The Masterpiece

[@nathanweston9681]

"Try it at the link below" Hahahahahaha nope

[@AvatarBowler]

Same. I’d rather enjoy Simon dissecting it than blow my brains to smithereens. Five minutes in and I’m already like, “How do you solve this damn thing? 🤨” 🤣

[@CMF412]

I'm glad he says something, because I hadn't known that was an option.

[@Coldheart322]

Video is 1 hour 37... so for mortals 1 year 37 days to solve this one :-p

[@ZielAmerak]

I only try to solve Sudokus with low 20 min videos, if Simon take more than that, I could be there for days,

[@RealCheeseOnly]

Yup. I started it as he did and 5 mins in I wa like, nope. I do not have the math skill nor the sodoku experience/knowledge for this one.

[@Frans_W31]

Simon: "5 people have solved it, do have a go yourself in the link below" Me: "No, I don't think I will"

[@puritan7473]

... and now having watched the video .. so very glad I didn't click that link!!!

[@ihaetschool3361]

777 likes

[@sirgeremiah]

Well, I had a go. I managed to find 4 different ways to prove things that weren't conclusive. I spent a lot of time doing math and running permutations, then Simon did the math in his head and used his magic brain to skip needing the permutations I did. And I still needed his help to finish.

[@kylemarschner8725]

I've always loved sudoku but always end up getting a headache doing them myself. Watching you i get to follow along with your logic and explenations and everything just seems to make sense without the headache ever setting in. Thanks for that.

[@warren_r]

37 minutes in and still with an empty grid, Simon declares that "We always try to be new user friendly!"

[@valerieprice1393]

Makes sense I've learned the secret like 10 times this week alone

[@thegeminidk]

@@valerieprice1393 if you turn in your punchcard, you get the next one for free

[@J.P.__]

Well, to be fair, I never heard how it works before and it was wonderfully explained!

[@robert-skibelo]

I think the real problem is that Simon is not so good at explaining anything succinctly. I personally find his laborious explanations involving Scrabble tiles rather wearying. I think he may be trying to attract a very young audience. But if so he risks alienating more expert viewers.

[@thegeminidk]

@@robert-skibelo that L in your last name is definitely correct. L + ratio

[@Jablicek]

5 of us attacked this puzzle as a group effort. It took us 66 minutes before one of us did the diabolical logic involved in working out where the 9s go. Staggering that you, working alone, got it so fast! As always, in awe of your ability, Simon.

[@SpeedyBozar]

This is kind of unbelievable to me. After getting to know that not every ring has to contain a 9, it took me like 3 mins to know where the 9s go in gray ring and like 5 mins to know where they go in blue ring. And I am not a sudoku expert at all, I almost never get faster times than Simon or Mark in these videos. So how could it possible take you 66 minutes to figure out something that looks relatively so simple? What specifically is there that makes it difficult? I don't see it.

[@Jablicek]

@@SpeedyBozar We got to 36 and realised that couldn't possibly be right so we got to 29, but then the placement took us ages too. I think that although the group solves are terrific fun, they actually slow us down (in some respects) because, like Simon and Mark, we have to take the idea that's just occurred and explain it to the group. On the other hand, the group has strengths - all of us are weak in different areas so together we've got just about everything covered. Once I realised we've got symmetrical cages, and that numbers must repeat to hit 29, it then allowed others to take it from there - because everyone needs to have input in order for group solves to be *fun*, and it's important to be the one to explain to the others how this thing must work and then step back to let others be useful, otherwise they're watching one person solve a puzzl (and that person generally is not me).

[@SpeedyBozar]

​@@Jablicek I see. Then the previous comment I suppose is exaggeration. Now I think the reason why your group and Simon were relatively slow with figuring out the 9s is that you were trying to establish generally applicable logical reasoning in the solving path instead of just looking at the specific case which had only one clear option on every step. I personally don't know any sudoku shortcuts, I don't remember any solving paths or have any solving patterns. Which usually makes me slower but in this case it helped me to be faster.

[@Jablicek]

@@SpeedyBozar Wow, you found your exception! Glory in it :) Yes, we come up with hypotheses and then have to justify/prove it to the rest of the group, and then we collectively say something like "Oh yeah, that must be it! And now we can do x, y and z.

[@SpeedyBozar]

​@@Jablicek I think it is the opposite of exception. I think it is the absolute normality. I love to play and without having anything memorized every puzzle is a completely new adventure to be fully experienced. Not sure if it is found or not lost, probably a point of view.

[@iabervon]

At 25:50, I got into an argument with Simon: Simon: "If it's got 3 9s in it, then the perimeter would sum to..." Me: "135." (since (36+9)*3=45*3=135) Simon: "27 and 3 lots of 36, which is 118, plus 27, which is one th... 145, isn't it?" Me: "No." Simon: "It's 145." Me: "No." Simon: "Yeah." Me: "No." Simon: "Yeah." Me: "No." Simon: "I'm going a bit crazy, but yeah, I think it's 145." Usually when I shout at the screen, the person doesn't respond. Occasionally, the person notices what I said, which is fun. But I've never had someone argue with me before.

[@Anne_Mahoney]

The thing is, 3 lots of 36 is 108. But, whatever, you got there in the end.

[@marshm3llow467]

Also 144/4=36, since it's [(12)(12)]/4 = 3 (12) but doesn't matter in the end, I guess, since I would never have solved this puzzle myself.

[@series161]

haha anyone else reading this like a script? 😂

[@Mr_Top_Hat_Jones]

I was about to post an unnervingly similar comment. I’m glad I checked first. I’m also glad that I wasn’t the only person arguing with my screen. Simon was so sure of himself that, for a second, I thought I was the one going crazy. 😂

[@consciousness147]

HAHAHAHHA that's so funny! 😂😂

[@SmartHobbies]

Testers: “brutal, couldn’t solve it, gave up” Simon: “Let’s give it a go!” Such dedication.

[@ocaly]

yep. the sad truth that all it takes is dedication

[@J3009]

@@ocaly And a lot of time

[@Ulkomaalainen]

@@J3009 And some knowledge. And quick thinking still.

[@Rubrickety]

Let me just take a moment to note how completely bonkers it is that CtC posts a minimum of two videos, recorded the same day, 365 DAYS A YEAR. They solve and post while on vacation! They solve and post during Christmas holidays! If they fail on a given puzzle on a given day, they do another one! It is, frankly, flabbergasting. If I accomplish one important thing in a week I consider it a productive week.

[@eclectichoosier5474]

That's why I watch every video. I love watching masters at work, and I love watching people who love what they do. And it's much better than social media and being bombarded with politics and bad news from every direction. The world could use some more Simons and Marks.

[@BanaiFeldstein]

They have sometimes pre-recorded during their vacations, but yeah, it's still a ton of videos, and it is slightly more than one per day on average (each), accounting for a few puzzles they didn't finish and had to do another for the day.

[@emilywilliams3237]

Well said.

[@solfeinberg437]

Define important, please.

[@esmin2400]

@@solfeinberg437 brain training is important, as is education

[@salamicam12]

26:32 “I’ve done it… when I say I’ve done it, I’ve done the most minor thing, but I have done something.” Incredibly relatable but also kinda inspiring! On those days when you have little motivation or energy, even a little thing you do is still something.

[@Angi_Mathochist]

I had that feeling a lot with this puzzle. "I've figured out so much! ... I still don't have any actual numbers in the puzzle, though."

[@paulwright13]

So impressed with Simon's ability to keep talking, be engaging and humorous, whilst being bereft of ideas, I love the logic path, it took me 4 hours, then watched the video to see if id missed an obvious step but no, just not in that league :), would love to see a youtube video from Nahileon on how on earth that was conceived

[@Marronii]

other people watch a 90min football world cup finale, I watch this machine of a man solve a sudoku.

[@andilemakanza1768]

I watch both😂

[@hugodiazroa]

​@@andilemakanza1768 me too, and also god awful matches like chelsea v luton

[@mr_gerber]

10/10 times would choose this again

[@SheilaMertens]

Oh boy... dear Simon, this wasn´t just a solve, it was a journey. And in the end, I too had a tear in my eye, just to see your elation, just... unforgettable. Love, Sheila.

[@piarittersporn]

Even in ten times Simon's time, I could not have solved this complicated puzzle. So I just watched Simon solving it, which was exciting and amazing enough.

[@DekarNL]

Make that 1000

[@solfeinberg437]

I think 10 times the amount of time would be a reasonable (albeit certainly not guaranteed) time for me to solve it. Emphasis on I want at least that much time, not that I'm hopeful I'd be successful. But it's possible. It would depend on having certain insights. Even knowing what to look at. It certainly wouldn't happen without asking the right questions even in 100 times the time it takes Simon.

[@piarittersporn]

@@solfeinberg437 👍🙂

[@erlandodk]

What on Earth are you apologizing for? Noone watching your videos feels them to be a waste of time. We are all here for your amazing solves and this one was truly epic. In my opinion one of the finest solves you've ever done. What a puzzle and what a solve. Bravo! 👏 👏 👏

[@solemnwaltz]

He seems bothered the video is an hour and a half, but I loved it I always get a bit sad when the puzzle is finally solved This was a fun journey!

[@noitallmanaz]

I think it is a British thing... I think he knows we all like these videos...

[@inspiringsand123]

Rules: 02:59 Let's Get Cracking: 06:44 Simon's time: 1h29m17s Puzzle Solved: 1:36:01 What about this video's Top Tier Simarkisms?! Phistomefel: 19x (09:17, 09:30, 19:32, 19:52, 20:08, 30:30, 31:02, 31:59, 32:31, 32:37, 34:07, 35:01, 36:59, 37:15, 37:27, 40:09, 41:22, 41:36, 1:13:48) The Secret: 5x (12:13, 12:16, 12:17, 12:20, 12:22) Three In the Corner: 2x (55:43, 1:01:37) Goodliffing: 1x (1:23:44) Knowledge Bomb: 1x (27:29) You Rotten Thing: 1x (48:50) And how about this video's Simarkisms?! Hang On: 17x (09:22, 09:22, 09:22, 11:46, 13:29, 20:55, 20:56, 31:13, 31:13, 31:13, 31:17, 53:00, 56:46, 56:48, 1:05:53, 1:30:09, 1:30:09) Ah: 15x (13:15, 22:09, 34:44, 34:45, 34:45, 1:04:48, 1:14:33, 1:20:47, 1:21:36, 1:24:01, 1:28:07, 1:29:35, 1:33:56, 1:35:21, 1:37:08) Obviously: 12x (10:50, 22:57, 26:53, 27:02, 31:47, 34:24, 39:45, 56:37, 1:05:20, 1:09:31, 1:16:39, 1:27:25) Sorry: 11x (07:56, 10:35, 54:21, 56:15, 1:24:19, 1:24:27, 1:29:23, 1:29:26, 1:29:26, 1:30:45, 1:36:09) By Sudoku: 6x (35:21, 1:01:52, 1:02:00, 1:24:01, 1:34:08, 1:35:51) Nonsense: 5x (20:24, 20:28, 28:07, 59:18, 1:26:57) Ridiculous: 5x (1:11:58, 1:12:00, 1:21:28, 1:36:31, 1:36:34) Surely: 5x (19:47, 21:43, 30:27, 30:30, 1:35:04) Proof: 5x (19:19, 19:26, 19:32, 37:07, 40:06) In Fact: 5x (03:17, 17:00, 19:47, 36:21, 1:17:30) Good Grief: 4x (03:40, 40:12, 1:10:51, 1:26:28) Lovely: 4x (06:32, 14:44, 1:08:22, 1:33:25) Beautiful: 3x (55:15, 1:09:05, 1:27:34) Brilliant: 3x (01:44, 1:11:52, 1:11:52) Corollary: 3x (31:17, 31:29, 1:16:56) Goodness: 2x (1:10:54, 1:36:12) Naked Single: 2x (1:21:46, 1:21:53) Pencil Mark/mark: 2x (28:06, 1:27:12) Unique: 2x (05:55, 06:13) What on Earth: 1x (32:06) Bother: 1x (1:04:41) Clever: 1x (1:21:21) Missing Something: 1x (1:13:13) Stuck: 1x (19:16) Incredible: 1x (05:52) Extraordinary: 1x (02:47) Going Mad: 1x (11:46) Take a Bow: 1x (1:37:16) Unbelievable: 1x (53:24) What Does This Mean?: 1x (41:16) Scrabble Tiles: 1x (38:11) Cake!: 1x (01:46) Most popular number(>9), digit and colour this video: Twenty Nine (36 mentions) Four (145 mentions) Green (21 mentions) Antithesis Battles: High (2) - Low (2) Even (15) - Odd (3) Outside (5) - Inside (0) Row (23) - Column (14) FAQ: Q1: You missed something! A1: That could very well be the case! Human speech can be hard to understand for computers like me! Point out the ones that I missed and maybe I'll learn! Q2: Can you do this for another channel? A2: I've been thinking about that and wrote some code to make that possible. Let me know which channel you think would be a good fit!

[@TheTimurQ]

Bless you, stranger!

[@ChronologicalLogic]

Speech to text recognition with some prefed variables? Nice.

[@suzil7687]

Wow. Just wow.

[@bricy6437]

This bot just tickles me! So funny!

[@paulc2335]

But... the cake is a lie!

[@linforcer]

I love how Simon basically finds the most roundabout way to prove that 45 - 9 = 36 and it was extra amusing because I could see it coming a way away.

[@drc500free]

If you take your birthdate, add 6, multiply by 2, add 7, subtract 7, divide by 2, subtract 6.... you get your birthdate!

[@leickrobinson5186]

Exactly! Let’s take 45 times 8, subtract 9 times 8. Hmm, “is that even divisible by 8?” 😄

[@ymiros0953]

And he goes on like that whenever he does calculations with something in the corners, making lots of errors on the way lol. At least none of them were fatal.

[@realGBx64]

@@leickrobinson5186 definitely would have been easier (and easier to follow) if he wrote these things down for the mathematically disadvantaged like me

[@geminimaxxim]

There's something so incomparably wholesome about Simon wanting to make the video simply to save the logic in the first half hour.

[@Leap_of_Wraith---Stephen]

I know I'm going to sound like Simon here, but THIS PUZZLE is legitimately so *brilliant*, that it leaves me almost speechless. I honestly think this is better than (at least most of) Phistomophel's puzzles. Such a deviously difficult break-in, step after step, with each minor deduction there were a hundred more to make! But Nahileon held your hand through the whole ordeal and gave you just a glimpse of their brilliance. What a journey to be privileged enough to even watch this be solved. Thank you Simon and thank you Nahileon.

[@aleksandartasevski1576]

Q: Do you have any special powers? A: I can proof the Phistomefel Ring for you. I just loved Simon's emotion at the end. So touching. I'll never stop following this channel.

[@compdude551]

Such a beautiful explanation. I understood it completely. I should say I don’t play sodoku everyday. Making his explanation that much more impressive.

[@ingvarsuigin609]

Yeah, there are puzzles wherre I look at the design and think - someone tried to draw Phistomefel's ring on it, I wonder if that's a hint.

[@johnpauladamovsky86]

Does anybody else out there really, really, really feel like they want to reach through their screen to hand Simon a calculator and a sheet of paper?

[@robert-skibelo]

Yes! He wastes a lot of his time and ours by insisting on trying to do everything in his head. Which is odd, because he also worries about the videos being too long. Plenty of people in these comments have suggested that he use a notepad or that the app should incorporate a scratch pad. But viewer suggestions are apparently not read.

[@MrXantrias]

@@robert-skibelo if it was suggested and seen then they must have considered it and decided against it. if i don't have 1.5 hours to spend on watching a video, i don't watch it. if I DO have the time and decide to watch it, I don't complain afterwards about it.

[@haleywink1307]

So often! it's a wonder he remembers any of the stuff he says, I'm always thinking please write this down for reference 😂

[@KingOfShadeEmpire]

@@MrXantrias Now I too took a look at the video's time and made sure I had time to watch the video. The problem is, I came here for the logic puzzle, not elementary school maths talked out loud. So it's a matter of expected content, not video length.

[@Cashman9111]

@@MrXantrias oh, I do have the time, it's just... stupid. it's ofc their decision, but I really fail to see what they (or we) gain by this

[@th.nd.r]

Brilliant setting and solving. I see a lot of people in the comments complaining about overcomplicating a step, but this is such a complex puzzle that I would argue any solution whatsoever is ridiculously impressive and an accomplishment that I would never attempt. Well done. A great discovery by Nahileon as well.

[@richardgower2605]

Simon: "Do Give it A Go" Me: "I think I'll Sit this one out" 95 Minutes Later: Me: "Excellent Decision".

[@martinottesen1053]

this was me as well

[@theashen]

Absolutely mad. What a solve. Simon, you're amazing. Seeing you solve these is an absolute highlight of my days.

[@bobogaulout]

Never a waste of time to watch genius at work. Amazing work

[@grimsqueaker5333]

The impatient people can watch at 1.25x or 1.5x speed, the rest of us get popcorn and happiness seeing the video length.

[@jasonroos8431]

This puzzle lives up to the video’s title-truly an amazing puzzle and an absolutely gripping solve!

[@alainculos9294]

I can only support this statement. Both the puzzle and the solve are stunningly beautiful & mind-blowing. Personally I gave up once I had "found" that the gap between 9's was 36 :-) ... I was some way from reaching the next level of thinking required to solve this puzzle!

[@reidakted4416]

Usually Simon's videos are a nice, relaxing journey through beautiful logical deductions that I follow along and nod, but this one reminded me of walking in on a graduate quantum field theory lecture. 🤣

[@WinterRaven-si9yc]

I mean this in *literally* the nicest way possible: after just under n hour of math babble, we have more math babble, an empty grid, and Simon saying he's got the solution. I love these videos, they're so entertaining to watch cause I'm sitting here trying to figure out how any of this works and he's just chugging and plugging away with a helluva lot of patience. I commend you sir for not getting bored or frustrated halfway through this.

[@KCatch22]

When Simon said that one of the rings must have no 9's I was convinced he was mistaken because the rules clearly state that the logic of the rings is dependent on the 9's. It even included extra clarification of the logic if one of the rings has a single 9, which would only be possible if there were 9's on all rings. Such a red herring!

[@solfeinberg437]

Yeah, I came up with 36 between the 9's (implicitly assuming every ring had a 9) and was done with that question. The damn puzzle clarifies that if there's one 9 on a ring - it counts as both ends of the range. It would've helped if they also discussed the zero 9's on a ring case.

[@N9199]

I did the following logic unknowingly assuming that there was at least one 9 per ring: You can always group a sum between 9s with one of the 9s, also, there are exactly 8 9s in the rings, using that we have that 8*(s+9)=8*45, which can be solved as s=36. Armed with this I thought about the outer ring, the total sum of the outer ring must be k*(s+9) (k is the number of 9s) and also 4*45-a (a is the sum of the four corners), so k*45=4*45-a or equivalently a=45*(4-k), now we know that 0

[@CF0RD]

It completely deceived me. I never would have thought that a ring contained zero nines 😅

[@subaction]

The wording of the rules is awful. It contains an outright error. "In the rings, the sum between 9s must always be the same throughout the puzzle." It is specifically worded "must always be the same throughout the puzzle." That is a direct, unambiguous statement that there is one, single sum, common to all the rings in the puzzle. Outer ring has sums of 25 between the nines? The other two rings must also have sums of 25 between the nines. One value "throughout the puzzle". That would naturally force larger rings to contain more nines. In fact, each ring has its own, different sum from other rings, directly contrary to the rules.

[@CF0RD]

@@subaction I agree and would have thought so too

[@Quintinohthree]

37:20 a simpler proof: There are no more than four instances of any digit in any of the rings as they span only two rows and two columns each. The minimum number of digits less than 9 required to make 28 is four (8+7+6+5), therefore the gaps in the inner ring with four 9's need to be at least four cells. Adding the 9's the strings need to be at least 5 cells, and there need to be four of them, so there needs to be at least 4x5=20 cells in such a ring. The innermost ring is only 16 cells, so it cannot have four 9's.

[@christophstahl8169]

The break in is insane. Looks utterly impossible. Of course I didn't expect an outer ring with no 9s and added the needed 9s with the 36... realised that's not it and then it flowed well. And just when I thought I had it in the bag I got to the thermo and that nearly broke me. I made so many mistakes there and had to rewind a ton... Mental (=fantastic) puzzle. So well crafted, I am in awe.

[@Kellfiree]

As an adult with only basic Sudoku experience, and as a new viewer, watching you solve puzzles and explain the logic as you go is so fascinating. I know just by watching you that you love doing this, which makes the experience so.... Comforting. It makes me happy. Thanks Simon. 🙏💖👍

[@davidhughes7174]

Magnificent. Your perseverance is incredible Simon. Thank you Nahileon for helping produce one of the great wonders of the internet.

[@jessochberg4034]

Simon you are PURE therapy! What an absolute joy it is to journey alongside you whilst you solve these puzzles! Sincere thanks to you.

[@josephstrauss1145]

It took me 2 weeks of staring at the screen day in and day out, but I finally solved it. This is just incredible. Nahileon, you are some kind of sudoku god

[@Angi_Mathochist]

Took the puzzle, stopped the video, solved it over several days, came back. 1st step: Must be no 9's in yellow ring: check. 2nd step: Sum between 9's must be 29: check. I'm pretty sure we did the exact same math, but you somehow did it in a fraction of the time and without writing anything down. By this point I also had that the corners had to be either 8875 or 8776. 1:24:44: mine looked exactly like yours at this point. Except for the 3 middle orange cells on the left, which should not have 6's in them (the 6 has to be up above). My solution ultimately involved a lot of math and long lists of possibilities for various bits, and then logically eliminating possibilities. You somehow do all of that in shorthand in your head. I have more of a disadvantage these days because my disability means chronic fatigue + brain fog + pain + pain meds which add to the drowsiness... But still. I was never quick. Good at getting there, in the end, but never terribly quick. :) You are good AND quick.

[@isavedtheuniverse]

Can you imagine getting the yellow box filled in, right when you said "please don't be any more hard steps" Simon, and then seeing there is a swordfish on 6's or something like that and then seeing that it goes into some triple nested swordfish nonsense. 96 minutes of madness indeed. The relief and jubilation in your voice at solving it was just wonderful to behold. Absolutely amazed.

[@MarkTillotson]

An (unusual for Simon) arithmetic slip up at 25:56 - If you learned the 12-times table, you'd know 118 doesn't appear in it. 36 x 3 = 9 x 4 x 3 = 9 x 12 = 108. 118 only has 2 and 59 as factors. From this I deduce Simon's schooling was post decimalization and he only learnt the 10-times table. pure logic! This is quite an epic solve, glad this error didn't happen to lead you astray at that point!

[@JuanjoTriolo.11]

"I'm so sorry to waste your time like this"... If you just knew that watching your videos is the best part of our days...

[@danthemaninapan]

Proud of myself for solving this one! And so happy I made the decision to give it a go. It's late now, but looking forward to watching Simon discover it tomorrow :D

[@AquaMusica305]

I love learning the phistomefel ring theorem from you and it was worth watching the whole video. When you figured out the numbers 3-4-2 in the inner blue ring corners getting help from the 3 on the left it made me realize how cool the puzzle little hints were effective still to solve it. I have to rewatch this tbh to dissect your logic with the 9’s in the red boxes how they weren’t green.

[@steve38288]

Amazing puzzle and solve. Ironic that the big breakthrough at 26:30 contained a math error. "Three lots of 36, plus 3x9..." does not equal 145. Three lots of 36 = 108, not 118. Plus 27 equals 135. The logic that followed still works because the minimum of the outer ring is 146, which is more than both 135 and 145. Not a criticism...I couldn't even get that far. the logic to get to the math error was impressive, and I'm sure you would have caught it if it had mattered.

[@banjoskeleton8399]

Good to see someone else noticing this. I was thinking it might mess him up at first, but the fact that it still works is pretty lucky. Getting that far was about as much as I could do, and it's honestly impressive that he manages to solve it at all!

[@kielblanton]

Incredibly lucky that 145 is still less than the threshold. Simon desperately needs to put a calculator on the screen and run his equations through it.

[@crystalgehrt8861]

I was thrilled when I was able to solve this. Actually, I was thrilled when I solved each step! That said, I was able to type in a bunch of numbers in the grid (my equivalent of scratch paper) to add up and average each ring until I came to the number. I have no idea how Simon can hold all those numbers in his head WHILE doing arithmetic. On the thermo at the end, once I got 4 into two places, I looked what would happen from each of them in each direction, and kept running into 128 triples which clashed with a 128 nearby. That seemed easier than scanning the columns looking for clues. I think most of my other differences were mentioned in comments. Simon, you and I both deserve a giant piece of chocolate cake after this one! And maybe you should get two, since without you, I wouldn't have ever learned to solve well enough to tackle this puzzle.

[@els236]

I haven't done Sudoku in a long time and I can barely complete "easy" ones, but man, after YT randomly recommending this channel, I've watched about 3 hours (3 videos lol) and it's insane how mind bending and intricate these puzzles are.

[@ronjohnson6916]

Please think of this one next time you feel moved to doubt how clever you are. A solve to be truly proud of. And of course, take a bow Nahileon.

[@NighT-WolF85]

This is absolutely crazy and words are not enough to describe this puzzle. Congratulations for solving it. This video should get a million views because there is no greater madness to be found anywhere else.

[@SpeedyBozar]

This is exactly the kind of puzzle that fits me. After understanding the rules everything became so smooth and beautiful. Thank you very much for featuring this amazing puzzle. And thanks to Nahileon for putting up the work and setting up the puzzle.

[@stevieinselby]

I love the complicated way Simon works out 8 × (1+2+3+4+5+6+7+8) ÷ 8 😆

[@orosma868]

Yes, I loved how pleased he was that he arrived at 36! ;)

[@suncat530]

@@orosma868 36 factorial is quite a big number ahah

[@valadonis]

I hope this isn't too off topic... I just want to say that Simon is a joy to watch... he has a beautiful mind, is quite articulate, and not at all vulgar (at least in these videos). I especially love to see and hear the expressions of astonishment when he figures out a bit of logic, and the praise he gives to the setters. Kudos upon kudos to you, sir.

[@longwaytotipperary]

So much fun to watch along with you and Mark!

[@NeilCrabbe]

I love that at 1:06:40 you work it out by maths, completely ignoring sudoku.

[@benjiboy1337]

That is the single most brutal break-in I've ever seen. Well done cracking it!

[@madeleinearancibia]

That was absolutely mind bending. I had to rewind the video a number of times just to follow what Simon was talking about. Well done!

[@clara931]

What an amazing ability to keep numbers in the head and run some astonishing mental maths!

[@TheAntonymer]

These were the best spent minutes I'll never will get back. I am so impressed with your solve. And I am so happy to get the opportunity to follow along with your train of thoughts. Hats off!

[@jimfrenken1349]

Most beautiful Sudoku I have ever seen. Great solve! I love your tenacity and how well you formulate the steps that you take during your solves.

[@yarati4584]

At 1:33:00, you can rule out 1 from r4c5 and r6c5, because it must be flanked by 2 and 8 on the thermo, thus breaking r4c7/r6c7, respectively. That's a different way to get the 1 in r5c4.

[@JPCruz]

At 1:33:05, an easier way to confirm 1 in C4R5 is to check the horizontal sequences on any other option for 1 in box 5. Both C5R4 and C5R6 would generate a 812 horizontal sequence, leaving no option for C7R4 or C7R6, so 1 in box 5 has to be C4R5. I believe that was the intended path. Of course I would not make it to that point if not following Simon's logic, so after more than 90 minutes of very hard logic some small details could be hard to see. Kudos to your great solve!

[@trygve2716]

I am officially hooked to these long ones! You are so clever and humble at the same time it's flabbergasting 😂

[@Cogskate]

Wow! This was such a fun solve-along, though I had to follow you closely through the initial logic. Big thanks to everyone involved.

[@mikemcculley]

I would love to watch a video chronicling the creation of a puzzle like this. From inspiration to completion.

[@Gonzalo_Garcia_]

77:37 for me. I have to admit I had one glance at the video though, as I had made a mistake and couldn’t find the way to fix it. In the end it was just one digit, but the few seconds in which I thought everything I had done so far was wrong were scary. Awesome break-in, I’m very happy I was able to do that part all by myself.

[@andrewnelson2525]

Took me all day to solve this with several multi-hour breaks. I alternated between making quick progress, making no progress, and breaking the puzzle. It was actually after I knew there were four 9s in the blue and grey rings, and I filled 9 digits in the Phistomefel corners that I stalled the longest. I'm happy I finished this puzzle at all, and very pleased to do it all in the same day (within 12 hours even). So much fun to watch Simon struggle, often finding more complicated alternate paths -- faster than my simpler logic!

[@Rubrickety]

Normally Simon does vastly better than I in solving because he quickly hones in on general truths while I muck about with specific cases. However, in this instance that surely led him astray in the early part of the solve, as he entertained abstract notions like the outer ring containing only two 9s. A few seconds trying that out would have quickly shown that you'd get an absurdly large sum which the remaining 9s packed into the inner rings couldn't possibly accommodate.

[@oldmomj5088]

Love watching CTC! Thank you for your videos!

[@lewsouth1539]

[35:01] The *obvious* way to see that the inner ring doesn't have four 9s in it: The *average* gap between the 9s would be 3, and 3 digits can't sum to 28! (Btw, the common sum would have to be > 28, since there are also 8s in the outer ring. This is also easily shown for any arrangement of four 9s in the outer ring, no theorems needed. (As Simon determines later!)) Also, the given 3 is quite irrelevant.

Of course this is obvious to Simon. But having almost half a million subscribers their is a need for leaving simpler deductions as a part of the entertainment.

[@Spungomage]

Even easier: Between two 9's in the outer ring there would be every digit except one - in row 1 say 1 to 7, with 8 in r1c8. Now the group in column 8 includes an 8 and cannot be the same total as 1-7. Immediate contradiction without even needing to consider the middle ring.

[@Shif80]

Understood almost nothing after more than an hour but eventually managed to follow along. But I just enjoy watching someone who’s brilliant at their craft, do their thing

[@Thurhame]

The first thing I did when solving this puzzle was calculate that each ring segment sums to 36. The second thing I did was prove that the grey ring segments CANNOT all sum to 36. The third thing I did was cry. Once Simon pointed out that not every ring has to contain a 9, I was able to go back to the puzzle and solve it properly. Thank you Simon!

[@Kimakae]

I love when Simon starts clutching his head, that’s when you know you’re about to get your mind blown

[@d4r4butler74]

YAY Simon!!! Congrats on getting the puzzle done for us. Thank you.

[@clapanse]

At 36 minutes, you took an extremely roundabout way to figure out it was impossible. A much simpler approach is: Given that you know there are 4 9s on each ring, the *very best* you can do is spacing them equidistant from each other. Any other spacing results in at least one gap that is either longer or shorter, so regardless of which your goal is, you're shooting for equidistant. Because of phistomefel as you said, the outer 9s are fixed, and since each gap is in a straight line, we know it sums to 28 (as you said). However, we can apply similar logic on the inner ring. Spaced equidistantly, every gap is 3 spaces. If (ignoring all sudoku rules) we placed a 9 in every single square, that still only gets us to 27, so even ignoring every other restriction, it is not possible to achieve gaps of 28 with single digit numbers in that ring with 4 9s in place. Therefore, it cannot be correct. (Genuinely amazed and impressed overall though. I can spot little things like that sometimes, but I guarantee you I couldn't solve this whole puzzle)

[@jaywei4803]

Maybe even simpler: If the inner ring has four 9s, those four 9s’ positions are fixed in the outer ring. But their so-fixed positions are simply impossible, because equal sum between any two 9s would force the four corners of the outer ring to be the same, i.e., 45 minus 9 minus the equal sum.

[@maoman4855]

I was thinking the same thing! Right about 36:00 when he started coloring in the red squares in the corner I literally burst out laughing and said out loud to my monitor "Simon what are you DOING!?" It's such a hilariously overcomplicated simon-esque way to disprove what ought to be a fairly simple and straightforward thing. I actually had to go back and rewatch a bit because I was laughing so hard I couldn't hear him anymore.

[@victoriam6569]

I tried this puzzle thinking every outer circle needs 9s, concluded it was impossible and almost gave up. I should definitely pay more attention to the details of the rules in the future... Thanks for the puzzle and the solving!!!

[@killamoosdraree730]

It took 3 hours and 13 minutes with a few interruptions to solve this thing. It was quite fun. Thanks for continuing to share these unique puzzles with us.

[@davidblake6889]

Simon, thank you for that video. The mental effort involved in solving that puzzle was enormous. I'm glad to say I followed most of the mathematical steps you took towards a solution. But I am sorry to say, I could never have found the solution path for myself. Thanks for making the journey possible for me.

[@jonnies]

I’ve been assessing your work for a while now and I’ve come to the conclusion that you could actually complete this puzzle all by yourself.

[@enoesiw]

this solution was gorgeous! massive kudos to the person who created it and you for solving it so elegantly!

[@wpolly]

Amazing puzzle! Solved in 51:16.

[@felicote]

At 34:00 there's a much easier way of finding a contradiction. Given the arrangement of 9s in the outer ring. Let a be the value at the top left corner and s be the sum between each 9. The first column sums to 45 = s + a +9. The bottom row sums to s + 9 + b = 45, where b is the value of the bottom left corner. This means that a =b a contradiction since they are in the same column.

[@Mrqwerty2109]

Simon and Mark, you two are the most brilliant minds in the UK

[@rosiefay7283]

Simon, that was an amazing solve of an amazing sudoku. After seeing your final reaction, I was similarly awe-struck that the rings could accommodate 9s and that the other digits were so constrained that just 3 givens and that odd thermo were enough to break all symmetry and determine a unique solution.

[@realGBx64]

I was not watching the channel for a year, and I am happy to see on my comaback how far the sudoku app used got with the multi-coloring and stuff. Now the only thing missing is to be able to put in big numbers with green or something so Simon doesn’t ever confuse a digit he actually found with one he wrote in as an example.

[@nep.h]

I finally finished it! It took me two days to figure it out, and I agree, it absolutely was brutal. But it was SO much fun. I had to take quite some notes until I figured out how the logic in this puzzle worked, so now I'll watch your video to learn how to do it faster next time I come across something like this again :)

[@Houseof1001Stories]

at 92 minutes, you discuss why one of the cells can't be 7 by a long explanation, but an easier way to see that can't be a 7 and the cross cell can't be 3 is that it would put an 8-1-2 across the top of the box, which would negate all options for box 6

[@GK-jg2ee]

Brilliant puzzle, took me like 8 hours across 2 attempts to get there and it was fun the whole way 1:32:08 I think what Nahileon might have intended here is that if the top middle or bottom middle cell in the middle box is a 1, then it must be flanked by 2 and 8, which breaks the 128 triple in the orange ring. Hence, the 17 cell has to be 1.

[@disorderedfox]

Or, similarly, the whole logic for figuring the center box layout being something like: - You have two options for 8 placement (top left and bottom left) so 4 possible layouts - going 87654321 either clockwise or counter-clockwise. - Going counter-clockwise from the top one breaks the 128 triple. - Going counter-clockwise from the bottom one breaks the 67 tuple. - Going clockwise from the bottom one conflicts with the 1 below. Hence, it's going 876..1 clockwise from the top left.

[@mariogomez2153]

I can`t belive a watched it from start to finish with the same thrill you had solving it. thumbs up to you Sir.

[@ConsorcioToxico]

Thanks. More exciting than a Marvel movie. I love this one

[@CrackingTheCryptic]

Thanks Fabian - much appreciated :)

[@Swynndla]

WOW ... just WOW. Simon, I love seeing you solving these next to impossible ones that takes you a long time where you really have to plead with your brain to com up with something, and I'd like to see more like these!

[@christopherswanson5849]

I love how complicated he made proving there were no nines on the phistomefel ring 😂 Once he showed that the gap sums in the outer ring were at least 28, that means there are at least four cells between any 9 on the phistomefel ring, but there just aren’t enough for that and the four 9s

[@worriedpikachu174]

or even simpler: with that arrangement of 9s on the outer ring it's impossible to have the same sum between them. you'd have to put the same number in all four corners.

[@yyxdavid8088]

Took me nearly 70 minutes. I think the beauty of the puzzle lies in the inner thermometer, which seems subtle at first glance but of great beauty with proper logic direction.

[@doctorSpitfire]

When Simon is going through to prove that you couldn't have 3 9s in the outer ring with a gap value of 36, there was an easier way for me to visualize why. If you consider that to have 3 9s on the outer ring one of them MUST have one of those in the corner. Then the column it's in adds to 36, so the next 9 would have to be the first square after the corner, and the row is the same, leaving 13 spaces in between those 2 9s. The smallest you could make those 13 squares is 1 through 7 plus 1 through 6 (with 7 in the corner) which sums to 49

[@aquaticIntrovert]

I literally shouted out loud when he started doing Sudoku with that 5 that he had placed as an example, that's just how invested into this I got

[@thumper8684]

I did it! 92:23 Phistomophel's ring really helped. The 2x2 corner squares tell you the totals in each of the three rings. The two outers are equal, the inner ring divides by 8.

[@malvoliosf]

At 1:31:13 Simon misses a trick: when he remove the 6 from r6c6, he can also remove the 7 from r6c5 (since it must be adjacent to some possible value in r6c6) and therefore remove the 8 in r6c4 as well. That would leave r4c4 as the only cell for an 8, and reduce all the other cells in the box to two possibilities, corresponding to a clockwise and a counter-clockwise thermo. I think the puzzle would fall over at that point.

[@not-on-pizza]

Not quite. The 7 removal from r6c5 is correct, but you can still have 8 in r6c4 and descend clockwise from there.

[@mxpxorsist]

@@not-on-pizza that is not possible either because that breaks r6c7 which is 1,2 or 8

[@makestraightthewayministries]

every time I witness you solve the impossible, I can't seem to describe it to others as anything but an absolute miracle of intellect. Well done, Simon. Can't wait for the next!

[@alexandrawalker2469]

people who can just think like this are some of the most brilliant to watch think. you learn through osmosis, honnestly. Well done sir! Well done!

[@robusterbrown1291]

This was insane. I’m so impressed at all the tools you used here.

[@solemnwaltz]

I've never seen a person so thrilled to have digits in the grid. Beautiful

[@animaaad]

I am just stunned by how smart both Simon and puzzle are. That's amazing

[@chessburns]

This puzzle is AMAZING! How the constructor came up with the idea i will never know but gr8 solve by Simon. It was an absolute sublime genius solve. I loved his reaction at the end wen he said he was gonna have a quiet cry. I believe him. I dont blame him. Thank you Simon for your beautiful solve.

[@magnumpolmatier8184]

Awesome video. Thank you for pushing on!

[@ezzie.g]

Fantastic and fun. A couple differences in logic, but one I haven't seen mentioned which I thought was a key at 93 minutes in was that the 1/7 in R5C4 could not be a 7 - because either way around the cell would eliminate a 128 set in Box 6.

[@emisor9272]

Was just around that part of the video when i read this, beautiful

[@illilillilifernhaven5277]

1:37:42: You can't have 4 9's on the outer ring in those positions, because two of the grey segments are missing one different number.

[@dustpan5356]

I’m relatively new to the channel so just now watching this video. Haven’t seen this elsewhere in the comments and maybe no one cares at this point, but… Towards the end, the logic to solve the thermo in box 5 is to look at the 128 triple in box 6. This prevents a 3 from being in r5c6 because a 3 there would cause a 128 sequence in either row 4 or 6 of the the thermo.