Many thanks to Simon for setting this sudoku for me! I'm sure it would have taken me ages to figure out where to place all the lines, so this has been most helpful indeed. It was nice to take a day off.
I've always wanted to set a sudoku like this one. But it seems you beat me to it with a very elegant puzzle, more elegant than mine would ever be. Thanks!
I bet you have a great grasp of transformations (including rotations, reflections and y = 10 - x). And an out-of-scale level of creativity. And I would be surprised if you had not used *placeholder digits* to build and test this mind-blowing puzzle, as I did to solve it. I explained my technique in a separate comment.
I love the irony of a puzzle that is built on a fictional pretense of "slacking off" when in reality it is an intricately thoughtfully set puzzle that cannot have been easy to construct
@@karthick_michigooner7431Not quite, as even with that rule you can still mirror vertically in the 5th row and get another solution. Only the signature removes that symmetry
@@karthick_michigooner7431 It probably does theoretically/structurally but in terms of solve path can't imagine the depth of bifurcation needed to get enough info to use the eastbound arrow to differentiate the positions of the other lines using that before already having it from the sig...
Before the year is out we'll have an empty grid, regular sudoku rules, one constraint and a 3 in one of the corners. And Simon's solve will entertain us for a whole weekend.
You joke, but it turns out there's a total-kropki puzzle with a *single* dot (and no other clues or constraints) that has a unique solution. I wouldn't recommend trying to solve it though.
@@thejuggler42 extra funny thing: it doesn't even matter what color the dot is in that puzzle, both choices end up having the same unique solution apparently which is Wild
I'm 1 second into the video (post opening credits) and have only got as far as reading the rules, and I'm already grinning like an idiot. This is astonishing!
The key moment for me was that any configuration that fulfills anti-bishop + sudoku also fulfills anti-king, so there's no need to look for anti-bishop at all.
Simon puts a 4 in a box that already has a 4. "It looks at first blush like it's going to clash". (Silence) "I need to just think about this. Hang on."
Simon went through most of my break in, but it was a bit hard to follow in the video. so here's my explanation of the break in which i thought was really beautiful. We need a few observations 1. if the thermo intersects the vertical whisper, then the have a knights move clash. this is done by looking at the digit above or below the digit in the intersection on both lines. at least 1 pair of them will be a knights move away. simon showed this during the video. 2. the thermo has to intersect the whisper. If it doesn't, then the thermo has to intersect with the 5 outside of the whisper. but in this case the 4 or 6 in the first cell of the whisper would clash with the 4 and 6 in the box. 3. if the 2 whispers cross then they have both a king and bishop clash. because there's only 1 possible whisper (ignoring reversing which doesn't change the point), then the cells next to the intersection in doth directions will be the same and cause a diagonal clash. 4. by 1 and 2 there is a knight clash. 5. by 3 and 4 there is no intersection between the 2 whispers. with 5. we know that the whispers go on the edges, and like simon pointed out, they can only go on the top and left or they would overlap the signature.
That's beautiful! I broke in by "deducing" that the german whispers couldn't clash because that would be aesthetically unpleasant lmao (i'm astonished that my silly mistake was not only correct but also let me skip such massive and wild breakins)
After reading the title, I was more thinking "What ludacris *Constructors, don't do this* suggestion, did Simon make recently?" However this one is even better. It is so clever and beautifully non-set. Kudos to you.
This must be the most delightful sudoku I've solved in the last several months, or maybe ever. No crazy complicated disjoint rules, just pure elegance and wit from start to end. And, I must say, the way the instructions are written is just tiny endearing piece of kindness. I've enjoyed this immensely, thank you to Michael and to CtC for featuring it!
Absolutely stunning ... I quickly got the restrictions on the German Whisper lines and came to the same conclusion with the 5 in the top corner, and pretty much giggled at every move since it's just so damn clever.
15:23 finish. I started off with the first conclusion: any time you break a king's move, you break a bishop's move. Then I crossed two full German Whispers lines, and realized that you will always break a king's move. After, I crossed a full German Whisper with a full Thermometer and saw that you always break a knight's move. Since the two crossings will eliminate all chess move constraints, only one of the two pairs of lines can cross. The only way for the thermo and whisper to not cross is for the thermo to use the 5 in the whisper column. This forces the whisper line to use column 5 and the thermo row 1 (row 9 would hit the signature). This would place a duplicate 4 or 6 in box 2. Therefore, the thermo and whisper cross, the whispers don't cross and must run along row and column 1, with a 5 in the corner (all other rotations would hit the signature). Most of the line logic was resolved quite early in the puzzle, with only the arrow remaining, and so it turned into a basic king's move sudoku until the end, when the arrow needed to be identified. An excellent puzzle, and the first one I've ever set! (Please don't ask me for a follow-up... it may take a few years.) 🤣🤣🤣
I am in awe of how many amazing puzzles are showcased on this channel! And watching Simon’s total delight as he unravels their mysteries for our entertainment every day!! Over 575,000 of us show up regularly to bask in the magic!
I finished in 122 minutes. This is one of the most beautiful sudokus I have ever done. I love the theming of this puzzle so much. It is brilliant the construction of this puzzle. I was lost for a while, before I started focusing on the horizontal german whisper and how it interacts with the vertical german whisper. Figuring out that they can't intersect was really fun to discover. I love how Michael's signature was used as a disambiguation for these german whispers. I was joyed when I saw that the 3 in the corner was on Michael's signature. From there, everything broke down, especially when I saw a 2 was a knight's move away from another 2 and that the 9 on my zipper saw a 9 on the horizontal german whisper. Absolutely brilliant. Great Puzzle!
The lengths Simon goes to to avoid simply positing a complete vertical German whispers in the grid at the same time as having posited a horizontal one is amazing since doing so would quickly convince someone that the overlap points could only be possible within one diagonal line on either side of the main diagonal from NW to SE... then subsequently finding a very short list of possible options.
@@RichSmith77 You are right. I think when I posted that it was soon after watching Simon reason about the 5 only working in the NW and not NE (and SW by symmetry and SE more directly all dues to the signature) so in my head I eliminating the NE and SW possibility.
Simon appears to be always reluctant to use placeholders, which allow you to solve ingoring the difference between *N* and *10-N,* and ignoring the orientation of your lines... However, in this case this technique was quite tricky to apply, because you needed to allow for a double transformation: a "complementation" (y = 10 - x) and a rotation/reflection. I guess Richard was able to use it. See my separate comment for details.
i had the privilege of testing this puzzle and the ruleset absolutely floored me when i saw it, the fact that it solved uniquely was sick. colossal props to the setter for somehow imagining this, and the signature was the cherry on top
Wow. Surprised myself with that one. 54:35. The longest part was working out where the German whisper lines went, then it all fell into place. Amazing that such an idea can actually work. Michael you are a genius.
Wow, that's someting. Took me 2 hours, but that was a great experience! First it started with: how could I even start this? Obviously there are a lot of possible places for those lines! Pretty soon it went to: Is there even one posibility to place those lines according to the rules? And then I totally forgot the '3 in the corner' rule, so I've wasted alot of time for nothing. But finally finishing it was awesome! The person who set those is a genius!
I have a bone to pick with Sven. When I clicked Tick it told me solved the puzzle correct BUT it didnt tell me if I set the puzzle correctly! Now I am lost in a reality with an Puzzle that may or may not be set correctly. I am become despair. Jokes aside, love your software Sven. Keep up the grand work.
Oh no. I was just experimenting to see how this ruleset worked. I made an initial hypothesis as to how it could possibly work. And then I did the next line. And the next one. And realized what the ruleset had to be in this most absurd of bifurcations. Found the last line. And kept going, knowing it would fall over at some point. And then 24:51 later...You solved the puzzle! The solution is correct! Whoopsie
I've never seen myself as a setter and having solved this I still don't see myself as a setter. This does not seem plausible at the start and yet it is so very clever stuff, well done.
I've seen Simon solve many puzzles on this channel but I think this is the first one I've seen him set, it's a very impressive debut. (On a separate note, I imagine it would be pretty easy to solve this puzzle if you had the rules/lines but no digits in the grid, but that would be really interesting to see, too.)
As a chess player, let me clear one thing: In sudoku, the anti-bishop rule includes anti-king since anti-rook is already standard in normal sudoku :) So from the start we only need to find out anti-knight or anti-king.
@@sirenier you're right about that, but it's exactly what I mean. If a bishop would only be able to go one square, I would have written that king and bishop sudoku rule were the same. To find out that the bishop rule is gone is a nice side effect for the solver of this puzzle, but there is no need to do it.
@@sirenier The point is that any puzzle that has an anti-bishop rule _automatically_ also obeys an anti-king rule. (Unless it's one of those weird ones where digits can repeat in rows/columns 😵💫) . But I think it's the case that you can't have a puzzle with a global anti-bishop rule, it isn't possible to fill all 81 cells without _any_ digit seeing itself on a diagonal. You can do it with the anti-bishop rule applying to all instances of _some_ digits, I think maybe up to about 6 can work, but not all 9.
I believe it's been proven that you can't have a 9-digit anti-bishop rule. I believe the anti-bishop rule only allows as many as six different digits to follow the rule. I could be wrong - it's been a long time. If that had been the case, though - a six-digit anti-bishop rule - this puzzle would have been absolutely brutal.
Just again remarkable what setters can come up with for this community. Truly remarkable how nearly 600,000 can come together to see absolute magic on a daily basis and someone solve that magic with such happiness and love!!
This puzzle had me grinning throughout the entirety of the solve. I did it in 25 minutes, and 15 of those was staring blankly as I tried to work out German whispers orientations.
they really say all ingenious is simple huh. this might be the most interesting sudoku i've ever solved, it's giving "i won the idgaf war wink-wink". this requires such a level of comfort with all the possible symmetries (of the digits and the line positions) that i can easily see how it seems hard without digging deeper... managed to crack it in 38 minutes, most of them spent proving all other green line combos don't work. the rest is so smooth and intuitive.
someone replied to me wondering why think about the green line combos (and then deleted their comment? i can't see it unfortunately). well because every sudoku is a problem that requires deductions that build on other deductions and the limitations that are given to you, and finding one solution overall doesn't mean you proved other solutions don't exist. it's a lot like math, it requires that rigor. i also pretty much instantly thought german whispers go into r1 and c1 simply judging by the ruleset and its simplicity, so i decided to eliminate other possibilities first. and you do that eventually with anti-chess rules and it's just beautiful. going straight to the deduction based on experience and intuition would've bugged me.
It's the first ctc sodoku that captivated me to try and solve it myself. Really liked the German whispers intersection thinking, but got stuck not noticing the knights move due to the thermo
Absolutely brilliant puzzle. Felt absolutely impossible, then spot the break-in, then the whole thing just sort of unfolds. My 38:47 feels like both a really fast and really slow time somehow. Take a bow Michael :) I think this about sums it up: "The process was wonderfully beautiful. It was extraordinarily elaborate but also simple and elegant. It was like a piece of self-opening origami, or a rosebud blooming into a rose in just a few seconds." - Mostly Harmless by Douglas Adams
1:21:10 - Wow! That is an absolute classic puzzle! Well done Michael. I considered the implications overnight and realised I had the break in first thing this morning. Gorgeous logic throughout.
68 minutes. It was so much fun after I figured out what was going on. The intersecting whisper lines made for a quick break-in, but the chess logic tripped me up. At first, I thought I had to accommodate all of the chess constraints. When I realized that the intersecting whisper and thermo lines ruled out the anti-knights move constraint, and that I had to preserve at least one of the others (either anti-bishop or anti-king), then it filled in rather quickly.
Took me more than 2 hours, but finally made it. Enjoyed every single minute of it, despite sometimes being stuck at not so difficult places. And actually - the puzzle was not that difficult, the break-in was pretty straight-forward, it was mostly sudoku part that slowed me down. Now it is time for popcorn and watch how Simon goes through it :)
I wouldn't recommend misreading the rules as requiring no 3 in the corner. It makes the first task of placing the german whispers and thermo a lot harder (but not impossible), but then ultimately leads to multiple possible solutions.
I absolutely love this puzzle. The realization that the whisper line and thermo intersecting breaks the knight's move constraint, and that that's generalizable... chef's kiss, what an incredibly set puzzle by Simon (and Michael 😉)
When it suddenly hit me that the defined nature of the order of digits on a max-length Whisper means that, if two of them overlap anywhere but on the 5, it will cause a clash by knight's and king's move, and that the spacing of consecutive digits on a max-length Whisper will always cause a clash with a max-length Thermometer that overlaps with it by knight's move, meaning the Whispers *have* to overlap at the corner NO MATTER which chess constraint is used, I literally stopped and said "Oh my god" out loud. That's not something that happens too often with a sudoku puzzle!
This was fascinating. Mesmerizing. I agree, Simon, this seemed harder than three star puzzles have seemed to me in the past (all from a watching perspective, I assure you). Thank you for making the effort to rigorously prove the various interactions, because it helped me understand the general outlines as well as the specifics. I will be a better solver because of watching this!
Brilliant puzzle and like many others my time was better than I expected - 47:37. As someone else commented getting the two whisper lines positioned gets you a long way.
This puzzle is amazing, very happy to see it featured. What a brilliant concept and hilarious set of rules. I tested an earlier version that didn't have a zipper or arrow, but had a region sum line. That was brilliant, but this final version takes it to a whole new level of genius.
A clever way to think of the whispers crossing at the start is to use a little bit of nonogram logic - you're using 8 out of 9 cells in a row in a fixed order, so there's only 1 cell of wiggle room. This means the first two digits 49 are *always* going to share a box. The same goes for the middle pair 82, and the same again for the final pair 16. This means the whisper lines could never overlap on any of those digits 49_82_16, because those digits would always need to have their neighbour in the same box both vertically and horizontally. (For example if the lines intersected at a 6, then there would be two 4's in the box with the 6 intersection, one vertically and one horizontally from the 6.) This leaves only 7 and 3 as possible crossings mid-line, as 7 can share a box with either 82 or 16, and 3 can share a box with either 49 or 82. Of course, once you get the generalized logic Simon came up with, which really is quite incredible, all that is a bit unnecessary, but I thought it was an interesting sort of inherent restriction on these 8 cell whispers crossing.
The chess constraint could never be a bishop one, because there could never be a way to rule out that it's a king's constraint one because bishop constraint + sudoku rules contain the kings constraint (but not the other way around).
The big manual Remington typewriter I learned to type on in 1958 didn't have a number pad. Now I have a top-of-the-line laptop computer, and it doesn't have a number pad either. Never slowed me down. Go, Simon!
I've almost always had numpads (born in 95) but I learned how to type on the regular keyboard and the upper numbers always did feel like the most natural ones so I just never bothered learning how to type fast on a numpad. Never slowed me down either. Honestly, I have no idea why they even bother putting it there.
@@thespanishinquisition4078 it CAN make calculations faster, particulary for spreadsheets. (I had a spreadsheet of telephone numbers and it was a pain doing it on a laptop with no number pad
20:50 This is a logical mistake. The vertical whisper lines could, in theory, fit into column 8 or 9 because its length is 8 (5 is not part of the whisper line) on top of the signature
There is no 9x9 sudoku with an anti-bishop (or anti-queen) constraint. You can get CLOSE to one, but there's no way to combine nine different 9-solutions of the N-queens-problem to cover the full grid.
Not a hugely important detail, but you can prove that anti-bishop is incorrect a bit sooner in the puzzle - as soon as you place the 3 in the corner, in fact - by looking at where 3 would go in box 1 if there was an anti-bishop constraint
The amount of work the indeterminate anti-chess requirement in this instruction set (I refuse to call it a rule set) did to move the solve forward was astounding.
By my calculations, there are just over 10 million combinations of these rules, so I think Michael might be the single most prolific setter in history :P
Man this was the best construction I've had the opportunity to test out so far, it was very interesting trying to find out the constraints and how to use them properly to understand the grid. And I'm glad it only took 32 minutes to do, but man was it so enjoyable, I found the German whisper constraint the easiest to find out, Then after that the Zipper line felt very natural, and so did the Thermo, the only thing that stumped me was the Arrow, however in the end when I had basically shoved in every possible value in the cells, there was only one place to place the arrow and the solution after that was very easy.
Though I'm sure it violates the spirit of this puzzle, you can rule anti-bishop out by uniqueness from the beginning, since any anti-bishop puzzle would also qualify as anti-king.
After taking over 2 1/2 hours to solve IcyFruit's zipper line puzzle, I was a little bit gun shy taking on another solve that had a long video but glad I did. Excellent puzzle and in the end it took me 35:06. Now to watch the video. Still don't think I've recovered enough to watch the zipper line puzzle yet!
At 20:53, is it presumptuous for Simon to exclude the non-whisper vertical 5s from Michael's signature cells? It might be apparent later, but he doesn't really justify it here.
I was also thinking about it. But it actually is impossible given the horizontal whispers couldn't be in row 9 If we try and put the vertical whispers in column 9, the horizontal whispers have to share a 4 or a 6 as a common digit. And that would only be possible in r1c9, making r1c8 and r2c9 the same digit
The ruleset reminds me of a sudoku supposedly made by a colorblind setter in which all the "colored" lines were grey. I checked that it was actually made by the same person.
Many thanks to Simon for setting this sudoku for me! I'm sure it would have taken me ages to figure out where to place all the lines, so this has been most helpful indeed. It was nice to take a day off.
This puzzle has been criminally underrated on LMD, so glad it got a feature
Thank you for letting us do some setting.
Such a genius idea!
I've always wanted to set a sudoku like this one. But it seems you beat me to it with a very elegant puzzle, more elegant than mine would ever be. Thanks!
I bet you have a great grasp of transformations (including rotations, reflections and y = 10 - x). And an out-of-scale level of creativity.
And I would be surprised if you had not used *placeholder digits* to build and test this mind-blowing puzzle, as I did to solve it.
I explained my technique in a separate comment.
I love the irony of a puzzle that is built on a fictional pretense of "slacking off" when in reality it is an intricately thoughtfully set puzzle that cannot have been easy to construct
The theming is immaculate
The signature is such a clever and thematic way to avoid a symmetric ambiguity...
I yhink arrow to the east also does take care of the ambiguity
It really is!
@@karthick_michigooner7431Not quite, as even with that rule you can still mirror vertically in the 5th row and get another solution. Only the signature removes that symmetry
@@karthick_michigooner7431 It probably does theoretically/structurally but in terms of solve path can't imagine the depth of bifurcation needed to get enough info to use the eastbound arrow to differentiate the positions of the other lines using that before already having it from the sig...
@@karthick_michigooner7431 The arrow alone does not solve it, because you could flip the solution vertically. Only the signature prevents that.
“That’s very bad, because that works.” - Sentences you don’t expect to hear, but make perfect sense in context.
A hypothesis cannot be right unless it can be proven wrong
The number of times Simon disappointedly says "Oh, that works..." in his videos.
I love that Michael is actually the "me" in the corner for this puzzle. :)
Hah, I didn't even realize I'd fixed the song lyrics back to the original REM ones.
😁
And very much in the spotlight.
@@Anne_Mahoney 👆🏻🔦
If you look even closer at it, the 3 replaces the e in Michael, which is the coolest detail ever in a sudoku
This is officially the most genius sudoku in the history of sudoku in my book. We've peaked. Time to wrap up. Everybody go home. *starts packing bags*
The great thing about variant sudoku in the age of CtC is that every time we peak some brilliant mind finds a higher mountain for everyone to climb.
Sudoku is peaking for more than 2 years now and its never going to go down
Before the year is out we'll have an empty grid, regular sudoku rules, one constraint and a 3 in one of the corners. And Simon's solve will entertain us for a whole weekend.
Sounds ridiculous. I'll get to work.
@@Jaze327😁
You joke, but it turns out there's a total-kropki puzzle with a *single* dot (and no other clues or constraints) that has a unique solution. I wouldn't recommend trying to solve it though.
@@thejuggler42 is it on yt?
@@thejuggler42 extra funny thing: it doesn't even matter what color the dot is in that puzzle, both choices end up having the same unique solution apparently which is Wild
I'm 1 second into the video (post opening credits) and have only got as far as reading the rules, and I'm already grinning like an idiot. This is astonishing!
Same here, currently 2 am and I'm 5 mins into the video and I doubt I'll be able to resist watching the whole thing 😅
It's funny when he says he can't do something "because of the Michael". Oh, we can't put a 5 there because of the Michael.
The key moment for me was that any configuration that fulfills anti-bishop + sudoku also fulfills anti-king, so there's no need to look for anti-bishop at all.
Simon puts a 4 in a box that already has a 4.
"It looks at first blush like it's going to clash".
(Silence)
"I need to just think about this. Hang on."
He does this so often. His wizardry distracts him from the easy answers. LOL
Michael Lefkowitz making Simon do sudoku in his sudoku puzzle is outrageous to be fair
Simon went through most of my break in, but it was a bit hard to follow in the video. so here's my explanation of the break in which i thought was really beautiful. We need a few observations
1. if the thermo intersects the vertical whisper, then the have a knights move clash. this is done by looking at the digit above or below the digit in the intersection on both lines. at least 1 pair of them will be a knights move away. simon showed this during the video.
2. the thermo has to intersect the whisper. If it doesn't, then the thermo has to intersect with the 5 outside of the whisper. but in this case the 4 or 6 in the first cell of the whisper would clash with the 4 and 6 in the box.
3. if the 2 whispers cross then they have both a king and bishop clash. because there's only 1 possible whisper (ignoring reversing which doesn't change the point), then the cells next to the intersection in doth directions will be the same and cause a diagonal clash.
4. by 1 and 2 there is a knight clash.
5. by 3 and 4 there is no intersection between the 2 whispers.
with 5. we know that the whispers go on the edges, and like simon pointed out, they can only go on the top and left or they would overlap the signature.
This is an excellent and concise proof.
Thanks for the clear proof, it helped me clear the mess of my assumptions and complete the puzzle.
That's beautiful! I broke in by "deducing" that the german whispers couldn't clash because that would be aesthetically unpleasant lmao (i'm astonished that my silly mistake was not only correct but also let me skip such massive and wild breakins)
This was very approachable quick puzzle... after setting it for 80 minutes
After reading the title, I was more thinking "What ludacris *Constructors, don't do this* suggestion, did Simon make recently?"
However this one is even better.
It is so clever and beautifully non-set.
Kudos to you.
This must be the most delightful sudoku I've solved in the last several months, or maybe ever. No crazy complicated disjoint rules, just pure elegance and wit from start to end. And, I must say, the way the instructions are written is just tiny endearing piece of kindness. I've enjoyed this immensely, thank you to Michael and to CtC for featuring it!
The reason Cracking The Cryptic makes you very employable is because every day you turn up to find a new set of rules have to be followed.
Absolutely stunning ... I quickly got the restrictions on the German Whisper lines and came to the same conclusion with the 5 in the top corner, and pretty much giggled at every move since it's just so damn clever.
15:23 finish. I started off with the first conclusion: any time you break a king's move, you break a bishop's move. Then I crossed two full German Whispers lines, and realized that you will always break a king's move. After, I crossed a full German Whisper with a full Thermometer and saw that you always break a knight's move. Since the two crossings will eliminate all chess move constraints, only one of the two pairs of lines can cross. The only way for the thermo and whisper to not cross is for the thermo to use the 5 in the whisper column. This forces the whisper line to use column 5 and the thermo row 1 (row 9 would hit the signature). This would place a duplicate 4 or 6 in box 2. Therefore, the thermo and whisper cross, the whispers don't cross and must run along row and column 1, with a 5 in the corner (all other rotations would hit the signature).
Most of the line logic was resolved quite early in the puzzle, with only the arrow remaining, and so it turned into a basic king's move sudoku until the end, when the arrow needed to be identified. An excellent puzzle, and the first one I've ever set! (Please don't ask me for a follow-up... it may take a few years.) 🤣🤣🤣
Not often, but once in a while a sudoku rule set can actually make me laugh. This is one of those times. I look forward to trying it. Kind comment.
00:43:08 for me. That was a fantastic puzzle! From the reading of the rules to the entering of the final digit.
“I can’t think about the anti-chess constraint, I think that’s going to be where madness lies” HAHAHAHA this got me laughing for a long time 😂
A great line that had me chuckling too. I love Simon's humor.
21:08 for me. What a wonderful puzzle!! That ruleset is one of the greatest ideas I've seen in a while, kudos to the setter for coming up with it.
This ruleset is both hilarious and amazingly cleaver. The signature is a great way to disambiguate the symmetry.
I am in awe of how many amazing puzzles are showcased on this channel! And watching Simon’s total delight as he unravels their mysteries for our entertainment every day!! Over 575,000 of us show up regularly to bask in the magic!
Perfectly written! This channel seizes to amaze me on a daily basis. We are blessed to be part of something immaculate every day!!
@@davidrattner9 absolutely, my friend!
I saw the rules and thought, I'm just going to watch Simon do it. I was not disappointed.
I finished in 122 minutes. This is one of the most beautiful sudokus I have ever done. I love the theming of this puzzle so much. It is brilliant the construction of this puzzle. I was lost for a while, before I started focusing on the horizontal german whisper and how it interacts with the vertical german whisper. Figuring out that they can't intersect was really fun to discover. I love how Michael's signature was used as a disambiguation for these german whispers. I was joyed when I saw that the 3 in the corner was on Michael's signature. From there, everything broke down, especially when I saw a 2 was a knight's move away from another 2 and that the 9 on my zipper saw a 9 on the horizontal german whisper. Absolutely brilliant. Great Puzzle!
The lengths Simon goes to to avoid simply positing a complete vertical German whispers in the grid at the same time as having posited a horizontal one is amazing since doing so would quickly convince someone that the overlap points could only be possible within one diagonal line on either side of the main diagonal from NW to SE... then subsequently finding a very short list of possible options.
Why not also from SW to NE, if one of the GW lines is flipped?
@@RichSmith77 You are right. I think when I posted that it was soon after watching Simon reason about the 5 only working in the NW and not NE (and SW by symmetry and SE more directly all dues to the signature) so in my head I eliminating the NE and SW possibility.
Simon appears to be always reluctant to use placeholders, which allow you to solve ingoring the difference between *N* and *10-N,* and ignoring the orientation of your lines... However, in this case this technique was quite tricky to apply, because you needed to allow for a double transformation: a "complementation" (y = 10 - x) and a rotation/reflection. I guess Richard was able to use it.
See my separate comment for details.
i had the privilege of testing this puzzle and the ruleset absolutely floored me when i saw it, the fact that it solved uniquely was sick. colossal props to the setter for somehow imagining this, and the signature was the cherry on top
Wow. Surprised myself with that one. 54:35. The longest part was working out where the German whisper lines went, then it all fell into place. Amazing that such an idea can actually work. Michael you are a genius.
Wow, that's someting. Took me 2 hours, but that was a great experience!
First it started with: how could I even start this? Obviously there are a lot of possible places for those lines!
Pretty soon it went to: Is there even one posibility to place those lines according to the rules?
And then I totally forgot the '3 in the corner' rule, so I've wasted alot of time for nothing.
But finally finishing it was awesome!
The person who set those is a genius!
I have a bone to pick with Sven. When I clicked Tick it told me solved the puzzle correct BUT it didnt tell me if I set the puzzle correctly! Now I am lost in a reality with an Puzzle that may or may not be set correctly. I am become despair.
Jokes aside, love your software Sven. Keep up the grand work.
Oh no. I was just experimenting to see how this ruleset worked. I made an initial hypothesis as to how it could possibly work. And then I did the next line. And the next one. And realized what the ruleset had to be in this most absurd of bifurcations. Found the last line. And kept going, knowing it would fall over at some point. And then 24:51 later...You solved the puzzle! The solution is correct! Whoopsie
I've never seen myself as a setter and having solved this I still don't see myself as a setter. This does not seem plausible at the start and yet it is so very clever stuff, well done.
I've seen Simon solve many puzzles on this channel but I think this is the first one I've seen him set, it's a very impressive debut. (On a separate note, I imagine it would be pretty easy to solve this puzzle if you had the rules/lines but no digits in the grid, but that would be really interesting to see, too.)
As a chess player, let me clear one thing: In sudoku, the anti-bishop rule includes anti-king since anti-rook is already standard in normal sudoku :)
So from the start we only need to find out anti-knight or anti-king.
i may be wrong but cant a king only move one square but a bishop can move multiple? so anti Bishop would mean no repeats on any diagonals
@@sirenier you're right about that, but it's exactly what I mean. If a bishop would only be able to go one square, I would have written that king and bishop sudoku rule were the same. To find out that the bishop rule is gone is a nice side effect for the solver of this puzzle, but there is no need to do it.
@@sirenier The point is that any puzzle that has an anti-bishop rule _automatically_ also obeys an anti-king rule. (Unless it's one of those weird ones where digits can repeat in rows/columns 😵💫) .
But I think it's the case that you can't have a puzzle with a global anti-bishop rule, it isn't possible to fill all 81 cells without _any_ digit seeing itself on a diagonal. You can do it with the anti-bishop rule applying to all instances of _some_ digits, I think maybe up to about 6 can work, but not all 9.
Well spotted ;)
I believe it's been proven that you can't have a 9-digit anti-bishop rule. I believe the anti-bishop rule only allows as many as six different digits to follow the rule.
I could be wrong - it's been a long time.
If that had been the case, though - a six-digit anti-bishop rule - this puzzle would have been absolutely brutal.
What a brilliant, charming idea for a puzzle.
Continually blown away by the creativity people put into setting puzzles.
Just again remarkable what setters can come up with for this community. Truly remarkable how nearly 600,000 can come together to see absolute magic on a daily basis and someone solve that magic with such happiness and love!!
This puzzle had me grinning throughout the entirety of the solve. I did it in 25 minutes, and 15 of those was staring blankly as I tried to work out German whispers orientations.
they really say all ingenious is simple huh. this might be the most interesting sudoku i've ever solved, it's giving "i won the idgaf war wink-wink". this requires such a level of comfort with all the possible symmetries (of the digits and the line positions) that i can easily see how it seems hard without digging deeper...
managed to crack it in 38 minutes, most of them spent proving all other green line combos don't work. the rest is so smooth and intuitive.
someone replied to me wondering why think about the green line combos (and then deleted their comment? i can't see it unfortunately). well because every sudoku is a problem that requires deductions that build on other deductions and the limitations that are given to you, and finding one solution overall doesn't mean you proved other solutions don't exist. it's a lot like math, it requires that rigor.
i also pretty much instantly thought german whispers go into r1 and c1 simply judging by the ruleset and its simplicity, so i decided to eliminate other possibilities first. and you do that eventually with anti-chess rules and it's just beautiful. going straight to the deduction based on experience and intuition would've bugged me.
39:20 for me, extremely interesting rule set! The breakthrough is first realising the 5 in top left corner
That ruleset is absolutely glorious and had me falling off my chair in laughter.
It's the first ctc sodoku that captivated me to try and solve it myself.
Really liked the German whispers intersection thinking, but got stuck not noticing the knights move due to the thermo
I love this puzzle. I can’t even begin to do it, but I love it. It’s popcorn time for me!
Wait a minute, we made the same puzzle - what are the odds?!
Absolutely brilliant puzzle. Felt absolutely impossible, then spot the break-in, then the whole thing just sort of unfolds. My 38:47 feels like both a really fast and really slow time somehow. Take a bow Michael :)
I think this about sums it up:
"The process was wonderfully beautiful. It was extraordinarily elaborate but also simple and elegant. It was like a piece of self-opening origami, or a rosebud blooming into a rose in just a few seconds." - Mostly Harmless by Douglas Adams
26m07s. This was adorable! I'm glad I caught the double whisper logic so early, I could imagine that being a huge sticking point otherwise
I always say this, but this may just be the most elegant (and funny) sudoku on the channel so far.
1:21:10 - Wow! That is an absolute classic puzzle! Well done Michael. I considered the implications overnight and realised I had the break in first thing this morning. Gorgeous logic throughout.
Unbelievable puzzle. Was insanely fun to solve.
I've only read the rules and I love it already. This must be one of the most inticately crafted sudokus that have ever been set
This puzzle was a joy to explore! Well done!
Congratulation Simon on your sudoku setting depute. What a beautiful puzzle you have created.
68 minutes. It was so much fun after I figured out what was going on. The intersecting whisper lines made for a quick break-in, but the chess logic tripped me up. At first, I thought I had to accommodate all of the chess constraints. When I realized that the intersecting whisper and thermo lines ruled out the anti-knights move constraint, and that I had to preserve at least one of the others (either anti-bishop or anti-king), then it filled in rather quickly.
Took me more than 2 hours, but finally made it. Enjoyed every single minute of it, despite sometimes being stuck at not so difficult places. And actually - the puzzle was not that difficult, the break-in was pretty straight-forward, it was mostly sudoku part that slowed me down.
Now it is time for popcorn and watch how Simon goes through it :)
I wouldn't recommend misreading the rules as requiring no 3 in the corner. It makes the first task of placing the german whispers and thermo a lot harder (but not impossible), but then ultimately leads to multiple possible solutions.
Probably my favorite puzzle from the channel. The signature is *chef's kiss*
When I read the rules I thought, 'well, I'll never solve that' but it ended up being pretty easy. I solved it in less than half an hour.
I absolutely love this puzzle. The realization that the whisper line and thermo intersecting breaks the knight's move constraint, and that that's generalizable... chef's kiss, what an incredibly set puzzle by Simon (and Michael 😉)
The absolute audacity of this man
Wow! A piece of Sudoku gold. I stayed up incredibly late setting this one but I really wanted to get it done in one sitting.
Oh What a fun bunch of rules! Very creative with the copy, too!
It's interesting how different people's minds work. I got the initial placement of the German Whispers far faster than Simon but then got no further.
When it suddenly hit me that the defined nature of the order of digits on a max-length Whisper means that, if two of them overlap anywhere but on the 5, it will cause a clash by knight's and king's move, and that the spacing of consecutive digits on a max-length Whisper will always cause a clash with a max-length Thermometer that overlaps with it by knight's move, meaning the Whispers *have* to overlap at the corner NO MATTER which chess constraint is used, I literally stopped and said "Oh my god" out loud. That's not something that happens too often with a sudoku puzzle!
This was fascinating. Mesmerizing. I agree, Simon, this seemed harder than three star puzzles have seemed to me in the past (all from a watching perspective, I assure you). Thank you for making the effort to rigorously prove the various interactions, because it helped me understand the general outlines as well as the specifics. I will be a better solver because of watching this!
Brilliant puzzle and like many others my time was better than I expected - 47:37. As someone else commented getting the two whisper lines positioned gets you a long way.
64 minutes for me to set this puzzle. Thank you Michael, you made me one of the most brilliant setter in the world!
This puzzle is amazing, very happy to see it featured. What a brilliant concept and hilarious set of rules. I tested an earlier version that didn't have a zipper or arrow, but had a region sum line. That was brilliant, but this final version takes it to a whole new level of genius.
Thanks! Your playtesting of earlier versions of this puzzle was invaluable, it's a better puzzle because of it.
A clever way to think of the whispers crossing at the start is to use a little bit of nonogram logic - you're using 8 out of 9 cells in a row in a fixed order, so there's only 1 cell of wiggle room. This means the first two digits 49 are *always* going to share a box. The same goes for the middle pair 82, and the same again for the final pair 16. This means the whisper lines could never overlap on any of those digits 49_82_16, because those digits would always need to have their neighbour in the same box both vertically and horizontally. (For example if the lines intersected at a 6, then there would be two 4's in the box with the 6 intersection, one vertically and one horizontally from the 6.) This leaves only 7 and 3 as possible crossings mid-line, as 7 can share a box with either 82 or 16, and 3 can share a box with either 49 or 82.
Of course, once you get the generalized logic Simon came up with, which really is quite incredible, all that is a bit unnecessary, but I thought it was an interesting sort of inherent restriction on these 8 cell whispers crossing.
The chess constraint could never be a bishop one, because there could never be a way to rule out that it's a king's constraint one because bishop constraint + sudoku rules contain the kings constraint (but not the other way around).
The big manual Remington typewriter I learned to type on in 1958 didn't have a number pad. Now I have a top-of-the-line laptop computer, and it doesn't have a number pad either. Never slowed me down. Go, Simon!
I've almost always had numpads (born in 95) but I learned how to type on the regular keyboard and the upper numbers always did feel like the most natural ones so I just never bothered learning how to type fast on a numpad. Never slowed me down either. Honestly, I have no idea why they even bother putting it there.
@@thespanishinquisition4078 it CAN make calculations faster, particulary for spreadsheets. (I had a spreadsheet of telephone numbers and it was a pain doing it on a laptop with no number pad
20:50 This is a logical mistake. The vertical whisper lines could, in theory, fit into column 8 or 9 because its length is 8 (5 is not part of the whisper line) on top of the signature
I watched Simon as the rule set seemed very intimidating to me. Once you get the whispers lines it doesn't seem so bad.
Loved this puzzle! So clever
done in 71:29 I have to agree with all the comments you showed at the start, wonderful puzzle.
There is no 9x9 sudoku with an anti-bishop (or anti-queen) constraint. You can get CLOSE to one, but there's no way to combine nine different 9-solutions of the N-queens-problem to cover the full grid.
I bet Michael started singing when he realized what the 3 in the corner did for the puzzle
It is a very nice 3, isn't it?
i always enjoy watching simon solving when i want to sleep. it’s just so calming… but i always come back to finish watching it the next day
I made this.
In just under 40 min too. Very interesting idea for a puzzle.
38 mins for me. Thanks! Much easier than expected. After playing around quickly realized some of the constraints and it flowed quite easily for me....
Not a hugely important detail, but you can prove that anti-bishop is incorrect a bit sooner in the puzzle - as soon as you place the 3 in the corner, in fact - by looking at where 3 would go in box 1 if there was an anti-bishop constraint
Such a great puzzle. Very clever "setting". Loved it. 🙂
The amount of work the indeterminate anti-chess requirement in this instruction set (I refuse to call it a rule set) did to move the solve forward was astounding.
Such a well constructed puzzle. Every time I remembered to consider a rule it turned out to be exactly what I needed to make progress.
Genius construction. More proof that super intelligent aliens must be living among us.
I didn’t know I could set puzzles! 😅😂
This was fun. I had to clear out wild coloring multiple times because I kept confusing myself.
This is the best puzzle I solved. Simply amazing.
"I want 7 red perpendicular lines, 4 in blue ink, 3 in green ink..."
If anyone gets that reference, hats off to the expert ;-)
So now take all the numbers out but leave the lines, and then solve it again...
A creative meta-puzzle!
They should get Mark to solve it
You should really leave the given 3 as well.
It's really not a very interesting puzzle to solve. Oh well, perhaps Simon will get better at setting sudokus with more practice.
Done in 30:29, Simon *wildly* over thought this one. It was a delightfully straightforward yet brilliantly set solve path.
While I will never be able to solve this, I did get the sense Simon was overthinking it.
By my calculations, there are just over 10 million combinations of these rules, so I think Michael might be the single most prolific setter in history :P
That's why I made Simon figure it out for me. Couldn't be bothered.
Might be silly but I went back and solved the puzzle again, having all the clues. What a puzzle, me!
Too bad you didn't got told to open the link live. I so wanted to see your first reaction. At least it was a beautiful puzzle as always
Really enjoyed this puzzle, it's both fun to solve and has a cuteness to it. 68 minutes for me
Man this was the best construction I've had the opportunity to test out so far, it was very interesting trying to find out the constraints and how to use them properly to understand the grid.
And I'm glad it only took 32 minutes to do, but man was it so enjoyable, I found the German whisper constraint the easiest to find out, Then after that the Zipper line felt very natural, and so did the Thermo, the only thing that stumped me was the Arrow, however in the end when I had basically shoved in every possible value in the cells, there was only one place to place the arrow and the solution after that was very easy.
@56:35: "Do I get to sing if I'm constructing?" The mischievous nod that followed made me laugh outloud... :)
That is insanely good. I'm pausing the video at the rules to have a go.
Though I'm sure it violates the spirit of this puzzle, you can rule anti-bishop out by uniqueness from the beginning, since any anti-bishop puzzle would also qualify as anti-king.
After taking over 2 1/2 hours to solve IcyFruit's zipper line puzzle, I was a little bit gun shy taking on another solve that had a long video but glad I did. Excellent puzzle and in the end it took me 35:06. Now to watch the video. Still don't think I've recovered enough to watch the zipper line puzzle yet!
At 20:53, is it presumptuous for Simon to exclude the non-whisper vertical 5s from Michael's signature cells? It might be apparent later, but he doesn't really justify it here.
yes, it is a mistake. it could well have fitted above.
I was also thinking about it. But it actually is impossible given the horizontal whispers couldn't be in row 9
If we try and put the vertical whispers in column 9, the horizontal whispers have to share a 4 or a 6 as a common digit. And that would only be possible in r1c9, making r1c8 and r2c9 the same digit
The ruleset reminds me of a sudoku supposedly made by a colorblind setter in which all the "colored" lines were grey. I checked that it was actually made by the same person.
❤
Brilliant job Michael. Brought a real smile to my face. 😅