📕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 00:21 It’s Solving Time 00:40 Puzzle Story 01:56 BONUS Tip 04:30 What To Do After Snyder Done 04:55 Surprising Intermediate Strategy #1 06:36 Searching For Single Candidate Strategies 10:40 Surprising Intermediate Strategy #2 15:00 Setting Up Powerful Strategy 18:24 Powerful Strategy Revealed 23:00 Following The Snyder
Thank you very much Timberlake, that is such a great puzzle ! I did it again on paper one day after your explanations and I manage to crack it, not exactly like you but I found the Xwings, the pointing pairs and after worked with finding Xchain ☺ Thank you because that is this level I like to exercise to improve ☺ Best regards. Françoise
I did it last night, and had to sleep right after. What I remember: three or four X-wings, a Y-wing, and a "nice continuous loop"? I still had to bifurcate. 0:40 That 8? Placed early as my first digit. My second digit was far later -- a 3 in the corner if I recall correctly. (BTW, a TH-cam video has a song about 3 in the corner.) 4:40 Your question: shortly before I reached that point, while I was still cornermarking 8s, I found and applied an X-wing in 8s -- rows 1 and 9. At your point in the grid, I found the X-wing in 4s -- columns 1 and 9. Then I centermarked a few blocks, and tried finding restricted cells, to minimal success. I returned to centermarking blocks. The next feature was a 567 triple in column 3. 5:10 I found that 249 triple backwards: instead, I found the 1567 quad in row 3. (It chopped five-digit cells down to two or three digits.) One interesting feature that wasn't useful in itself: the four corners were all bivalued cells, X9 -- 9 and some other digit. 7:00 I found the X-wing in 2s before finding the 1567 quad. It was my third X-wing. And now, I noticed something I missed in my solve: two of the cells -- R5C1 and R5C9 -- were common to both the 2 and 4 X-wings. That gave a 24 pair that I missed, due to clutter. 11:10 You never saw that before? It appeared a couple times on CtC, where I first learned it. I once saw three swordfish that shared the same cells in a column. That gave a triple. 11:50 Because I didn't think of the 24 pair, I didn't get the 3 until a 259 Y-wing. 12:40 The 6s were my final X-wing, the 8s were my first X-wing, and like 24, I didn't get the 68 pair. 16:50 Again, I found the 34 pair backwards: I saw the 567 triple first. 19:10 The Y-wing that I found was completely different: 259 in columns 1 and 2. It gave me the 3 in the corner and removed a bunch of 9s. Video's END: I found this loop, which I believe is a form of "nice continuous loop": rows 2 and 9, columns 1 and 9. Counterclockwise from R9C9: 59, 19, 12, 25. Because of everything I missed, I still bifurcated. About clutter: centermarking the grid lets me find positions that I usually would otherwise miss. The disadvantage: I miss things.
Thank you very much Timberlake, that is such a great puzzle ! I did it again on paper one day after your explanations and I manage to crack it. Thank you so much because that is the level I like to exercise . Best regards. Françoise
I find this type of puzzle layout difficult. I didn't see any clue as when to pull off basic Snydering and start coloring single candidates, so I just kept filling in possibly restricted cells until it appeared no longer useful. Then I started coloring single candidates and found x-wings. But there is no good way to notate cells that have been eliminated using x-wings, so I fill in all the other cells in the block with the candidate (using corner marking), which eliminates the usefulness of Snyder. So then the board was very cluttered and I wasn't able to remember which x-wings overlapped. Total puzzle solve time, 1:42, not counting time watching the video or filling out the comment.
At the point in the solve that you asked about I noticed BVC's in the corners, then looked for (and thought I found) a swordfish on ones that eliminated 1 from r3c5. ThIs gave me a great boost on completing r1, r9, c1 & c9... until a conflict on 4's popped up at the extremities of the middle row. Then I came back hoping to learn where I had taken a wrong turn... and learned a new XY trick, and learned that I need to study swordfishes (yet again). Thanks for another nice video.
Ive been doing sudoku in Freeform(that one drawing app) for a bit now, but now I’ve gotten good at all variants of column restriction eliminations-xwing, swordfish, jellyfish kraken etc. I manually highlight the candidate num and start from the highest going down, and eliminate possible rows for usage if they don’t align with any others up to whatever number of columns it’s restricted to. I’ve actually gotten very quick at doing this, but the slow thing for me is filling in all candidates in the cells and doing the highlighting. Is there some app that has features like this? Or perhaps even an app that will make all solves restricted to certain strategies so you can focus on weaknesses?
I am so happy to hear about your progress. I like to use Hodoku desktop app to pre-fill candidates and use their practice and learning modes to create puzzles with specific strategies. Here is a link to my tutorial where I show you how to do both easily: th-cam.com/video/QCVOSevcYoI/w-d-xo.htmlsi=tlOX8K5NsB6ODJkC
What a beautiful puzzle and a real joy. I loved all the different techniques needed. I saw it differently from how you did- I saw the naked quad first, and same for the triple into the 34. For a reason unknown, I didn’t see the XY wing in the usual way. Early on I recognised the corner cells were BV cells, and that at least one must contain a 9. It was clearly an unintended solve path and sent me on some long, complicated adventures 😂 ultimately I saw it as rings on R1C1/ R1C9/ R9C1/ R9C9 and R1C2/ R1C8/ R9C2/ R9C8, with some eliminations possible, after all the lovely x-wings first of course. I wish I’d have unfolded the story of it in the intended way though, just fabulous sudoku creation. One to save to my favourites.
A war of attrition, but a fun one. Anything but a notation-free quickie. The overlapping X-Wings were most satisfying. My version of HoDoKu rates the puzzle as Unfair rather than Hard, but with the same score. Intriguingly, the broken symmetry might be made symmetrical with only the slightest tweak, yielding a puzzle of very similar difficulty and a near-identical solution path: 001 204 500 004 090 060 800 000 003 100 009 005 009 000 600
After seeing all the restrictions you marked with snyder notions, I saw the X Wings of 2s and 4s in columns 1 and 9 (which cause 24s to be a pair in r5c1+9. and then the X Wings of 6 and 8 in rows 1 and 9 (which cause 68 to be a pair in r1+9c5.. Then the clear certainty is that the 3 must be in r1c1. Then I completed the puzzle and as everything seemed to work well, I ended up with a mistake of 2s and 5s only in blocks 5 and 6. I know my mistake originated in block 1. I need to review what I did wrong there. I suspect now that a 5 must be in r9c1 I placed it in r2c1, and hebce a 9 in r9c1
This is a tough one! Thank you for showing the techniques. You illustrated how to locate the X wings by highlighting the cells where 2 (in this particular example) could be placed. Is this the best way to find an X wings by highlighting all the possible cells? Is it faster than putting in notations in all the cells? I need to find an app that would allow me to do such highlighting if that is the most efficient way. Thank you!
Great question, Kenneth. I find it easier to see when highlighting all the cells. Hodoku on desktop does it quickly by clicking on the digit filters at the top, and you can use SudokuPad to do it manually via desktop or mobile. I do not know of any phone app that does candidate highlighting. If you find one, please share with the rest of us. With paper and pencil, I focus on conjugate pair restrictions for specific candidates and then compare rows or columns to find X-Wings, skyscrapers, 2-string kites, empty rectangles, finned X-Wings, etc. Hope that helps.
@@SmartHobbies Thank you so much for your reply! I downloaded SudokuPad. Is it true that this app does not erase the same number in related cells when you input a correct number? Either it’s my old age or there is a bug in the program because when I put in a correct number, it gave me the message of it being wrong. I checked this number over several times and I did not make a mistake!
@@kennethmiu691 you can turn on conflict checker in the settings and you should see numbers turn red when you put 2 of the same digit in a house. You can also select in settings whether to remove or keep pencil markings after you solve a cell. I am not sure why it is telling you a digit is wrong when it should not be.
@@SmartHobbies Great! Thank you again for the pointers. I will definitely re-set the controls. The coloring and the hint in the one I just solved were very useful, allowing me to learn more about the techniques. Thank you!
@@SmartHobbiesI remember getting x wings on 2,4,6,8. Got 68 pair in col 5 ( due to overlapping of 6/8 x wings) I think in row 5 , instead of writing 24 pair, i wrote 234 on one end at R5C1 and 24 on the other end at R5C9. Got row3 with 1567 quad and also 34 pair in col3, pointing 7's in top row of box 3. I used a diff loop involving cols 1 and 9, rows 2 and 9 ( 12-->19-->59-->25) but that helped me to get rid of just one 5 at R8C1. Bla bla... Then I sneaked into ur video to complete the puzzle. Great puzzle indeed.
Great question. I have several people come to my channel through my beginner and intermediate tutorials. I run through the basics to try and bridge the gap between basic and more advanced strategies. Are there particular strategies or difficulty level you would like to see, Michael?
6:16 How is square 35 & 36 a pointing pair of 1's when square 26 & 36 can also be a pair of 1's? And 37 can also be a 1. So far I am not seeing how any of this is helpful. But I am looking at a grid where all of the helper bits are being shown. I'll keep watching.
I misspoke about the 1s being a pointing pair there. Once the hidden triple is revealed, they are just Snyder 1’s with 2 spots remaining in each block. I apologize for the confusion. Thank you for pointing that out.
📕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
00:21 It’s Solving Time
00:40 Puzzle Story
01:56 BONUS Tip
04:30 What To Do After Snyder Done
04:55 Surprising Intermediate Strategy #1
06:36 Searching For Single Candidate Strategies
10:40 Surprising Intermediate Strategy #2
15:00 Setting Up Powerful Strategy
18:24 Powerful Strategy Revealed
23:00 Following The Snyder
Your solve was absolutely phenomenal. All the wings founded were amazing. Thanks for that! 😊
Glad you liked it Ana. I thought this was a phenomenal puzzle. 🧩
Thank you very much Timberlake, that is such a great puzzle ! I did it again on paper one day after your explanations and I manage to crack it, not exactly like you but I found the Xwings, the pointing pairs and after worked with finding Xchain ☺ Thank you because that is this level I like to exercise to improve ☺ Best regards. Françoise
Outstanding, Francoise! So great to hear from you. Glad to know that you continue to improve your solving skills.
I did it last night, and had to sleep right after. What I remember: three or four X-wings, a Y-wing, and a "nice continuous loop"? I still had to bifurcate.
0:40 That 8? Placed early as my first digit. My second digit was far later -- a 3 in the corner if I recall correctly. (BTW, a TH-cam video has a song about 3 in the corner.)
4:40 Your question: shortly before I reached that point, while I was still cornermarking 8s, I found and applied an X-wing in 8s -- rows 1 and 9. At your point in the grid, I found the X-wing in 4s -- columns 1 and 9. Then I centermarked a few blocks, and tried finding restricted cells, to minimal success. I returned to centermarking blocks. The next feature was a 567 triple in column 3.
5:10 I found that 249 triple backwards: instead, I found the 1567 quad in row 3. (It chopped five-digit cells down to two or three digits.) One interesting feature that wasn't useful in itself: the four corners were all bivalued cells, X9 -- 9 and some other digit.
7:00 I found the X-wing in 2s before finding the 1567 quad. It was my third X-wing. And now, I noticed something I missed in my solve: two of the cells -- R5C1 and R5C9 -- were common to both the 2 and 4 X-wings. That gave a 24 pair that I missed, due to clutter.
11:10 You never saw that before? It appeared a couple times on CtC, where I first learned it. I once saw three swordfish that shared the same cells in a column. That gave a triple.
11:50 Because I didn't think of the 24 pair, I didn't get the 3 until a 259 Y-wing.
12:40 The 6s were my final X-wing, the 8s were my first X-wing, and like 24, I didn't get the 68 pair.
16:50 Again, I found the 34 pair backwards: I saw the 567 triple first.
19:10 The Y-wing that I found was completely different: 259 in columns 1 and 2. It gave me the 3 in the corner and removed a bunch of 9s.
Video's END: I found this loop, which I believe is a form of "nice continuous loop": rows 2 and 9, columns 1 and 9. Counterclockwise from R9C9: 59, 19, 12, 25. Because of everything I missed, I still bifurcated.
About clutter: centermarking the grid lets me find positions that I usually would otherwise miss. The disadvantage: I miss things.
Nice job finding the loop, John. There were a few different ways to approach this after the X-Wings.
Thank you very much Timberlake, that is such a great puzzle ! I did it again on paper one day after your explanations and I manage to crack it. Thank you so much because that is the level I like to exercise . Best regards. Françoise
Nice job, Francoise!
I find this type of puzzle layout difficult. I didn't see any clue as when to pull off basic Snydering and start coloring single candidates, so I just kept filling in possibly restricted cells until it appeared no longer useful. Then I started coloring single candidates and found x-wings. But there is no good way to notate cells that have been eliminated using x-wings, so I fill in all the other cells in the block with the candidate (using corner marking), which eliminates the usefulness of Snyder. So then the board was very cluttered and I wasn't able to remember which x-wings overlapped. Total puzzle solve time, 1:42, not counting time watching the video or filling out the comment.
Great to hear from you Brad!
At the point in the solve that you asked about I noticed BVC's in the corners, then looked for (and thought I found) a swordfish on ones that eliminated 1 from r3c5. ThIs gave me a great boost on completing r1, r9, c1 & c9... until a conflict on 4's popped up at the extremities of the middle row. Then I came back hoping to learn where I had taken a wrong turn... and learned a new XY trick, and learned that I need to study swordfishes (yet again). Thanks for another nice video.
Thank you so much for watching and for sharing your feedback. It is cool that out of all of that you were able to learn a new trick. 😀
Brilliant puzzle and looked very hard to solve with so much to spot! Thanks Timberlake
You are welcome, Jon. I was blown away by the cleverness of this one. Truly deserved to be highly rated on LMD.
Ive been doing sudoku in Freeform(that one drawing app) for a bit now, but now I’ve gotten good at all variants of column restriction eliminations-xwing, swordfish, jellyfish kraken etc. I manually highlight the candidate num and start from the highest going down, and eliminate possible rows for usage if they don’t align with any others up to whatever number of columns it’s restricted to. I’ve actually gotten very quick at doing this, but the slow thing for me is filling in all candidates in the cells and doing the highlighting. Is there some app that has features like this? Or perhaps even an app that will make all solves restricted to certain strategies so you can focus on weaknesses?
I am so happy to hear about your progress. I like to use Hodoku desktop app to pre-fill candidates and use their practice and learning modes to create puzzles with specific strategies. Here is a link to my tutorial where I show you how to do both easily: th-cam.com/video/QCVOSevcYoI/w-d-xo.htmlsi=tlOX8K5NsB6ODJkC
@@SmartHobbies awesome, thanks!
What a beautiful puzzle and a real joy. I loved all the different techniques needed. I saw it differently from how you did- I saw the naked quad first, and same for the triple into the 34. For a reason unknown, I didn’t see the XY wing in the usual way. Early on I recognised the corner cells were BV cells, and that at least one must contain a 9. It was clearly an unintended solve path and sent me on some long, complicated adventures 😂 ultimately I saw it as rings on R1C1/ R1C9/ R9C1/ R9C9 and R1C2/ R1C8/ R9C2/ R9C8, with some eliminations possible, after all the lovely x-wings first of course. I wish I’d have unfolded the story of it in the intended way though, just fabulous sudoku creation. One to save to my favourites.
Outstanding, Paula. Glad you liked it!
A war of attrition, but a fun one. Anything but a notation-free quickie. The overlapping X-Wings were most satisfying. My version of HoDoKu rates the puzzle as Unfair rather than Hard, but with the same score. Intriguingly, the broken symmetry might be made symmetrical with only the slightest tweak, yielding a puzzle of very similar difficulty and a near-identical solution path:
001 204 500
004 090 060
800 000 003
100 009 005
009 000 600
Cool. I loved the basic idea of this puzzle. I need to check your variation out, Julian.
That was a pretty good puzzle
After seeing all the restrictions you marked with snyder notions, I saw the X Wings of 2s and 4s in columns 1 and 9 (which cause 24s to be a pair in r5c1+9. and then the X Wings of 6 and 8 in rows 1 and 9 (which cause 68 to be a pair in r1+9c5.. Then the clear certainty is that the 3 must be in r1c1. Then I completed the puzzle and as everything seemed to work well, I ended up with a mistake of 2s and 5s only in blocks 5 and 6. I know my mistake originated in block 1. I need to review what I did wrong there. I suspect now that a 5 must be in r9c1 I placed it in r2c1, and hebce a 9 in r9c1
Oh wow. I hope you figure it out Georges. Thank you for sharing.
This is a tough one! Thank you for showing the techniques. You illustrated how to locate the X wings by highlighting the cells where 2 (in this particular example) could be placed. Is this the best way to find an X wings by highlighting all the possible cells? Is it faster than putting in notations in all the cells? I need to find an app that would allow me to do such highlighting if that is the most efficient way. Thank you!
Great question, Kenneth. I find it easier to see when highlighting all the cells. Hodoku on desktop does it quickly by clicking on the digit filters at the top, and you can use SudokuPad to do it manually via desktop or mobile. I do not know of any phone app that does candidate highlighting. If you find one, please share with the rest of us.
With paper and pencil, I focus on conjugate pair restrictions for specific candidates and then compare rows or columns to find X-Wings, skyscrapers, 2-string kites, empty rectangles, finned X-Wings, etc. Hope that helps.
@@SmartHobbies Thank you so much for your reply! I downloaded SudokuPad. Is it true that this app does not erase the same number in related cells when you input a correct number? Either it’s my old age or there is a bug in the program because when I put in a correct number, it gave me the message of it being wrong. I checked this number over several times and I did not make a mistake!
@@kennethmiu691 you can turn on conflict checker in the settings and you should see numbers turn red when you put 2 of the same digit in a house. You can also select in settings whether to remove or keep pencil markings after you solve a cell. I am not sure why it is telling you a digit is wrong when it should not be.
@@SmartHobbies Great! Thank you again for the pointers. I will definitely re-set the controls. The coloring and the hint in the one I just solved were very useful, allowing me to learn more about the techniques. Thank you!
I saw the x-wings for 4 and got stuck. The video showing me the x-wings for 2 and the hidden 24 pair was what I needed to solve it.
Way to go, Mike! I am glad you found the video helpful.☺😀
Spotted everything except for XY wing.
Nice job! What did you use at the end to completely crack it?
@@SmartHobbiesI remember getting x wings on 2,4,6,8.
Got 68 pair in col 5 ( due to overlapping of 6/8 x wings)
I think in row 5 , instead of writing 24 pair, i wrote 234 on one end at R5C1 and 24 on the other end at R5C9.
Got row3 with 1567 quad and also 34 pair in col3, pointing 7's in top row of box 3.
I used a diff loop involving cols 1 and 9, rows 2 and 9 ( 12-->19-->59-->25) but that helped me to get rid of just one 5 at R8C1.
Bla bla...
Then I sneaked into ur video to complete the puzzle.
Great puzzle indeed.
If you are trying to teach difficult solving strategies (much appreciated) why do you spend so much time going over the very basics?
Great question. I have several people come to my channel through my beginner and intermediate tutorials. I run through the basics to try and bridge the gap between basic and more advanced strategies. Are there particular strategies or difficulty level you would like to see, Michael?
6:16 How is square 35 & 36 a pointing pair of 1's when square 26 & 36 can also be a pair of 1's? And 37 can also be a 1. So far I am not seeing how any of this is helpful. But I am looking at a grid where all of the helper bits are being shown. I'll keep watching.
I misspoke about the 1s being a pointing pair there. Once the hidden triple is revealed, they are just Snyder 1’s with 2 spots remaining in each block. I apologize for the confusion. Thank you for pointing that out.