It's getting me through my second confinement evenings, as it did the first one's :) Feel free to browse the history of the channel, you have 2 puzzles a day for months.
Agreed, only found these during lock-down, never thought much of Sudoku, but it is impressive the way Mark and Simon tackle these, and the people who set them... well, hats off. Genius.
The thing that makes these videos brilliant is not just the logic, but the sheer joy you have at solving these intricate puzzles. There's something just so satisfying about watching that combination of talent and love of the game.
34:16 "Now there's probably loads of things we can see here if we're good at scanning." - Simon, not seeing he can immediately place a 2 in one of the three cells he just highlighted just by using normal sudoku logic
🤣🤣 Simon says "I'm so stupid" or "I'm sure you've all spotted the next move". He gives himself too little credit and too much to us 😁 The logic is beautiful though so I'm going to give it a bash for you. There are 2 lovely pieces of logic combining. r4c3 is a 2 in the final solution and one of the 4 red cells. We don't know it is a 2 yet. We do know that whatever it is there is a number that matches it in the middle box as all boxes contain all 9 digits. We also know that it is in the 25 cage, and that this rules it out of 3 of the squares in the middle box that are also in the 25 cage ( The 4, 9 and 7 squares in the finished solution ). We know it can't be in r6c4 ( 8 in the finished solution ) as this is in the same column. We know it can't be in r5c5 or r4 c6 ( 6 and 5 in the final solution ) because these are a knights move away. So we have 3 squares left where it can be in the middle box r5c6 r6c5 r6c6 ( 1, 3 & 2 in the final solution ) We also know that all 3 of these squares are in the 17 cage. So now we know that this number is in both the 25 cage and the 17 cage. This process can be repeated for the other 3 red squares forcing 4 numbers to be in both the 17 cage and the 25 cage ( I can run through all this too if you like ) There is now only 1 number left in both the 17 cage and the 25 cage that are not the same as each other. 25 - 17 = 8 So one of these digits is 8 larger than the other one. 1 + 8 = 9 If the smallest digit is larger than 1 then the largest digit has to be 10 or more. As this can't happen then the smallest digit has to be 1 and the largest digit 9. So there is a 1 in the 17 cage and a 9 in the 25 cage. Hope this helped. Hard to know where I'm overexplaining or underexplaining.
"It cannot be 12346.... Therefore, it has to be a 6 or a 8!" Absolutely GENIUS! Then again, It took me about an hour to figure stuff he wrote down in the first 15 minutes of the video :(
Being able to spot things like that help us feel slightly less idiotic as he goes through other things so speedily...for me it was waiting for him to notice the effect of the 9s in the 30 cage on the 9s in the 25 cage
It is amazing how many times in these solves you tell us that you are missing some piece of logic and then you move the mouse and randomly stop the cursor on the digit for which you are missing the logic. :) Your enthusiasm is infectious Simon! Thanks for brightening our days.
Maybe Simon I didn't love that puzzle as much as you, but it and watching your joy solving it did make me cry. I did love the puzzle. A knights move restriction tends to make puzzles easier thus even a Phistomefel puzzle was going to fall quickly.
I know they made their choices for the puzzles and the deadline has passed for the fan selections, but I am sure this puzzle would be in the book if it could be. Then again, there could always be a Volume 2 because of the success of this book.
We're many months away from shipping, surely they won't mind streching the deadline to include this one if they feel it's worth it. It would be in the benefit of everybody.
There is so much joy in this video I couldn't help but giggling like a little kid watching it even if I couldn't always follow the train of thought. Truly a joy to watch and an amazing puzzle to boot!
What a awesome sudoku and beautiful solving. I'm so happy that I found this channel. I spotted a negative constraint that makes me feel happy, too, since I am a beginner in sudoku: In 32:00 when you placed the 589 triple in box 7, the two cells in row 7 can not be a 59 pair, since that would clash with the 59 pair in box 4 because of the knight's move. So one of the two cells in row 7 has to be an 8.
I felt pretty proud to crack this one. I didn't get the nice logic with the two cages sharing the central box, but after working down the restricted cells adjacent to the cages a bit, I found that the 25 cage had to have 3 low digits and 2 high digits, which ended up cracking open most of the rest of the puzzle (I think it is roughly the same logically, but you start by finding the 6,8 in the center, rather than discovering the 1,9).
It's midnight. => Noticed a new Phistomefel puzzle on CTC. => Realized it's Sunday and needed to wake up in the morning for work. => Hmm. => Well let's enjoy the puzzle before sleep! I can live with a couple hours less sleep ;) ... This is a brilliant puzzle! The plus shape interacts nicely with the knight constraint. Took me 1h16 to finish it
A really amazing puzzle. I think it becomes much easier if you notice that each cell that is orthogonally ajacent to a +cage sees all the outer squares (and therefore the whole cage if it sees the central one as well).
The rare occasion when I've done a Phistomefel puzzle before you! I spotted the constraint of R3C4 on box 5, but I used it to rule digits out of R3C4 rather than into the box 5 cages, and my solve path was much longer. This is a far more elegant solution that allows me to see what the puzzle was meant to be. Thanks for covering it.
If I said that the man's a bloody genius, I wouldn't be telling anybody anything they didn't already know. But I'm going to say it anyway. The man's a bloody genius. That interaction between the cages and the knight's move to give you a difference of 8 in the non-shared digit, well, I agree with everything Simon said about it. Of course, I didn't spot it quite as quickly as Simon did. Puzzle took me hours but I stuck with it, and given that it's a Phistomefel puzzle managing to solve it at all isn't anything to be ashamed of. Absolutely worth it.
It was a brilliant puzzle. It was almost like he created it to play against your very few weaknesses. In this puzzle, you had to do a lot of pencil mark maintenance. If you are not careful it could have easily gotten confusing. Finding the break-in is your specialty who would even think of looking for that.
I've been waiting for so long to share this conjecture of mine, and now that I have a possible counterexample, here it is: My conjecture relates to the ability to split an n-tuple of sudoku pencil-marks into a smaller x-tuple and an (n-x)-tuple. It states that any n-tuple which does not have a way to be split it into any smaller x-tuple (there is no subset of the n-tuple with exactly x cells that contains exactly the same x digits in only the cells in that subset) must have a cyclic connection between its cells (for example, having a triple with cells {(1,2,6),(1,2),(2,6)}, numbered 1-3 in order written, we have a cyclic connection of cells 2->3->1 that goes[(1,2),(2,6),(6,1)]. The general pattern, with arbitrarily many cells, is an order such that an ordered pair of any two digits in the cell occurs so that the first in the pair is the second in the previous, while the second in the pair is the first in the next. The cell itself must have both pencil marks possible, and the last cell is followed by the first, as this is an ordered cycle) . As for the possible counterexample, look at the quadruple in column 6 in 27:23 on screen. It goes {(1,2,4,7),(1,2),(2,7),(2,4)}. I could neither find a smaller split in the quadruple nor a cyclic connection, so it seems to be a counterexample to my conjecture. An interesting question remains: Can this happen in a solvable classic? If not, what variants allow such a counterexample?
In my opinion Phistomefel is the best setter I’ve ever seen, the resolutions are always so elegant !! But hard too, I believe I’ve never been able to finish a single of his puzzles without help (the reason why I like to call him Fistomefel... hum)
Me - "Simon!! Why can't you see the threeee's?!" Simon - "Let me explain this other piece of beautiful logic you didn't see while you were shouting." Me (still shouting) - "Simon, you're a genius!!"
That was a really cool puzzle. I saw what looked like the break in as soon as it came up on screen and started working on it but had to go get dinner so it sat open for hours before I got back to finish it so no clue on my time but I imagine at least a couple of hours. Felt this one was easily understood.
Phistomefel is en route to drive Simon insane one day. It’s always entertaining to see Simon’s admiration and subsequent unraveling of Phistomefel’s genius Sudoku settings. Highly enjoyable cat and mouse game. :))
"I hope you enjoyed it a shadow as much as I did". In fact I "enjoyed" it FOUR times as much as you did, at least. Somewhere between 2 and 3 hours solving time for me, or 12 hours elapsed if you count sleeping. Didn't spot the quintuple in row 2 right from the start but managed to get the quintuples in the crosses by trial and error. Also did a lot of cancelling digits by knights move only (using colouring extensively). I took a screenshot and went to bed last night and came to finish it this morning. It was only 12 more minutes from the point I parked it overnight to finishing. Maybe I wish I'd stayed up a little more. On the other hand, fresh mind after a good sleep means it might have taken way more than 12 more minutes last night so it was probably the right thing to do! Super puzzle.
I never got to the 12:40 reveal, and I don't think I would have found it without peeking at the video. The geometry of this puzzle with knights moves is gorgeous. The entangled shapes make me think about the miracle sudoku 2's thermos.
at 34:37 i felt so smart cause i saw the restrictions with the 258 triplet. i only just started playing more difficult sudokus and it takes me multiple attempts with mistakes highlighted to finish them.
"You will never see another puzzle this beautiful," promises Simon for--what?--the twelfth time this month? XD So blessed to have such an amazing roster of setters that each puzzle is a mind-blower.
31:57, "Not used to things I can actually do." the entire audience whenever we watch him solve a killer sudoku with a knight's move and no givens and requires a sacrifice to Satan: "We know how you feel."
Bobbins! It is sooo *frustrating* when you feel like you get into the puzzle and make progress, even put in one or two digits, thinking you understood the "trick" of it - and then get completely bogged down. Had to give up after having 3 digits and a whole lot of pencil marks in the grid.. :/
I suspect the confusion with respect to R4C2 was because the cell directly above it had 1-2-3-4, so while you're obviously scanning and seeing the 6 you're focusing on the 1234 and.
You can get that central logic (that 4 digits are shared among 25 and 17 cage) in a different way. In the central box you have 3 cells that see all cells of both cages (in total 10 cells). This means that some digits in those cages have to shared, otherwise you wouldn't have any digit to put into those 3 cells. What's more in those cages you can use at most 6 (= 9-3) digits, because you need to have 3 digits left for those 3 cells in the center. So you have 10 cells that use at least 6 digit and each digit can used at most 2 times (once per each cage). The only way you can achieve this is by sharing (at least) 4 digits. So you have 4 digits that are used twice and 2 once (or 5 digits twice, but this is impossible, because cages have different sums). I also was trying to use this kind of logic for the plus cages, because a cell between two pluses also sees all 10 cells. In such case you get that cages share at least 2 digits.
I don't know why this one was so rough on me, but I know the mistake I made over and over. I kept at various points removing a possibility by what I was thinking was a knights move, but was actually doing a long-knights more (2 forward 1 diagonal). I have no idea why my brain kept doing this but after 4 restarts and 3 hours I finally got the correct solution. Just had to take it a lot slower on the final run. The logic was nice. Also amazing spot on that quad. I didn't see it. I ended up realizing that between the 17 cage and the 45 cell above it that the other non-cage cells in the central box couldn't be 1-3, 4, or 5, leaving 6-9. Then I looked at the possibilities for the 25 cage and realized that 2 of them used three of the 6-9 digits and therefore could not be used because that would force those two squares to be the same value. The remaining two possibilities allowed me to rule the 4 out of the 4-5 cell above the 17 cage which restricted the 17 cage which then restricted the 25 cage which then restricted the 30 cage after getting the 8 in the cell above it. I also played the 79 cell a bit earlier. One thing I did that was a little more convoluted was I looked at where 1s could go and quickly ruled out possibilities such that box 1 and box 4 had their 1s locked. That forced a 1 into box 7 column 3, which eliminated the possibilities further for box 8 down to two cells, box 2 down to 2 cells, and the 17 cage already had them limited in box 5. Then I locked them down to three possibilities in box 9 and a few (I forget how many) in box 6. Box 3 was already limited to the 8 cage as well. I forget what I did next, but one of the digits I was able to place next allowed me to completely unwind all the 1s, then the 6s and got me moving again. I think it had to do with the 17 cage, but after restarting 4 times my mind's a little fuzzy. Still an amazing puzzle. I did try his theorem a time or two, but the times I looked at it, it didn't provide any insight I didn't already have. I want a puzzle where his theorem is critical to solving the puzzle. One where no other technique (other than long chains, which you can't ever completely avoid, basically bifurcation at that point) will work. Can you give us one where your theorem is required? Please do! :)
this was a pretty nice puzzle. I wrote down all the combinations for 30 and 25 and couldn't get a unique 5sequence in each box, so the trick with the 2 cells out and in was what pushed it thought. I wasn't good enough to get it
At the 11:30 mark the way that I figured that out was I noticed that all three of the cells that were not in cages in the central box saw every single cell of both cages and therefore must contain digits that could be left out of both cages. The 17 cage only has two possibilities. You leave out 4789 or you leave out 5689 and whatever three digits are left out of the 25 cage must total to less than 20 so in neither case can you leave out the 9. This also leaves you with only two possibilities for the 25 cage and since one of those contains a 5 you know that one is impossible.
I didn't cry ... at least, not physically ... but this puzzle took me over 2 hours combined over a pair of sessions (one of which led to a break due to a faulty assumption). On my final go, I was able to find a purely logical path. At the least, this goes in my snapshot collection of completed puzzles. Words fail me.
There are a couple of knight move tricks early on you can use, for example at around 9 minutes you can pencil a 789 into cell 1 and 7 of box 2, they can never go in cells 2 and 8 or they would rule out that digit from the entire 33 pentomino. Similarly you can rule out a 3 from cell 5 in box 3 because which ever cell in the 36 pair in box 2 is the 3 it sees that cell in box 3 by a knights move. Little bits like that help whittle down the possibles. With regards to the title of the video I nearly cried at 34:30 When you put in the 258 triple into column 7 when 2 of the cells were ruled out from being a 2 by normal sudoku!
Do you have any idea how frustrating it is that you often have brilliant logic I don’t even begin to see, but miss the BLINDINGLY OBVIOUS for so long in the same puzzle?
alright so me before the video: The mans excited and if that title says anything, that won't last long jdskak it was a long one good sir, a very long one OH i thought he was gonna cry because he went really far then realized he made a mistake, but no, it was the beauty of the puzzle after: yes it can it absolutely can
I found this as very challenging, unfortunately I could only reach to those 23 digits in the grid (27:34), I didn't want to surrender but I had to after many hours. Now I see I only needed that deduction at 29:48 to finish the puzzle, so close 😥
Mark and Simon, I just discovered your channel and I wanted to say that nothing better could have happen to me in these trying times.
It's getting me through my second confinement evenings, as it did the first one's :) Feel free to browse the history of the channel, you have 2 puzzles a day for months.
I know right! What a Channel I mean what a Channel! It saved my sanity!
Agreed, only found these during lock-down, never thought much of Sudoku, but it is impressive the way Mark and Simon tackle these, and the people who set them... well, hats off. Genius.
The thing that makes these videos brilliant is not just the logic, but the sheer joy you have at solving these intricate puzzles. There's something just so satisfying about watching that combination of talent and love of the game.
34:16 "Now there's probably loads of things we can see here if we're good at scanning." - Simon, not seeing he can immediately place a 2 in one of the three cells he just highlighted just by using normal sudoku logic
Yep, clearly only scanning for knights moves, haha
Find someone who looks at you the way Simon looks at Phistomefel puzzles.
Wish I could.
I hope you're doing well Simon. It's incredible that you and Mark have kept up the blistering pace of 2 videos a day for so long. Cheers!
Simon: I am so stupid some times.
Me: I prefer your stupid to other people's smart.
Got that right!
I wish my smart was at the level of Simon's stupid, I'm legit stupid sometimes
Death, taxes, and Simon calling puzzles “stunning,” “gorgeous,” “brilliant,” “breathtaking,” “unbelievable,” and “simply astounding”
Outstanding
Most puzzles are awful. Simon just doesn't pick them.
And the truth is Simon picks for us some of the best puzzles around.
*Simon calling Phistomefel puzzles
Now we’re cooking with gas!
No idea what you just did but it was fun to watch you dive slowly into madness.
3am in India.. brilliant puzzle... this is one of those puzzle for which sleep can wait .
Reading the title, and thinking "more than once."
You and me both.
That hits too close to home.
The ghost of Halloween...
As well as being the king of all constructors, Phistomefel is also the king of self-explanatory puzzle titles
Simon: "I'm so stupid like that."
Me, still not 100% getting the logic that made him want to cry: 👁️👄👁️
🤣🤣 Simon says "I'm so stupid" or "I'm sure you've all spotted the next move". He gives himself too little credit and too much to us 😁
The logic is beautiful though so I'm going to give it a bash for you. There are 2 lovely pieces of logic combining.
r4c3 is a 2 in the final solution and one of the 4 red cells.
We don't know it is a 2 yet.
We do know that whatever it is there is a number that matches it in the middle box as all boxes contain all 9 digits.
We also know that it is in the 25 cage, and that this rules it out of 3 of the squares in the middle box that are also in the 25 cage ( The 4, 9 and 7 squares in the finished solution ).
We know it can't be in r6c4 ( 8 in the finished solution ) as this is in the same column.
We know it can't be in r5c5 or r4 c6 ( 6 and 5 in the final solution ) because these are a knights move away.
So we have 3 squares left where it can be in the middle box r5c6 r6c5 r6c6 ( 1, 3 & 2 in the final solution )
We also know that all 3 of these squares are in the 17 cage.
So now we know that this number is in both the 25 cage and the 17 cage.
This process can be repeated for the other 3 red squares forcing 4 numbers to be in both the 17 cage and the 25 cage ( I can run through all this too if you like )
There is now only 1 number left in both the 17 cage and the 25 cage that are not the same as each other.
25 - 17 = 8
So one of these digits is 8 larger than the other one.
1 + 8 = 9
If the smallest digit is larger than 1 then the largest digit has to be 10 or more.
As this can't happen then the smallest digit has to be 1 and the largest digit 9.
So there is a 1 in the 17 cage and a 9 in the 25 cage.
Hope this helped. Hard to know where I'm overexplaining or underexplaining.
"It cannot be 12346.... Therefore, it has to be a 6 or a 8!"
Absolutely GENIUS!
Then again, It took me about an hour to figure stuff he wrote down in the first 15 minutes of the video :(
Being able to spot things like that help us feel slightly less idiotic as he goes through other things so speedily...for me it was waiting for him to notice the effect of the 9s in the 30 cage on the 9s in the 25 cage
watching your logical progression is like listening to a beautiful piece of music.
Simon in every video: This is greatest sudoku EVER
Is that mean every next sudoku is better than the previous one? Great solve as always
He's like the Steve Irwin of Sudoku.
It is amazing how many times in these solves you tell us that you are missing some piece of logic and then you move the mouse and randomly stop the cursor on the digit for which you are missing the logic. :) Your enthusiasm is infectious Simon! Thanks for brightening our days.
Yeah, more than once because of the mouse hover I've questioned if they are just doing that to get more comments. Work the algo, right?!
Simply a joy to watch.
Watching Simon figure out how to get those colored squares was unbelievable.
Maybe Simon I didn't love that puzzle as much as you, but it and watching your joy solving it did make me cry.
I did love the puzzle. A knights move restriction tends to make puzzles easier thus even a Phistomefel puzzle was going to fall quickly.
I know they made their choices for the puzzles and the deadline has passed for the fan selections, but I am sure this puzzle would be in the book if it could be. Then again, there could always be a Volume 2 because of the success of this book.
We're many months away from shipping, surely they won't mind streching the deadline to include this one if they feel it's worth it. It would be in the benefit of everybody.
Phistomefel could get his own book at this pace.
There is so much joy in this video I couldn't help but giggling like a little kid watching it even if I couldn't always follow the train of thought. Truly a joy to watch and an amazing puzzle to boot!
Time for Simon's huge nerd cruch on Phistomefel to show
I love watching Simon solve a Phistomefel puzzle as realizes the genius of his setting
Crush
I can't blame Simon.
It’s actually so cute to watch
Simon: I am just so stupid sometimes
Also Simon: is the exact definition of intelligence
It was nice to watch you put it all together.
One of my all time favorites I think. I am going to save it and do it again
What a awesome sudoku and beautiful solving.
I'm so happy that I found this channel.
I spotted a negative constraint that makes me feel happy, too, since I am a beginner in sudoku: In 32:00 when you placed the 589 triple in box 7, the two cells in row 7 can not be a 59 pair, since that would clash with the 59 pair in box 4 because of the knight's move. So one of the two cells in row 7 has to be an 8.
I felt pretty proud to crack this one. I didn't get the nice logic with the two cages sharing the central box, but after working down the restricted cells adjacent to the cages a bit, I found that the 25 cage had to have 3 low digits and 2 high digits, which ended up cracking open most of the rest of the puzzle (I think it is roughly the same logically, but you start by finding the 6,8 in the center, rather than discovering the 1,9).
"25 is such a middling number."
25: Okay 😔
This is insane. I wouldn’t even have found the first friggin’ pencil mark.
It's midnight. => Noticed a new Phistomefel puzzle on CTC. => Realized it's Sunday and needed to wake up in the morning for work. => Hmm. => Well let's enjoy the puzzle before sleep! I can live with a couple hours less sleep ;)
...
This is a brilliant puzzle! The plus shape interacts nicely with the knight constraint. Took me 1h16 to finish it
Not a particularly rough break-in compared to most Phistomefel puzzles. That was a fun one.
Stunning solve!
Me watching Simon's videos:
*Entire sudoku goes right over my head and baffles me*
Notices one simple trick right at the end
"YoU bUfFoOn!*
Oh, this one would be so good to have in the book, but the deadline for suggestions was yesterday... Great video, unfortunate timing.
As I said in my comment, there could be, based on the book's success, a Volume 2.
"I'm so stupid sometimes" - (nods slowly after not having gotten past the 5 in box 2)
The only possible suggestion I could have for this puzzle is a better name. I thought 'knights and crosses' could be a fun one
Please do a one off podcast call with phistomefel, you and Mark. It would be such an enjoyable watch
A really amazing puzzle. I think it becomes much easier if you notice that each cell that is orthogonally ajacent to a +cage sees all the outer squares (and therefore the whole cage if it sees the central one as well).
I was grinning like an idiot the full first half of the solve, what genius constructing
The puzzle and the solve are both completely adorable.
The rare occasion when I've done a Phistomefel puzzle before you! I spotted the constraint of R3C4 on box 5, but I used it to rule digits out of R3C4 rather than into the box 5 cages, and my solve path was much longer. This is a far more elegant solution that allows me to see what the puzzle was meant to be. Thanks for covering it.
If I said that the man's a bloody genius, I wouldn't be telling anybody anything they didn't already know. But I'm going to say it anyway. The man's a bloody genius. That interaction between the cages and the knight's move to give you a difference of 8 in the non-shared digit, well, I agree with everything Simon said about it. Of course, I didn't spot it quite as quickly as Simon did. Puzzle took me hours but I stuck with it, and given that it's a Phistomefel puzzle managing to solve it at all isn't anything to be ashamed of. Absolutely worth it.
It was a brilliant puzzle. It was almost like he created it to play against your very few weaknesses. In this puzzle, you had to do a lot of pencil mark maintenance. If you are not careful it could have easily gotten confusing. Finding the break-in is your specialty who would even think of looking for that.
I think my favorite was the single very long diagonal thermometer over a central magic square. There was just so much symmetry in that one.
I've been waiting for so long to share this conjecture of mine, and now that I have a possible counterexample, here it is:
My conjecture relates to the ability to split an n-tuple of sudoku pencil-marks into a smaller x-tuple and an (n-x)-tuple. It states that any n-tuple which does not have a way to be split it into any smaller x-tuple (there is no subset of the n-tuple with exactly x cells that contains exactly the same x digits in only the cells in that subset) must have a cyclic connection between its cells (for example, having a triple with cells {(1,2,6),(1,2),(2,6)}, numbered 1-3 in order written, we have a cyclic connection of cells 2->3->1 that goes[(1,2),(2,6),(6,1)]. The general pattern, with arbitrarily many cells, is an order such that an ordered pair of any two digits in the cell occurs so that the first in the pair is the second in the previous, while the second in the pair is the first in the next. The cell itself must have both pencil marks possible, and the last cell is followed by the first, as this is an ordered cycle) .
As for the possible counterexample, look at the quadruple in column 6 in 27:23 on screen. It goes {(1,2,4,7),(1,2),(2,7),(2,4)}. I could neither find a smaller split in the quadruple nor a cyclic connection, so it seems to be a counterexample to my conjecture.
An interesting question remains: Can this happen in a solvable classic? If not, what variants allow such a counterexample?
I got to the position at @5:50 and knew I wasn't going to crack it myself so had to watch. What a crazy puzzle.
In my opinion Phistomefel is the best setter I’ve ever seen, the resolutions are always so elegant !! But hard too, I believe I’ve never been able to finish a single of his puzzles without help (the reason why I like to call him Fistomefel... hum)
Me - "Simon!! Why can't you see the threeee's?!"
Simon - "Let me explain this other piece of beautiful logic you didn't see while you were shouting."
Me (still shouting) - "Simon, you're a genius!!"
That was a really cool puzzle. I saw what looked like the break in as soon as it came up on screen and started working on it but had to go get dinner so it sat open for hours before I got back to finish it so no clue on my time but I imagine at least a couple of hours. Felt this one was easily understood.
Phistomefel is en route to drive Simon insane one day.
It’s always entertaining to see Simon’s admiration and subsequent unraveling of Phistomefel’s genius Sudoku settings.
Highly enjoyable cat and mouse game. :))
well solved. Brilliant to see how the knights move interacted with the killer cages to restrict the orthogonal extremities outside the cages.
Missing the devil on the thumbnail! If I knew it was a Phistomofel puzzle I would have watched it even faster
17:19 "this is nuts" never heard him saying sth like this - that was damn funny
Brilliant puzzle and a very happy Simon
"I hope you enjoyed it a shadow as much as I did". In fact I "enjoyed" it FOUR times as much as you did, at least. Somewhere between 2 and 3 hours solving time for me, or 12 hours elapsed if you count sleeping. Didn't spot the quintuple in row 2 right from the start but managed to get the quintuples in the crosses by trial and error. Also did a lot of cancelling digits by knights move only (using colouring extensively). I took a screenshot and went to bed last night and came to finish it this morning. It was only 12 more minutes from the point I parked it overnight to finishing. Maybe I wish I'd stayed up a little more. On the other hand, fresh mind after a good sleep means it might have taken way more than 12 more minutes last night so it was probably the right thing to do! Super puzzle.
Me: **sees title**
Me: Oh, yes. Many times.
That was a tough one. I love Phistomefel's puzzles.
Stared at this for a minute and a half, pencil-marked the 12346 in box 1, then figured ctc would probably cover it next week. Did not disappoint
I actually got the 5
That was quite a deduction in the central box around 10:40, and so quick. I could have studied this for weeks and not come close to seeing it.
I haven't had the courage to try ANY of Phistomefel's puzzles ... all of them are 'way above my pay grade'
I wish I enjoyed anything as much as Simon enjoys sudoku, and I’m a generally happy guy who enjoys a lot of things.
Finally early for a cracking the cryptic video! Hoping it’s a good one!
Simon: I am so stupid some times.
Me: … (mumbling) still trying to follow the logic in box 5
I never got to the 12:40 reveal, and I don't think I would have found it without peeking at the video. The geometry of this puzzle with knights moves is gorgeous.
The entangled shapes make me think about the miracle sudoku 2's thermos.
Great puzzle combining my favourite variants! Once you get over "how on earth is this supposed to work" it's really fun.
Wow! That was truly beautiful. It was too late for the kickstarter nominations, can this be a late entry?
Yes. In fact, trying to solve most of them make me cry.
Actually proud I found the logic that made Simon want to cry, even if I did in a way more convoluted less pretty way.
I played along until that business in box 5. Then I just got some popcorn to watch the rest.
at 34:37 i felt so smart cause i saw the restrictions with the 258 triplet. i only just started playing more difficult sudokus and it takes me multiple attempts with mistakes highlighted to finish them.
Loved the solve and the puzzle :)
"You will never see another puzzle this beautiful," promises Simon for--what?--the twelfth time this month? XD So blessed to have such an amazing roster of setters that each puzzle is a mind-blower.
31:57, "Not used to things I can actually do."
the entire audience whenever we watch him solve a killer sudoku with a knight's move and no givens and requires a sacrifice to Satan: "We know how you feel."
Bobbins! It is sooo *frustrating* when you feel like you get into the puzzle and make progress, even put in one or two digits, thinking you understood the "trick" of it - and then get completely bogged down. Had to give up after having 3 digits and a whole lot of pencil marks in the grid.. :/
I suspect the confusion with respect to R4C2 was because the cell directly above it had 1-2-3-4, so while you're obviously scanning and seeing the 6 you're focusing on the 1234 and.
35:36 - Finally, he heard our shouting at the screen! Well done!
Crazy. Just plain insane...
This puzzle must be in the book!!
Sounds like a perfect sudoku to start at 1am
I suspect that, if they do at all, sudokus reduce some of us to tears for different reasons than they do Simon. Great puzzle btw.
You can get that central logic (that 4 digits are shared among 25 and 17 cage) in a different way.
In the central box you have 3 cells that see all cells of both cages (in total 10 cells). This means that some digits in those cages have to shared, otherwise you wouldn't have any digit to put into those 3 cells. What's more in those cages you can use at most 6 (= 9-3) digits, because you need to have 3 digits left for those 3 cells in the center. So you have 10 cells that use at least 6 digit and each digit can used at most 2 times (once per each cage). The only way you can achieve this is by sharing (at least) 4 digits. So you have 4 digits that are used twice and 2 once (or 5 digits twice, but this is impossible, because cages have different sums).
I also was trying to use this kind of logic for the plus cages, because a cell between two pluses also sees all 10 cells. In such case you get that cages share at least 2 digits.
I don't know why this one was so rough on me, but I know the mistake I made over and over. I kept at various points removing a possibility by what I was thinking was a knights move, but was actually doing a long-knights more (2 forward 1 diagonal). I have no idea why my brain kept doing this but after 4 restarts and 3 hours I finally got the correct solution. Just had to take it a lot slower on the final run. The logic was nice. Also amazing spot on that quad. I didn't see it. I ended up realizing that between the 17 cage and the 45 cell above it that the other non-cage cells in the central box couldn't be 1-3, 4, or 5, leaving 6-9. Then I looked at the possibilities for the 25 cage and realized that 2 of them used three of the 6-9 digits and therefore could not be used because that would force those two squares to be the same value. The remaining two possibilities allowed me to rule the 4 out of the 4-5 cell above the 17 cage which restricted the 17 cage which then restricted the 25 cage which then restricted the 30 cage after getting the 8 in the cell above it. I also played the 79 cell a bit earlier. One thing I did that was a little more convoluted was I looked at where 1s could go and quickly ruled out possibilities such that box 1 and box 4 had their 1s locked. That forced a 1 into box 7 column 3, which eliminated the possibilities further for box 8 down to two cells, box 2 down to 2 cells, and the 17 cage already had them limited in box 5. Then I locked them down to three possibilities in box 9 and a few (I forget how many) in box 6. Box 3 was already limited to the 8 cage as well. I forget what I did next, but one of the digits I was able to place next allowed me to completely unwind all the 1s, then the 6s and got me moving again. I think it had to do with the 17 cage, but after restarting 4 times my mind's a little fuzzy. Still an amazing puzzle. I did try his theorem a time or two, but the times I looked at it, it didn't provide any insight I didn't already have. I want a puzzle where his theorem is critical to solving the puzzle. One where no other technique (other than long chains, which you can't ever completely avoid, basically bifurcation at that point) will work. Can you give us one where your theorem is required? Please do! :)
15:06 "It can be 1,2,3,4,6, it can't be 5, and it can't be 9. So it's a 6 or an 8." Right :D
*7, 9
@@whythosenames You nitpicked the nitpicker! Truly, you are nitpickier than me. :D
this was a pretty nice puzzle. I wrote down all the combinations for 30 and 25 and couldn't get a unique 5sequence in each box, so the trick with the 2 cells out and in was what pushed it thought. I wasn't good enough to get it
Did not have ‘puzzle makes Simon cry’ on my bingo card
At the 11:30 mark the way that I figured that out was I noticed that all three of the cells that were not in cages in the central box saw every single cell of both cages and therefore must contain digits that could be left out of both cages. The 17 cage only has two possibilities. You leave out 4789 or you leave out 5689 and whatever three digits are left out of the 25 cage must total to less than 20 so in neither case can you leave out the 9. This also leaves you with only two possibilities for the 25 cage and since one of those contains a 5 you know that one is impossible.
nearly 2 hours, but a complete JOY!
I am almost done with all of the puzzles in the Killer S. app--except every SINGLE one created by Phistomefel.
Well I hope I won't cry, but I will certainly try 😁
I didn't cry ... at least, not physically ... but this puzzle took me over 2 hours combined over a pair of sessions (one of which led to a break due to a faulty assumption). On my final go, I was able to find a purely logical path. At the least, this goes in my snapshot collection of completed puzzles.
Words fail me.
I am amazed at Simons speed. Took me almost 1:25 hours.
There are a couple of knight move tricks early on you can use, for example at around 9 minutes you can pencil a 789 into cell 1 and 7 of box 2, they can never go in cells 2 and 8 or they would rule out that digit from the entire 33 pentomino. Similarly you can rule out a 3 from cell 5 in box 3 because which ever cell in the 36 pair in box 2 is the 3 it sees that cell in box 3 by a knights move. Little bits like that help whittle down the possibles. With regards to the title of the video I nearly cried at 34:30 When you put in the 258 triple into column 7 when 2 of the cells were ruled out from being a 2 by normal sudoku!
Do you have any idea how frustrating it is that you often have brilliant logic I don’t even begin to see, but miss the BLINDINGLY OBVIOUS for so long in the same puzzle?
alright so me before the video:
The mans excited and if that title says anything, that won't last long jdskak
it was a long one good sir, a very long one
OH i thought he was gonna cry because he went really far then realized he made a mistake, but no, it was the beauty of the puzzle
after:
yes it can it absolutely can
Got the "tear breaking" logic after playing the video twice, but would never ever have figured it out myself .....
I love the symmetry of how both the first and last cells to be marked are "5"s
better title: can a sudoku not make you cry?
how do you get to know the restrictions of the cages at the very beginning?
I made a good try at it, and figured several bits, but botched my logic somewhere and broke it. Ah well, I'll just watch the beauty of Simon's solve.
Am I the only one screaming about the 5-9 pair in box 4 making a 9 in r5c4 impossible - thus completing all of the 7-9 pairs spread around the board?
I found this as very challenging, unfortunately I could only reach to those 23 digits in the grid (27:34), I didn't want to surrender but I had to after many hours.
Now I see I only needed that deduction at 29:48 to finish the puzzle, so close 😥