After the week I've had working on this thing, it's delightful to be able to relax at watch it solved. :) And yes, it absolutely was a Cream reference... the first named version of this exploration (way back at 26 caged cells) was called Derek and the Dominos (being entirely two-cell cages), and I took to naming the whole progression after Clapton bands and songs.
I cannot tell you how much I approve of Derek and the Dominos. Layla And Other Assorted Love Songs remains my favourite album of all time :) Oh and by the way, what you've created here is one of the most incredible sudokus of all time!!!!
@@scottmsul they're really difficult to spot. There are puzzles in the apps where you pretty much have to use them. I'm still stuck finding a cell, trying out the options and seeing what happens next. I recently did one of the new domino puzzles in the cracking the cryptic app and that had digits that you knew propagated around the grid so that "this can't be 3, because either it sees 3 in the row or the column"
@@scottmsul This was the trickiest logic step for me as well. I looked for a *bent triple,* I did not find it, and eventually managed to rule *6* out of *r3c4* by just testing the effect of *r3c4 = 6.* I do not realy know how I was able to identify that cell as a weak spot, but I studied other *bi-value cells* for several minutes before spotting that one.
This is a masterpiece. The brilliance of it is that it looks nearly impossible to solve at the outset, yet no advanced techniques are involved in the solution. It’s actually very approachable.
@@alainculos9294 I've forgotten everything I ever knew about classic Sudoku and was never good at bent triples to begin with, but lucked into finding a 36 cell that was always a 3 after inspecting the grid for a while. Chain wasn't ridiculously long, I'll take it.
After having had the great fortune to be one of the first people to test this one over on the Discord when it appeared yesterday, I've been saying that everyone needs to try this "clearly impossible construction." I have never been less surprised to a puzzle get on to the channel this quickly. It's just such an astounding construction. And, Simon's reaction to seeing the grid is everything I could have hoped it would be. Even having been following the quest for minimal killers, I couldn't quite believe it myself before I solved it. Philip is truly a mad genius.
The "Miracle Sudoku" by Mitchell Lee was my introduction to this wonderful channel, and this video showcases the same qualities that have me hooked ever since: Simon's utter joy at the unfolding beauty, and the way you seemingly effortlessly perform marvellous feats of logic AND explain them in an understandable and entertaining way. Thank you so much for sharing this with the world!
Ridiculous. Legit stunned. I have no idea how long it took me because I paused the timer to read the rules like six times, being like "that's it"?? But then I saw something in the grid and started typing and all of a sudden it was done and I was so engrossed I'd forgotten to start the timer! Absolutely genius. So flipping cool
I watched Philip take the journey of finding/setting this puzzle on the discord and the payoff is so much more than anyone expected! Practically everyone thought the minimum cell coverage must be somewhere around the mid-20s, and the idea of finding anything close to 18 was laughable! I don't blame you for thinking you were trolled, because the fact that this puzzle exists is extraordinary on its own. But it also has such a great solve path? Definitely one for the Sudoku history books! And yes, the search goes on for a 17 cell coverage puzzle :)
Over 50,000 regular sudokus with only 17 cells have been found. Each can be converted to a killer sudoku with only 17 cells, by putting one cage round each number!
@@gilesbrennand7529 Well, not each one, because not all of them can be morphed to have the givens adjacent in such a way that a cage can be drawn. It's certainly an area to explore, though.
@@Rangsk I think GIles meant having the givens as one cell cages, so you basically transform regular givens into pseudo killer cages to get a killer with 17 cells coverage. And yes, I do expect that to have been a joke, because you can't really call that a killer sudoku then.
Killer Sudoku cages do so much more than just plain digits. My guess is you can go lower than 17. Maybe much lower? There's so much more logic they imply
@@guycomments This is simply untrue. Consider that there's a puzzle where only 16 cells are covered by killer cages and solves uniquely. Take that and fill the cages with given digits from that unique solution. Do you agree that given digits in every cell covered by cages is strictly more information than just having the cages? It must be, because the only thing the cages tell is is something about the value of the covered digits, and putting givens there tells you more. Given digits in all the cages will tell you that there can't be repeats, because they don't repeat, and it tells you the sum because you can add them up. In addition to that, it tells you exactly what combination is used for the sum and the order that they go in. This is significantly more information. So, now you can remove the cages and not lose any information, and you have a 16 given classic sudoku that solves uniquely. We know this is impossible, so the lower bound for cage cell coverage to solve uniquely is 17. Since this video was released, on the Discord we've proved that no known 17 given puzzle can solve uniquely when replaced with killer cages, so it's not a proof, but we're pretty convinced that 18 is in fact the minimum.
I usually watch these as "backround noise" while I'm doing other things. But this one I was sitting with my hands on my headshaking it going "This is just insanity". This and the other miracle sudokus just completely blow my mind
I got to the point at the end with everything penciled in, but could not spot the bent triple. I ended up just testing out the 3 in box 8 to see if it would break, and when it didn't break, I realized the puzzle was just solved at that point. I have some work to do learning to spot those bent triples. Still a very fun puzzle to play.
I admit I don't watch the videos where people explain how they set their Sudokus but in this case i WANT to know how Mr Newman came up with this. The way the 89 pairs spread around the grid was like watching a flower bloom. What a masterpiece!
I really liked this puzzle. It took a hair less than an hour, but calling this a "white" room is a real misnomer. My puzzle looks like a rainbow exploded onto it.
I would love to see a video with a compilation of bloopers... The broken sudokus and pranks that you've been playing on each other because in a bunch of videos you say that the video won't air... Would love to see those that DON'T air... And ofc, the phone calls after the broken videos!
I've been watching the channel for a very long time and I think this easily becomes one of the top 5 mind-blowing puzzles I have seen. If we had a category for the best approachable puzzle for the average solver it would be hard not to make this #1.
That bent triple at the end made me think I had broken the puzzle somehow as I couldn't spot it at all... Beautiful solve, and thanks to Simon for pointing out the solution!
It took me close to 30 minutes to get to the idea of coloring 89s. For Simon it took like 3 seconds. When I watched the video, I could not believe how fast he got the right idea and was on the right path. Truly remarkable sudoku.
Ive been watching CTC for over a year. I found it really calming early in the pandemic when I was bored and stressed all the time. This was the first puzzle that i was able to solve without the video! Beautiful logic to it!
The sheer abject horror and disjoy that Simon felt when he first glanced at the Sudoku, compared to the love for the puzzle when he solved it, that is truly the best part about watching Simon's solves. The sheer disbelief contra the bafflement of it being solvable. Truly what makes a masterpiece.
I can't stop crying at how beautiful this solve was. Just so elegant. I feel like this is the point in which sudokus act more as poetry than puzzles. Bravo Simon on another flawless victory
Eurgh, those Y-wings/bent triples are the bane of my sudoku existence. I cannot for the life of me spot those things! Anyway, amazing puzzle and just a joy to watch. Well done!
Sublime puzzle! Despite having such low info, it has a very natural solve path, which makes it very fun and not too hard. It has become one of my favourites featured on this channel.
As a Killer Sudoku fan, I am quite used to starting off with no digits. But with such a paucity of cages? WOW -- Kudos to both the setter and the solver, what a joy!
Oh, wow! Something I love - I solved this in the opposite order, tracing down where 12s could go before I attacked the 89s. And it's no less beautiful through that route! (Maybe even more so - you get that startled "wait, did I just constrain both colors almost completely on the grid?!" feeling _twice_) Philip, you are a master. This was great!
16:14 for me. What an amazing puzzle, so few clues and the way they all work together. I would love to watch a ‘How I set sudoku’ video on this one in particular. Even if it’s not one of the most difficult ones we’ve seen lately, it’s one of the most impressive imo.
This is one of the rare puzzles I could actually complete. Took me many hours, and a few redos, but I finally got it. It is crazy how any information can be deduced, let alone the entire grid. But it somehow has a way even I can see.
Simon: ".. this is futile", "I'm not going to say solvable, because it simply isn't " ... then proceeds to solve the puzzle! Absolutely incredible solve and an incredible puzzle. A joy to watch!
First time I'm trying to solve a sudoku from this channel, I now totally understand the joy of cracking them. When pieces start falling into place, it's so elegant! Thanks for sharing these.
40:54, didn't see the bent triple, did it with bifurcation except that I didn't prove the negative, just got lucky with the puzzle solving. I enjoyed the break in not being the 5 and 6 cages, which is what I assumed.
Sudoku techniques must be sinking into my brain via osmosis or something, because near the end I was thinking "I bet he needs to look for a bent triple here" without knowing enough about them to spot where it was myself!
Actually, at this point in the puzzle we know that there is no anti-knight constraint, because two of the purples are a knight move away from each other.
I'm by no means good at sudoku, but I managed to solve it after trying for over an hour. It's a really beautiful puzzle. The only reason it took me that long is that I'm so slow to spot the logic, and that I make mistakes pretty often. It came together very nicely whenever I did spot the next step. Lots of parity logic which has to be my favourite.
It's funny--this is the first puzzle on this channel I've been able to solve completely on my own, and from the get-go I was really intrigued by the way the cages interact. I started off the way Simon did with the high-value cages, which yields all the eights and nines, but then I was drawn to the low-value cages. The way they interact with each other, competing for the low-value digits, was how I eventually got enough digits in to solve the rest of the puzzle.
I got stuck and couldn't find the bent triple! It's pretty funny that in the end the "hardest" part of this puzzle was just solving a classic sudoku. :D
I’m so happy. I’ve not completed a single puzzle on this channel but this is by far the closest I’ve come. I got as far as Simon did before he found the bent triple. Really good to watch after I got stuck. Well done Simon and thank you
I’ve been watching your channel without fail since the beginning of the pandemic, and this is the most extraordinary puzzle you’ve featured. It literally brought tears to my eyes. It opened up a portal in my brain, with regards to understanding sudoku. Because it’s not monstrously difficult, I hope it’ll have the same effect on others, who give it a go. Take a bow, Phillip. You’ve developed a masterpiece.
After watching the video for 10 min I decided to give this sudoku a try and with that help of colouring I was able to solve the puzzle in less than an hour.
What a sublime puzzle! Ive been watching for well over a year now and this is easily top 3. I did the logic on 1s and 2s first. The virtual x-wing works just as well without any cells being populated by high numbers. When watching Simon's solve I thought I had missed a lot easier path, but finally he had to find it too. It's interesting that you have to come from both sides to narrow things down. And the order in which you proceed is irrelevant. Great puzzle and great solve! Thanks to Philipp and Simon.
This really was an incredible puzzle, and it was neat to see how the logic flowed once you got started. I'm glad to see that Simon's solve of the puzzle went much more smoothly than mine because I had to restart this puzzle about 5 times because of careless mistakes on my part. But I guess that just made solving it correctly all the more satisfying. I even spotted the Y-wing near the end, and I'm usually bad at finding those.
Absolutely beautiful puzzle. It looked utterly impossible at first but... it wasn't actually that hard because it flowed so well, so elegantly. It still took me an hour but about 20 minutes of that was disambiguating 3456s with classic sudoku that I'm terrible at.
I really enjoyed solving this one! I found it easy, then hard, then easy, then hard.. Quite a roller coster of emotions! Now let's learn by watching Simon
I went through Gordon Royle's list of 50k different 17-clue sudokus. Only 3 of them were such that the clues all formed orthogonal regions of size at least 2, and none of them were unique for any way of making them into cages. However, it is still possible for such a sudoku to exist, since the 50k sudokus can be permuted in various ways that doesn't respect the orthogonality relation, and there may be other 17-clue sudokus not on the list.
This was just *amazing*, really. And I'm wrinting this before even watching the video. Took me a while to realize I should do something with 8s and 9s (instead of a complicated relation between all the 5,6 and 7 cages), and I couldn't believe how everything worked from there. Absolutely brilliant, bravo!
I remember seeing the Numberphile video with James Grime years ago about how you can't have a classic Sudoku with less than 17 clues, but I think these killer cages actually provide more information. Because in a classic Sudoku the digits are just digits, any set of nine symbols would do, but because killer cages use sums, that means the ordering of symbols does matter, the digits have an identity outside of just being nine things. So in any Sudoku variant that relies on sums there's inherently more information.
Killer cages do not provide more information relevant to solving a sudoku. What they do is eliminate the exchange symmetries that let you transform one valid grid into another by relabeling the digits (i.e. turning all the 1s into 9s and vice-versa or any other such swap). But, if you could validly perform that swap on a classic sudoku without affecting any of the givens, that puzzle wouldn't have a unique solution.
Imagine there was a killer sudoku that uniquely solved with only 16 cells covered. Well, you could just take that unique solution and replace the cages with the digits that ended up in those cages. This is strictly more information, and would produce a 16 given classic sudoku that uniquely solves. Since that is proven to not exist, it means that the absolute minimum coverage for killer cages is also 17 cells.
Y wings are just one of those things you get more natural at spotting when you do more of them. They're a relatively rare trick so it's hard to get used to them.
The CTC Classic Sudoku app has a whole bunch of puzzles in the middle difficulty ranks that need Y-wings as their final step - I struggled a lot to start with, but it was a great way to get practice at finding them because you'd be presented with a grid that just had loads of two candidate cells and just needed a Y-wing to crack the rest of the solve open. The scanning process for me begins with looking at cells that have only two candidates. When you find one, you then check its row, column, and box for any other two-candidate cells that share one (but not both) of those candidates. At that point, you have a potential Y-wing. Now you identify the pair of candidates between them that aren't shared (e.g. if your first cell was a 12 and then you found a 23 that it can see, they share a 2 so the pair of missing candidates is a 13). You're now searching the rows, columns, and boxes of your two cells for anywhere that one of them can see a cell that has just the missing candidates. If you find one, congratulations, you've got a Y-wing - now check if the two wings see any common cells and whether eliminating their shared digit actually helps (some of the higher difficulty puzzles in the app have Y-wing setups that don't actually eliminate anything, and I get sad everytime, haha). As you do this more often, the scan will start to get faster - one thing that helps is remembering which two candidate cells actually exist in your grid so you know what likely Y-wing combos exist and which cells not to even bother checking. But, fundamentally, the logic is still the same - find those first two two candidate cells that share a candidate, identify what cell they'd need to see in order to complete the Y-wing, then check if either of them can see that cell anywhere.
Never got so excited for a puzzle. Amazing work Simon, I love how you make us enjoy and Feel your emotions. Also greetings to the creator of this minimalistic masterpiece
I tried to solve this when i saw it on discord, and found myself with a schrodinger cell when coloring 12 pairs. This was based on some I'm assuming faulty logic regarding the cages along rows 2 3 and 4 which i decided had virtual 12 pairs throughout the rows
24:30 at this stage i'd decolor the grid and start coloring three-five pairs, cause i can tell you can do a lot of that, and it might force disambiguation
That’s how I finished it from that position - colour the 3/5’s in the bottom 3 boxes, you can show that in box 8 the 3 is in c5, giving r3c4 and the whole thing unwinds from there.
I rather enjoy the fact that it looked impossible, but when taking the right steps and following the right clues, it didn't take Simon very long to solve. The beauty of looking difficult but doesn't break the brain.
The difficulty of this one was a little up and down for me. The part at the end where Simon ends up finding that two possible 4s look at one square, I honestly just ended up bifurcating, despite spending a long time trying not to. Good spot by Simon on finding a spot in the grid that could be looked at logically.
Please, you simply must prostrate yourself before Mr. Newman and plead with him for a video on how he set this. It's magnificent. To see how he slowly shaved off digits to create nearly the most minimal and elegant killer sudoku imaginable would be fascinating.
After the week I've had working on this thing, it's delightful to be able to relax at watch it solved. :)
And yes, it absolutely was a Cream reference... the first named version of this exploration (way back at 26 caged cells) was called Derek and the Dominos (being entirely two-cell cages), and I took to naming the whole progression after Clapton bands and songs.
I cannot tell you how much I approve of Derek and the Dominos. Layla And Other Assorted Love Songs remains my favourite album of all time :) Oh and by the way, what you've created here is one of the most incredible sudokus of all time!!!!
This is one of the most amazing sudokus I've ever seen.
I wonder if this will start a race to find a unique 7 cage solution
The big thing you've done is that Simon now owes us a Clapton intro (2:38)
this was without a doubt one of the best solves ive seen on here. bravo. bravo.
My favorite puzzles. "This is impossible. I'll give it a few minutes."
The funniest part is that in the span of a few minutes he already discovered all nine of the 8s and 9s.
Same
@@frackingfluidinjection lol was true in mine
That sentence was half-correct.
Top 5 compliments Simon can give
5. Clever
4. Beautiful
3. Extraordinary
2. I almost cursed there
1. I’m pretty sure there’s a knights move missing
"This isn't going to solve"
"Surely this puzzle was sent in error"
6. Ridiculous
@@tessabrisac7423 7. Impossible
8. "I don't believe it"
simply stunning, gorgeous
I'm so proud of Simon for not swearing, even under extreme provocation. Not a single "Bobbins!" escaped his lips, and our children are safe.
I swear (pun intended) there was a jump cut in there just after which he claimed he had 'almost' cursed.
Best comment EU
22:17 i thought he dropped an F bomd there lol replayed it like 5 times lol
Is bobbins a bad word? I thought is was something to put in a sewing machine 😂
It sounds so innocent and nice
@@biaberg3448 bobbins is not sweating. I think op was exaggerating ;)
23:50 "This might be where it gets tricky." Yes, Simon. Totally straightforward before that.
This is where I got stuck haha, never even heard of a bent triple
@@scottmsul they're really difficult to spot. There are puzzles in the apps where you pretty much have to use them. I'm still stuck finding a cell, trying out the options and seeing what happens next. I recently did one of the new domino puzzles in the cracking the cryptic app and that had digits that you knew propagated around the grid so that "this can't be 3, because either it sees 3 in the row or the column"
@@scottmsul This was the trickiest logic step for me as well.
I looked for a *bent triple,* I did not find it, and eventually managed to rule *6* out of *r3c4* by just testing the effect of *r3c4 = 6.*
I do not realy know how I was able to identify that cell as a weak spot, but I studied other *bi-value cells* for several minutes before spotting that one.
This is a masterpiece. The brilliance of it is that it looks nearly impossible to solve at the outset, yet no advanced techniques are involved in the solution. It’s actually very approachable.
I agree, this is indeed a masterpiece. A beautiful solve, mostly "approachable", got stuck at the last post with the "bent" triple.
@@alainculos9294 I've forgotten everything I ever knew about classic Sudoku and was never good at bent triples to begin with, but lucked into finding a 36 cell that was always a 3 after inspecting the grid for a while. Chain wasn't ridiculously long, I'll take it.
Simon: Declares the puzzle impossible
also Simon: Proceeds with the intro anyway
After having had the great fortune to be one of the first people to test this one over on the Discord when it appeared yesterday, I've been saying that everyone needs to try this "clearly impossible construction." I have never been less surprised to a puzzle get on to the channel this quickly. It's just such an astounding construction.
And, Simon's reaction to seeing the grid is everything I could have hoped it would be. Even having been following the quest for minimal killers, I couldn't quite believe it myself before I solved it. Philip is truly a mad genius.
The "Miracle Sudoku" by Mitchell Lee was my introduction to this wonderful channel, and this video showcases the same qualities that have me hooked ever since: Simon's utter joy at the unfolding beauty, and the way you seemingly effortlessly perform marvellous feats of logic AND explain them in an understandable and entertaining way. Thank you so much for sharing this with the world!
My thoughts exactly :)
What a puzzle with which to start!
I've already told Philip that I think he's an utter madman. After watching this video, I will tell him so again.
he really is incredible!
Blown away here. This is the most elegant minimalist sudoku I've ever seen!
Ridiculous. Legit stunned. I have no idea how long it took me because I paused the timer to read the rules like six times, being like "that's it"?? But then I saw something in the grid and started typing and all of a sudden it was done and I was so engrossed I'd forgotten to start the timer! Absolutely genius. So flipping cool
I watched Philip take the journey of finding/setting this puzzle on the discord and the payoff is so much more than anyone expected! Practically everyone thought the minimum cell coverage must be somewhere around the mid-20s, and the idea of finding anything close to 18 was laughable! I don't blame you for thinking you were trolled, because the fact that this puzzle exists is extraordinary on its own. But it also has such a great solve path? Definitely one for the Sudoku history books!
And yes, the search goes on for a 17 cell coverage puzzle :)
Over 50,000 regular sudokus with only 17 cells have been found. Each can be converted to a killer sudoku with only 17 cells, by putting one cage round each number!
@@gilesbrennand7529 Well, not each one, because not all of them can be morphed to have the givens adjacent in such a way that a cage can be drawn. It's certainly an area to explore, though.
@@Rangsk I think GIles meant having the givens as one cell cages, so you basically transform regular givens into pseudo killer cages to get a killer with 17 cells coverage. And yes, I do expect that to have been a joke, because you can't really call that a killer sudoku then.
Killer Sudoku cages do so much more than just plain digits. My guess is you can go lower than 17. Maybe much lower? There's so much more logic they imply
@@guycomments This is simply untrue. Consider that there's a puzzle where only 16 cells are covered by killer cages and solves uniquely. Take that and fill the cages with given digits from that unique solution.
Do you agree that given digits in every cell covered by cages is strictly more information than just having the cages? It must be, because the only thing the cages tell is is something about the value of the covered digits, and putting givens there tells you more. Given digits in all the cages will tell you that there can't be repeats, because they don't repeat, and it tells you the sum because you can add them up. In addition to that, it tells you exactly what combination is used for the sum and the order that they go in. This is significantly more information.
So, now you can remove the cages and not lose any information, and you have a 16 given classic sudoku that solves uniquely. We know this is impossible, so the lower bound for cage cell coverage to solve uniquely is 17.
Since this video was released, on the Discord we've proved that no known 17 given puzzle can solve uniquely when replaced with killer cages, so it's not a proof, but we're pretty convinced that 18 is in fact the minimum.
"Sudoku guy reacts to: Puzzle" - That cracked me up :D
Now I feel the need to watch "Sudoku guy reacts to" every other reaction video I've ever clicked. And some more, like Maru vs Reynor xD
@@asbjrnfossmo1589 "Let's have a look at the APM... Absolutely bonkers."
I usually watch these as "backround noise" while I'm doing other things. But this one I was sitting with my hands on my headshaking it going "This is just insanity". This and the other miracle sudokus just completely blow my mind
I got to the point at the end with everything penciled in, but could not spot the bent triple. I ended up just testing out the 3 in box 8 to see if it would break, and when it didn't break, I realized the puzzle was just solved at that point. I have some work to do learning to spot those bent triples. Still a very fun puzzle to play.
I admit I don't watch the videos where people explain how they set their Sudokus but in this case i WANT to know how Mr Newman came up with this. The way the 89 pairs spread around the grid was like watching a flower bloom. What a masterpiece!
Fr tho
I really liked this puzzle. It took a hair less than an hour, but calling this a "white" room is a real misnomer. My puzzle looks like a rainbow exploded onto it.
I really liked it up until i got stuck finding the broken triple grrr. luckily I had a video to cheat with.
I would love to see a video with a compilation of bloopers... The broken sudokus and pranks that you've been playing on each other because in a bunch of videos you say that the video won't air... Would love to see those that DON'T air... And ofc, the phone calls after the broken videos!
These would make a perfect 1'st April videos.
At 8:09: "I haven't actually got a digit placed."
6: Am I a joke for you?
Why was it a six there and not in one of the other two spots in the 23 cage? Why wasnt the 23 cage a 689 triple?
@@alpha1481 The 17 cage right below it is an eight nine pair, which means there can't be another eight or nine in the column
Ah. Thanks King!!
I've been watching the channel for a very long time and I think this easily becomes one of the top 5 mind-blowing puzzles I have seen. If we had a category for the best approachable puzzle for the average solver it would be hard not to make this #1.
Agreed, I am kinda new to this and managed to do it. It took a while and I hit a few walls, but in the end it gave way.
Indeed! Too bad it cannot make it into the book... Part 2 maybe?
i agree it's pretty outstanding! normally i don't consider killers to be approachable, but this one is perfect
To me this is absolutely stunning. Mainly because the lack of restrictive rules, such as knights move, that are usually part of minimalist puzzles.
When Simon almost swears, you know it’s going to be a great video haha
Do you have a timestamp? I didn't pay attention to that :(
@@richy77 1:25 (he just said that he almost swore) and another time a few minutes later :)
@@pandaspangel ah I see thanks
Can’t believe he almost said the word bobbins, and ruined my Sunday morning
@@skarcade Hah! If it was ‘bobbins’ he wouldn’t have stopped himself, since we all love it so much
It took me over 2 hours, but I managed this one! Wohoo! The first non-GAS one I have solved without any clues.
Same here! Well done.
it honestly baffles me how people set these sudokus
This has got to be one of the most beautiful puzzles ever constructed.
That bent triple at the end made me think I had broken the puzzle somehow as I couldn't spot it at all... Beautiful solve, and thanks to Simon for pointing out the solution!
It took me close to 30 minutes to get to the idea of coloring 89s. For Simon it took like 3 seconds. When I watched the video, I could not believe how fast he got the right idea and was on the right path. Truly remarkable sudoku.
Ive been watching CTC for over a year. I found it really calming early in the pandemic when I was bored and stressed all the time. This was the first puzzle that i was able to solve without the video! Beautiful logic to it!
The sheer abject horror and disjoy that Simon felt when he first glanced at the Sudoku, compared to the love for the puzzle when he solved it, that is truly the best part about watching Simon's solves. The sheer disbelief contra the bafflement of it being solvable. Truly what makes a masterpiece.
That's absolutely incredible. What an idea, it just didn't look possible at all at first.
A genuine classic. Brilliant puzzle that solves in less than 30 minutes. Recipe for a viral video.
Absolutely--this puzzle deserves to go viral!
This was perhaps the best sudoku I have ever come across. I wonder how Philip pulled it off. Simon's expressions while solving it was priceless.
I can't stop crying at how beautiful this solve was. Just so elegant. I feel like this is the point in which sudokus act more as poetry than puzzles. Bravo Simon on another flawless victory
I would never have solved this puzzle without Simon's knowledge-bomb about "bent triples". Proud that I got to that point without any help though.
Eurgh, those Y-wings/bent triples are the bane of my sudoku existence. I cannot for the life of me spot those things! Anyway, amazing puzzle and just a joy to watch. Well done!
Wow! Thank you, Philip!! And thank you, Simon!
Sublime puzzle! Despite having such low info, it has a very natural solve path, which makes it very fun and not too hard. It has become one of my favourites featured on this channel.
That's why they label them "miracle" sudokus :-)
As a Killer Sudoku fan, I am quite used to starting off with no digits. But with such a paucity of cages? WOW -- Kudos to both the setter and the solver, what a joy!
This puzzle was the first grid without any given digits I was able to solve (with a little help from Simon)! I had a blast solving it!
Wow. Just wow. This. Is. Mad. Mad setting skills, mad minimalism, mad beautiful sudoku. Simply amazing.
The sheer sense of wonder during the solve was such a joy.
You did indeed do it justice.
Oh, wow! Something I love - I solved this in the opposite order, tracing down where 12s could go before I attacked the 89s. And it's no less beautiful through that route! (Maybe even more so - you get that startled "wait, did I just constrain both colors almost completely on the grid?!" feeling _twice_)
Philip, you are a master. This was great!
Oh, man, I can't believe that! Have you got this in video! Send it to us!
16:14 for me. What an amazing puzzle, so few clues and the way they all work together. I would love to watch a ‘How I set sudoku’ video on this one in particular. Even if it’s not one of the most difficult ones we’ve seen lately, it’s one of the most impressive imo.
It’s been about four months since this video was published. Had to go back and watch it. Incredible puzzle and incredible solve
Took me an hour - possibly one of the best puzzles I have done and completed.
This is one of the rare puzzles I could actually complete. Took me many hours, and a few redos, but I finally got it. It is crazy how any information can be deduced, let alone the entire grid. But it somehow has a way even I can see.
Absolutely stunning. Took me 61:40, but that was time well spent. Wow!
That final XY-Wing was so satisfying. Great video.
Simon: ".. this is futile", "I'm not going to say solvable, because it simply isn't " ... then proceeds to solve the puzzle! Absolutely incredible solve and an incredible puzzle. A joy to watch!
I enjoy watching these puzzles being solved but have never been caught up in the actual marvel of the puzzle until this one. Well done.
This video should be set to “Thus Spake Zarathustra” as Simon slowly realizes that this beauty is solvable.
What a joy to solve! I was daunted by the intro but gave it a go - so glad I did. I was so pleased when I got the 7 in box nine
this has been one of the best puzzles I've ever seen
i love killer sudoku and to see such a simple grid was a joy
First time I'm trying to solve a sudoku from this channel, I now totally understand the joy of cracking them. When pieces start falling into place, it's so elegant! Thanks for sharing these.
40:54, didn't see the bent triple, did it with bifurcation except that I didn't prove the negative, just got lucky with the puzzle solving.
I enjoyed the break in not being the 5 and 6 cages, which is what I assumed.
Sudoku techniques must be sinking into my brain via osmosis or something, because near the end I was thinking "I bet he needs to look for a bent triple here" without knowing enough about them to spot where it was myself!
This is so amazing. Though it's relatively simpler than most of the other ones on the channel, it never fell short of being very elegant.
"I haven't needed a knight's move yet" - Is this the sudoku equivalent of PTSD flashbacks?
Actually, at this point in the puzzle we know that there is no anti-knight constraint, because two of the purples are a knight move away from each other.
"and these bent triples... are they in the room with us now?"
I'm by no means good at sudoku, but I managed to solve it after trying for over an hour. It's a really beautiful puzzle. The only reason it took me that long is that I'm so slow to spot the logic, and that I make mistakes pretty often. It came together very nicely whenever I did spot the next step. Lots of parity logic which has to be my favourite.
I couldn't believe that this one has a solution and I managed to solve it without watching Simon. What an amazing puzzle!
OMG, the coloring thing for pairs is actually genius. I have to try it.
I solved it in 45 minutes, and I'm not sure how. It was like the setter was pushing me forward the entire time towards the solution.
It's funny--this is the first puzzle on this channel I've been able to solve completely on my own, and from the get-go I was really intrigued by the way the cages interact. I started off the way Simon did with the high-value cages, which yields all the eights and nines, but then I was drawn to the low-value cages. The way they interact with each other, competing for the low-value digits, was how I eventually got enough digits in to solve the rest of the puzzle.
7:58 - "I haven't needed the knight's move yet" - good, because the purples would be broken by now!
I got stuck and couldn't find the bent triple! It's pretty funny that in the end the "hardest" part of this puzzle was just solving a classic sudoku. :D
Being able to spot the same bent triple/Y-wing as Simon (albeit much slower) is such a rush.
I’m so happy. I’ve not completed a single puzzle on this channel but this is by far the closest I’ve come. I got as far as Simon did before he found the bent triple. Really good to watch after I got stuck. Well done Simon and thank you
I’ve been watching your channel without fail since the beginning of the pandemic, and this is the most extraordinary puzzle you’ve featured. It literally brought tears to my eyes. It opened up a portal in my brain, with regards to understanding sudoku. Because it’s not monstrously difficult, I hope it’ll have the same effect on others, who give it a go. Take a bow, Phillip. You’ve developed a masterpiece.
This is my favorite ever "no digits" puzzle!
After watching the video for 10 min I decided to give this sudoku a try and with that help of colouring I was able to solve the puzzle in less than an hour.
What a sublime puzzle! Ive been watching for well over a year now and this is easily top 3.
I did the logic on 1s and 2s first. The virtual x-wing works just as well without any cells being populated by high numbers.
When watching Simon's solve I thought I had missed a lot easier path, but finally he had to find it too.
It's interesting that you have to come from both sides to narrow things down. And the order in which you proceed is irrelevant.
Great puzzle and great solve! Thanks to Philipp and Simon.
What a discovery. I got stuck at the very end, not able to spot the bent triple, but otherwise the logic flowed very naturally
This really was an incredible puzzle, and it was neat to see how the logic flowed once you got started. I'm glad to see that Simon's solve of the puzzle went much more smoothly than mine because I had to restart this puzzle about 5 times because of careless mistakes on my part. But I guess that just made solving it correctly all the more satisfying. I even spotted the Y-wing near the end, and I'm usually bad at finding those.
What an extraordinary puzzle!! Thank you Philip and Simon for great entertainment.
I was wondering what purpose the colors served. This opened up a new strategy for me on the expert level puzzles. Thank you!
I am always delighted when you explain bent triples. Very nice puzzle, solved in an impressive way!!! Thx!
Absolutely beautiful puzzle. It looked utterly impossible at first but... it wasn't actually that hard because it flowed so well, so elegantly.
It still took me an hour but about 20 minutes of that was disambiguating 3456s with classic sudoku that I'm terrible at.
I really enjoyed solving this one! I found it easy, then hard, then easy, then hard.. Quite a roller coster of emotions!
Now let's learn by watching Simon
Makes one wonder if there exists a uniquely specified killer sudoku with 17 caged cells!
And all of them at least two cells, otherwise 17 cages of size 1 is a degenerated case.
I went through Gordon Royle's list of 50k different 17-clue sudokus. Only 3 of them were such that the clues all formed orthogonal regions of size at least 2, and none of them were unique for any way of making them into cages. However, it is still possible for such a sudoku to exist, since the 50k sudokus can be permuted in various ways that doesn't respect the orthogonality relation, and there may be other 17-clue sudokus not on the list.
Love to see that simple-ruled puzzles can be amazing.
Totally!
I enjoyed this one so much that I had to go back and watch it again!! I love Simin’s reaction throughout the whole puzzle!!
This was just *amazing*, really. And I'm wrinting this before even watching the video. Took me a while to realize I should do something with 8s and 9s (instead of a complicated relation between all the 5,6 and 7 cages), and I couldn't believe how everything worked from there. Absolutely brilliant, bravo!
An absolutely outrageous puzzle; absurd, in fact. Fantastic work by Philip Newman. Can we have a setter's video for this masterpiece?
Just unbelievable brilliance by both Phillip and Simon! Such a compelling video!
I remember seeing the Numberphile video with James Grime years ago about how you can't have a classic Sudoku with less than 17 clues, but I think these killer cages actually provide more information. Because in a classic Sudoku the digits are just digits, any set of nine symbols would do, but because killer cages use sums, that means the ordering of symbols does matter, the digits have an identity outside of just being nine things. So in any Sudoku variant that relies on sums there's inherently more information.
Killer cages do not provide more information relevant to solving a sudoku. What they do is eliminate the exchange symmetries that let you transform one valid grid into another by relabeling the digits (i.e. turning all the 1s into 9s and vice-versa or any other such swap). But, if you could validly perform that swap on a classic sudoku without affecting any of the givens, that puzzle wouldn't have a unique solution.
Imagine there was a killer sudoku that uniquely solved with only 16 cells covered. Well, you could just take that unique solution and replace the cages with the digits that ended up in those cages. This is strictly more information, and would produce a 16 given classic sudoku that uniquely solves. Since that is proven to not exist, it means that the absolute minimum coverage for killer cages is also 17 cells.
Just started watching this, how is this ever going to be uniquely solvable. This must be a miracle indeed.
Edit: WOW ♥️
Goes from the puzzle being unsolvable, to solving it in under a half hour. Nicely done.
Love the reaction to it. Wanna experience a similar surprise someday…
I knew it was likely a Y-wing at the end but I just couldn't spot where. I love it as a technique but I'm still so bad at spotting them without help!
I was stuck for an hour at the end before I finally had to call it quits on the Y-wing.
Y wings are just one of those things you get more natural at spotting when you do more of them. They're a relatively rare trick so it's hard to get used to them.
The CTC Classic Sudoku app has a whole bunch of puzzles in the middle difficulty ranks that need Y-wings as their final step - I struggled a lot to start with, but it was a great way to get practice at finding them because you'd be presented with a grid that just had loads of two candidate cells and just needed a Y-wing to crack the rest of the solve open.
The scanning process for me begins with looking at cells that have only two candidates. When you find one, you then check its row, column, and box for any other two-candidate cells that share one (but not both) of those candidates. At that point, you have a potential Y-wing. Now you identify the pair of candidates between them that aren't shared (e.g. if your first cell was a 12 and then you found a 23 that it can see, they share a 2 so the pair of missing candidates is a 13). You're now searching the rows, columns, and boxes of your two cells for anywhere that one of them can see a cell that has just the missing candidates. If you find one, congratulations, you've got a Y-wing - now check if the two wings see any common cells and whether eliminating their shared digit actually helps (some of the higher difficulty puzzles in the app have Y-wing setups that don't actually eliminate anything, and I get sad everytime, haha).
As you do this more often, the scan will start to get faster - one thing that helps is remembering which two candidate cells actually exist in your grid so you know what likely Y-wing combos exist and which cells not to even bother checking. But, fundamentally, the logic is still the same - find those first two two candidate cells that share a candidate, identify what cell they'd need to see in order to complete the Y-wing, then check if either of them can see that cell anywhere.
I was starting to struggle and then, like Simon, I thought "let's break out the colours". Beautiful puzzle and really not that tricky.
Thank you
I wish I'd done coloring for the 89s, but instead gave up too early, figuring it was a crazy mind bender.
Never got so excited for a puzzle. Amazing work Simon, I love how you make us enjoy and Feel your emotions.
Also greetings to the creator of this minimalistic masterpiece
I tried to solve this when i saw it on discord, and found myself with a schrodinger cell when coloring 12 pairs.
This was based on some I'm assuming faulty logic regarding the cages along rows 2 3 and 4 which i decided had virtual 12 pairs throughout the rows
I so enjoy watching your delight in solving these!
24:30 at this stage i'd decolor the grid and start coloring three-five pairs, cause i can tell you can do a lot of that, and it might force disambiguation
That’s how I finished it from that position - colour the 3/5’s in the bottom 3 boxes, you can show that in box 8 the 3 is in c5, giving r3c4 and the whole thing unwinds from there.
Magnificent! That's the best one in last 2 years as for me
I rather enjoy the fact that it looked impossible, but when taking the right steps and following the right clues, it didn't take Simon very long to solve. The beauty of looking difficult but doesn't break the brain.
Mind blown!! by a mind blowing puzzle.
The difficulty of this one was a little up and down for me. The part at the end where Simon ends up finding that two possible 4s look at one square, I honestly just ended up bifurcating, despite spending a long time trying not to. Good spot by Simon on finding a spot in the grid that could be looked at logically.
Coloring the 4/6 pair in c8 helped a lot with that one at the end.
Please, you simply must prostrate yourself before Mr. Newman and plead with him for a video on how he set this. It's magnificent. To see how he slowly shaved off digits to create nearly the most minimal and elegant killer sudoku imaginable would be fascinating.