyt games.
❤ Sudoku - this is a fantastic solve 👍👍👍
Thank you! Cheers!
I found all the examples you started with. I paused at 4:03. I saw that I could mark 9s in the middle line of the the bottom centre and right blocks because of the 9s in the bottom left block and the 9 in the top right block. Similarly, I could mark 1s in the central column of the right top and right middle blocks because of the three empty squares of that column and the location of 1. That allowed me to mark the central square of the bottom right block. I then scanned the rows and columns with four empty squares, looking for the digits other than 1, 2, and 3 that go into that row. I repeated that for the other columns. I saw that I could mark column 5 rows 2 and 4 with 7. I could mark columns 3 and 5 row 6 with 6.
That's as far as I got without writing anything down.
instead of colours could you just use xy and z? to form your tri value oddagon? just a thought
You could do that with pencil and paper. Some people add letters as corner marks to do the logic. Thank you for sharing. 😀
This is not a trick, this is a methodology. It was demonstrated on a medium hardship level. It is way more challenging solving a killer Soduko. For me, this methodology has been a natural solution and I am glad that somebody, finally showed me what I have been doing naturally, for years.
Thank you for your feedback. Do you prefer to solve Killer Sudoku?
Little Jack Horner
Sat in a corner
Eating his Christmas pie
He put in his thumb
Then pulled out a plum
And said what a clever clogs am I ?
Here's another way:
Once you filled enough with the vertical and horizontal strategy by number, you can have a strategy of 123456789 by horizontal and vertical ( which should apply to each line, either horizontal, either verical ), and for sure you'll find more numbers.
👍
I like to play on paper, without tracking probable numbers; using the habit to improve memory.
1) I repeat the previous process at least once more 1-9; as by simply filling a number, it eliminates possibilities where there are just pairs to work with.
2) look to solve missing numbers in blocks where there are 4 or fewer numbers missing.
3) keep a close 3-way double-check on completed rows, columns, and blocks.
Though only doing sudoku a few years, most news papers printed 5 star complex puzzles, I finish successfully in under 30 minutes.
a long way from world record speeds; but my memory seems to improve some
Nice Daniel. I like your process. Thank you for sharing. Keep it up.
4:06 i would either try to solve individual rows or columns or individual box with overlaping numbers to see if i can single out numbers example bottom middle box the two 4s have two 9s and the two 6s have two 7s than next to five is 3
Nice technique. Thank you so much for sharing.
this is basically how I've worked through sudoku for over 20 years (though I must admit sometimes I've given up due to the mental drain). With my puzzles, I draw a tic-tac-toe grid and place all the numbers still to be assigned in each section, and the missing numbers both horizontally and vertically still to be placed to either side, and either above or below, so I don't have to keep checking which I'm missing. Will try to remember this process. Often I get to a certain point then go "but there's two (insert number)s!"
Thank you for watching and for sharing your approach. How long have you been watching the channel?
Try drawing a grid 27 x 27. That way you have 81 squares and each one has 9 boxes, 3x3. Accent the lines that make the 9 inner cubes, then cross out all the horizontal, vertical, and individual box numbers, to see what remains.
@@david_cop_a_feel7538 this stuff is just to the side of a printed puzzle, I just do it to keep track of the numbers still needed, as drawing another entire sudoku grid seems a hell of a lot of work for something that's meant to be fun (I do also make the small numbers in each square till they're eliminated). besides, the whole thing is only a 9x9 grid, not 27x27
@@SmartHobbies this was the first of your videos that I watched, it popped up on my home page. I hadn't encountered the rectangle approach before and it as interesting to hear that there are terms for required numbers (I originally played sudoku on an Apple Mac in the 90s, it was a game called "Single Number" which I assumed was what sudoku means in Japanese)
@ Cool!
You made it look easy
wow .... that was good, thank you!
Glad you liked it!
But does that fourth extraneous digit always happen? So we can always solve for the "extra" one?
Great question. There does have to be at least one other digit possibility in those groups of cells, but it could be more than one extra in one cell or multiple cells with extra digit, which doesn’t make the solve as straightforward as this.
An easier way of knowing that the 123 triples can't be correct, is that with 123 in each block, any arrangement of those numbers will work. Which means that the puzzle has more than 1 solution. Which is disallowed. The same thing happens with two numbers in a rectangle.
You make a great point, Corwyn. Oddagon patterns like this require that a puzzle has 1 unique solution. Thank you for sharing.
I can see where you are going, but I play paper copies only so have no way to "color" and change block colors. I end up writing every number possible in each box. Usually I keep going over things till I find the one numbet that I've missed that solves the puzzle. Often times I walk away too!
Thank you for sharing your approach. Sometimes I have to walk away as well:)
Wow. I balked at making 2 bifurcations with the coloring. And I didn't understand I should ask the question of whether R6C6 could be a 123 (or had to be a 9). But, with that focus, you can quickly make two bifurcations and eliminate the 4 possibilities and go, Oh, R6C6 is a 9! Then it solves easily. Thank you for advancing my logic ability. Very frustrating that I couldn't do this myself - I knew the techniques. It just didn't seem useful and I didn't see how to specifically apply them. Can R6C6 be a 123? Wasn't a question I asked, but that seems reasonable it retrospect. I figured the triples you referred to were the 123's. I tried several times to color them, but had to bifurcate them twice. I was hoping to eliminate certain bifurcations and advance my coloring a little bit.
. By filling in the 3 colors in the boxes 1,3,and 4, the 9 in box 6 couldn’t be colored and all the other 123 boxes could be colored as well.
Nice. Thank you for figuring that out and sharing. 😎
For the tougher puzzles, you will have to also consider quadruples and even quintuples. My best approach is to complete 90% of the puzzle legitimately, then use probability to solve the remainder. This has worked 99% of the time for me.
Thank you for sharing your approach, William. How long are you willing to spend on a puzzle before resorting to probability?
@@SmartHobbies If I haven't solved the puzzle outright in 20 minutes, I look for a number that's in a double or triple combination in an aligned row or column. I'll take the number that's in the double, since it has a better chance of being correct. That said, I'm aware that there are people who are much smarter and can do the puzzle in much less time.
@@williamstraub3844 That seems like a solid approach. Thank you for sharing.
Outstanding!
Thank you so much! 😊
Great stuff
Glad you liked it.😎
I use a simple pencil and eraser on the paper puzzle, so colors don't work. In looking for the initial solves I start with the number having the greatest initially appearing frequency, and solve where I can. If that number is not completely solved for all rows, columns and boxes, I mentally subdivide each cell into nine imaginary sub-cells, and write in that number (in very small print) in its proper position in those cells where that number is not solved or ruled out. I then repeat the process for the remaining numbers in descending order of initially appearing frequency. The reason for proceeding in descending order of frequency instead of numerical order (1, 2, 3 etc.) is that the more frequently appearing numbers are more likely to produce initial solves and thereby in turn make additional solves of the less frequently appearing numbers more likely. Each unsolved square will have all possible number solves written therein in small print. I can then proceed much as the video explains to solve the rest of the puzzle.
Oh wow. I have not heard of doing the marking by frequency before. Thats pretty cool. Thanks for sharing.
I was waiting for the trick. It's my usual procedure.
Thank you for watching and for your feedback, Peter. Have you seen these trivalue oddagons before?
I was hoping to be able to color the 123's but I couldn't connect any of them outside of 1 box or one column, etc. I tried bifurcating the colors but still couldn't go very far and was looking at a second bifurcation, so I couldn't see how to fill in the coloring enough to use it.
Thank you for your comments and feedback. This was a tricky puzzle if you had not seen the logic before. Sounds like you added another strategy to your Sudoku solving toolkit. Keep it up!
Sir, at 10:15 or so you solve for a 7 in block 7. But that was solved when you put the 9 into block 8 instead of the 2-3 in block nine. Love what you do but that step was a little confusing.
Thank you for the feedback. You are right. That 7 could have been solved another way like using a pointing pair in block 8 that would have been less confusing. 👍🏻
Kinda reminds me of BUG+1 (Bi-value Universal Graveyard).
Maybe we could call it a TUG+1?
I got to 14:03 and your "hope you didn't give up" made me keep ttrying.. I figured blocks 789 were key. I colorred all pottential 9s blue, noticced that a 9 inn r6c9 was very forcing and that gave everything simply (In other words, very lucky). Edit: Just finished watching annd II waas incrdibbly llucky. I had coloredd all potenntial 9s and the R6C9 stood out as highly forcing. Thhat this is thhe samme bllock tthe 123 trick hit wass reallyy ccool.. But obvioussly the 123 eliminatioon was far moore logical. Great concept.
Awesome, Tony. I'm glad you didn't give up. It is cool that you focused on the correct cell to get the solve. Thank you for sharing.😀
Also known as not enough problems for the number of variables. Can solve an equation that has three variables only if you have three equations with three unknowns, or twelve equations with twelve unknowns.
You make a good point, Kelly. Thank you for sharing.
Give up? I didn't dare to try it 😅
But after you solve the start and pencilmark the 123 I knew what was the trick! So I give it a try. Hehe
It was nice puzzle and I had fun watching you too! ☺
Nice presentation, thank you. I’m still new at this, and not looking to be right, but rather NOT to be wrong!
My sincerest apology upfront and of course please correct and/or redirect if I am mistaken/wrong or misunderstand your footage commentary; btw, I did turn on the subtitling, too!
I truly wanna learn everything possible, especially from a creator like you and beat all those Evil/Expert/Beyond Advantage Sudoku.
As I considered Sudoku to be a game of logic and a process of elimination, not a choice/guess, i.e. luck, here’s my question about: why are you ‘turning’ cell r6c9 (in block 6) into number “9”, other than calling it a ‘Trivalue Oddagon/Tragon’?
1. At 8:47, why are you saying “…you have to introduce another digit…, why ‘introduce…?
2. Doesn’t (r6c9) have already 4 penciled digits, i.e, #9 is already there as an option, so again why ‘introduce another digit’?
3. Is this because already 3 blocks have already 3 cells with 1,2,3, and a 4th blocks is “almost”(?!) similar.
4. Again my apologies if I sound confusing and assuming that you are making a choice/guess for (r6c9) to be a 9, but that is why I’m confused,😁, apparently.
5. Also, what is the minimum amount of blocks with a #,#,# pattern in a puzzle to apply a Trivalue Oddagon/Tragon scenario?
Please if at all possible provide a more explicit and detailed explanation why a 9 in (r6c9).
Look forward to hearing from you
Great questions. I am sure others who watched have similar concerns.
1. For Oddagon strategies like this, you are trying to avoid a situation that would break the puzzle (cause 2 of same digit in a house or no digits in a cell). So I first show what would happen if the highlighted cells contained just 3 separate digits (1,2,3). By showing the puzzle will break, I show that you have to "introduce" a 4th digit (the 9) to allow the puzzle to be solved.
2. Similar to 1, you first consider if a 9 is necessary in that cell by removing it and see what happens.
3. Yes.
4. No worries.
5. For Trivalue Oddagons, I have only seen these with 12 affected cells from 4 blocks. I would imagine that you could do this with 6 or possible 8 blocks and 18-24 cells but I have not seen that done. By contrast, Single value Oddagons only need 5 cells minimum.
I recommend you check out my Oddagon Tutorial to get a more detailed explanation of Oddagons work: th-cam.com/video/Vf-HMsB00AI/w-d-xo.htmlsi=5eQW_L1b4UfyIJSO
It's always satisfying to watch humans beat computational algorithms!
It’s easier to make notes by using the dot method, where you just mark dots if a number is present in every 9x9 square.
Nice! Thank you for sharing the dot method. I need to try that with my pencil solving.
I've used the dot method for years. Not sure how else anyone can solve them!
@@6497raesame here. I have recently been using two different color pens for my dots (black & red). When there are only two possibilities in a 3x3 box for a particular number I do those dots in color. This speeds up my analysis and solving once I have all possibilities marked.
Came to learn Sudoku, ended up mastering it.
Awesome to hear that. Do you prefer Classic Sudoku or variant rule sets?
I’m not totally sure on the transitions from the colors into the solve. It looks like the colors (which was a neat exclusion strategy)… didn’t work, so we guessed a 9, and then continued as any normal player would do. Did I miss something?
You have the right idea. The colors show that no possible combination of just 3 distinct digits will satisfy the pattern of cells. You must introduce a 4th digit to avoid breaking the puzzle. Since the 9 is only available in one of the cells, it must be the solution. Hope that helps.
All these years playing Sudoku in apps and not being able to colour them was my problem. 😮😢
Ive tried to do similar things to work out future placements but limited to placing temp numbers or just full them in. It's easy to forget what you are doing and screw up your whole game and I just put it down to me being crap.
I am glad you realized that you are better at this than you thought. Keep it up. Colouring can help with many hard puzzles.
wheres the link to try myself before i watch your vid ? or have i got to draw it on paper ?
Thank you for your question. The puzzle link is in the description just below the initial paragraph. It works for desktop, tablet, or mobile. Merry Christmas 🎄
I like to use the gambler's method. You solve all the unambiguous cells then, choose one with lowest ambiguity, now you guess, then proceed to remainder of puzzle &... snap pencil 28 minutes later.
As soon as he said "two fours", all us Canadians had our attention span fly out the window.
😎
@@SmartHobbies 🍻 🍻🍻
I never use notation. I think it makes it to easy.
Thank you for sharing that Andrew. That is great to hear that you can solve your puzzle notation free.
Where do you normally get the puzzles that you solve?
I think you missed a 9 - bottom right in the middle right hand block on your first round.
Thank you for pointing that out. You got a sharp eye 👍
3:15 right bottom square You put 6 (after filling 8). But that place is valid for 9 too. So how can You be sure, that 6 is correct? Lucky guess?
Great question. At that point of the solve, I noticed that after solving the 8, that there was only spot remaining to place the 6 in that block, so that has to be where the 6 goes in the block. Does that help?
@@SmartHobbies Yeah, you are right. Thanks.
9:09 How can you be sure that it has to be a 9? Or did you just decide to make it a 9? (In which case the sudoku has several correct solutions?)
Great question. The pattern of 123's is called a trivalue oddagon. It cannot be resolved by 3 candidates 123 alone, which is how I know to solve that cell for a 9. The idea is to solve the cell for a value in order to avoid a situation that would break the puzzle. Learn more about how Oddagons work here: th-cam.com/video/Vf-HMsB00AI/w-d-xo.htmlsi=_rTQvQcwzOm8SlbT
What software are you using? Like the name of the Sudoku app…
Great question. I solve the puzzles using SudokuPad which works on desktop or mobile. I load the puzzle in a free desktop app called Sudokumaker. Hope that helps.
When solving sudokus I don't put marks in blank squares. Instead I will identify a row or column and place the missing number outside the puzzle, close to an edge if I know the number has to go in the adjacent 3x3 or further away if I know it has to go in the middle 3x3. If I can identify the numbers that will occupy a corresponding number of squares but not the order in which they have to go in I will mark those squares with a dot in place of each missing number so I know which squares remain blank for the time being. It is only a partial strategy and won't work for a diabolical sudoku but I have identified a few sudoku puzzles that were presented as being diabolical which actually turned out to have logical links.
In the puzzle shown, at the point where asked what to do next it is obvious that a 6 must occupy one of the three squares on the bottom line of the middle 3x3 so my next step would have been to place a "distant" 6 outside the puzzle indicating which row the 6 would have to be placed in. I'll stop there.
Cool idea. I’ve seen championship solvers place digits outside the grid like you described to help them work through the possibilities. Thank you for sharing.
Do you normally solve with pencil and paper?
@@SmartHobbies Always. I'm not a fan of working on screens when puzzling. Besides, pen and paper is easier to use when lying in a bean bag. BTW I am impressed by the strategy you showed.
@ Thank you for sharing. Glad to hear it. 😎
thats great
Box 9 can only be 123 also. You can save a lot of time.
Thank you for pointing that out.
One of the first rules in learned in Sudoku is 'guess' is not allowed.
Now when we assumed at first that the number '9' might not exist in the block which can include the numbers 1239, then aren't we making a guess? And when we arbitrarily assigned a color for each block, isn't this tantamount to assigning a figure and find out if it works? Why not assign a number if it works, to make it simpler if guess is permitted?
Great question. All Sudoku strategies are based upon recognizing patterns within a puzzle. These patterns create logical eliminations (for example, if 2 candidates are restricted to same 2 cells in a row, then no other candidates can be there and can safely be eliminated). The Tridagon is a large more complicated pattern that leads to specific logical eliminations every time. Once you spot the pattern, you can make those eliminations with certainty. Does that help?
@@SmartHobbies Your explanation makes sense, thanks. But I thought that logic must come first before any elimination. Though the elimination of the number 9 from the rest (123) turned out to be correct, what was the logic behind the elimination in the first place? Was it arbitrary?
could neither find trivalue oktagon nor chromatic pattern.
I am sorry to hear that. It can be tricky to spot. Did you get a chance to watch the video?
@@SmartHobbies yep i did. and it worked. i just wanted to read up on the used method but couldnt find it.
This (4 min in) is where I finish penciling in all possibles for all open squares. (I admit this may be a bad idea, but I eventually solve them all, so it is what I have stayed with.) Then I go on, look for patterns that force conclusions, yada.
Makes sense to me. Thank you for sharing your method. 👍🏻
Duh, this is what I do. This just confimed my way of thinking and doing Sudoku.
Start with the number 1? Naw. Start with the number you have the most of and any singular spaces that can rule out lots of numbers that were possibilities and narrow it down. Ruling out is preferable to ruling in. If you can get the same two potentials in that row, you can move on to the numbers remaining, since you know those two are no longer included for the rest of the row or boxed group. Also look to see if a number has been in a center box yet, (it's infrequent that a number is used twice in a center box). So much faster!
Thanks for sharing. I like that you look for the most popular digit first. 👍🏻
My computer solver states that the starting grid has more than one solution or that guessing is required, and marks it as invalid.
Sometimes you might get that if the solver is not able to solve it or if a digit is not in the right place when you input them.
At 4:10 one would know that 9 is only possible in the 7:7 and 9:9 squares, and consequently 2 and 3 being the only possibilities in columns 8 and 9 on row 8. Hence, on the same row, column 3 would be a 7 and column 7 a 6. At the same time, one would know that row 7 in the middle block only could contain 3 or 4, and that row 9 in the same block only could contain 6 and 7.
Help me see how you eliminated the 9 in row 8 column 9?
Contrary to the video, I don’t record my hobby sudoku solving. Hence, I cannot go back and see what I did (or check the reasoning). If not apparent, then let’s not rule out that I made a mistake. That happens, and I stand corrected, should that be the case.
I think I need to start with "Sudoku 100" because I'm totally lost. I thought each number could only appear in the same location in ONE of the 9 square in each of the groups?
This is an advanced puzzles. You are correct that the digits 1-9 can only appear once in each 3x3 block. I use the app to mark the possible candidates in the center of each cell to help make eliminations.
To build a solid Sudoku foundation, I recommend you check out my Beginner Tutorial playlist here: th-cam.com/play/PLfx5Lh2Tz0OhbighkgvI4oHYw47MlDlwX.html&si=pBcR5bKHa0JWOqgU