Is This The Hardest Sudoku We've Ever Attempted?

[@matthew456turner128]

So our brave warrior Simon puts on his super powered spectacles and stares down this puzzle with nothing less than 100 percent determination and says " you've crushed 3 of my testers, but I will be damned if you're going to take down me!!!" So after a bloody battle for well over an hour our hero Simon Anthony stands over a rather colorful but defeated grid and once again claims victory.

[@eridanuskelpi3908]

Your comment made me laugh out loud 😆

[@charliegrant5061]

"I'm sorry I'm not cleverer - It's something I lament all the time but that's the way I was made", says Simon - just after solving a top-difficulty puzzle that stumped three testers. I wonder what percentage of the 349K channel subscribers could solve it at all, no matter faster? Highly complex logic brilliantly (and colourfully) executed.

[@blahhblaah74]

I absolutely agree. I think I am far from stupid, but got awfully stuck on this one. I don't think I could solve this one in a day, while he did it in less than an hour (if you subtract all explanation time). Wow.

[@theskyisteal8346]

It took me almost three hours even with this video to help me get unstuck or to find my errors (both of which happened rather often.

[@Gideons1255]

100% have no doubt in my mind that i would very... very easily have no priblem at all saying that i.... would never solve this let alone in a hr and a half i love these videos its pretty extaordinary that people can solve and comd up with thwse i enjoy watching but know very well this will be above my level always lol

[@alicecold]

Impostor syndrome personified

[@Dragonatrix]

Honestly, I feel like this was *designed* to be solved by Simon specifically. The way he uses coloration to differentiate square options is so unique to him, and that being a core part of the solution path is so specific that I can't see any other way of doing it.

[@MichaelGreen831]

Simon apologizes for such a long video and yet I've been enjoying the solve for the entire time. Please Simon - be as nice to yourself as you are to everyone else. We love your solves.

[@StIdes-wb3ir]

be nice to yourself; love thysolve

[@Varksterable]

@@StIdes-wb3ir That is at the same time the best and worst pun I've heard in ages. And by 'best' I mean 'worst'. And by 'wurst' I mean sausage. Which (no pun intended) means R3C6 is either purple or a 1-2 pair. With BBQ sauce and onions. So by sukofu is vegan and must be green, forcing the 8 in box 5 to feel a bit confused about what to serve box 6. 🤯

[@StIdes-wb3ir]

@@Varksterable I'll take three orders of your finest whatever-that-is

[@Varksterable]

@@StIdes-wb3ir You want 3 orders? Hmmm. That rules out the 4 in box 5, then. And since the snake can't touch itself orthogonally, (naughty snake) the skyscraper clue in column 2 is either (by kropki) a 3, 4, or 4 (again; best not to rule that out), or has a parity of orange. But this means... the end of the thermo in the 27 cage has to make a 5,6,8 triple next to the green star. And has to extend down. Which (by sudoku) means I've quite possibly been watching this channel too much this last year, and that leaving it playing while I'm asleep might not be the best thing to do. But though you can lead a horse to water, you can't make it count sheep. Totaling 45. (OMG that means the domino in box 6 must be a naked 5, green pair!!)

[@paulconway2963]

No need to apologise at all Simon - great therapy for the rest of us - I suddenly don't feel stupid taking forever doing hard suduko! +1 subscriber :)

[@cloudy9592]

Every time he says "Kropki dots" I just smile because Kropki means Dots in Polish :D Greetings from Poland /)

[@madeking4]

Im just imagining somebody from a different country listening to this video, hearing Kropki dots and putting dots on the end in their language so it becomes Dots Dots Dots

[@geli95us]

@@madeking4 I mean, if they are watching this video doesn't that mean they know what "dots" mean and as such they wouldn't need to add it in their language as well? anyway, here you go: puntos kropki dots

[@MichaChaniewski]

Funny thing, I’m Polish too - but at this point I’m practically bilingual. So when I’m listening to Simon’s narrative in English, I’m so switched into this language, that “Kropki” becomes just a proper noun and I no longer associate it with the Polish dots. Brain is a weird lump of jello.

[@aune1674]

@@MichaChaniewski oh same! i didnt realize he said kropki until i read comments

[@gamingimpossibl]

@@geli95us I’ll join too! Puntos kropki dots dots!

[@peateargryfin844]

"I don't want to say anything too soon, but I feel like we're making excellent progress" *still 40 minutes of the video left* Yeah, that's about right.

[@huh968]

how are the two mutually exclusive

[@emilyd8884]

I'm deadddd

[@DBCooperSan]

I tried it, all I could get is that the 45-cage must contain a 123456789 nonuple

[@biankatoth1786]

@@jpryan90 same

[@matthew456turner128]

Shhhhhh thats a secret!!!😆

[@catman64k]

i also tried, i additional got the 3 black dots limited to 1 & 2 & 4 & 8, and the middle tile must is limited to 2 & 4

[@MichaelGreen831]

I solved it in 24 minutes. I’m not counting the part where I followed along with Simon for the first 50+ minutes.

[@thisisnootnoots]

THIS

[@bryanstatz8227]

First thing I do when opening the video is check the length. Today an audible "yessssss." Let's gooo!

[@57thorns]

More like: I had a few days I could solve the puzzles. Today, popcorn and tea.

[@Daximotos1]

100% exactly right

[@malcolmjohnson4414]

I'm sure I have seen this comment on another site but it wasn't one about puzzles 😁

[@truscottlee5554]

Totally agree ... Biggest smile of the day 😂

[@chris5619]

I like the long videos for the entertainment/admiration and the short videos to try the puzzle. I wonder if they track how many people open each puzzle. I'm sure it's correlated to the length of the video.

[@savola3129]

Wow! CTC is coming close to rivaling the Marvel Universe for number of movie releases....I think CTC Universe has better movie titles.

[@timdorr]

CTCCU

[@timdorr]

Make sure you stick around after the credits.

[@andrewgrant6516]

Halfway through Simon's greatest solve, Mark snaps his fingers and half the numbers disappear. He is inevitable.

[@Keldorn01]

The nice thing about movie-length CTC videos is that when they come out, I can give myself an hour trying to spot the break-in, getting absolutely nowhere at all, and then I watch Simon's solve in admiration, and then the video finishes just in time for me to catch Mark's video right after. A perfect evening with perfect timing :D

[@longwaytotipperary]

So a while ago I found this site after trying to understand x wings. And somehow I come back almost everyday and watch the whole thing when most of the time I have no idea what he's even talking about. He starts off with NO numbers and lots of crazy limitations! This guy is just A-MAZE -ING!! And his voice is soothing. I sometimes listen when I can't get to sleep. :-)

[@melaniemoul]

Watched a the first bit of this with my 2 1/2 year old who now thinks “sudoku” is the funniest word of all time. I’ll convert him someday! He can already count to 10, so he’s on his way 🤗

[@chrisfitch972]

He only needs to count to 9 though!

[@NijiRanger]

I hope you will teach him to count only to 9. After all, there's no such thing as a 10 😉

[@Andrewkosche]

No guys he needs to know how to count to 10 for killer sudoku! But anything above 405 is completely ridiculous!

[@ohnoagain2953]

405? Well for the beginning 45 would be enough i whink xD you're right tho, just one step further

[@Andrewkosche]

@@ohnoagain2953 405 is the sum of all digits, so in killer sudoku it can become relevant if there are digits not in boxes

[@ocaly]

this one took me 4 hours to solve but definitely worth it cause this puzzle is the hardest one Ive solved ever. The logic is bea ti ful!

[@ocaly]

Its good that this puzzle is getting the attention it deserves because when I solved it only 7-8 people solved it and like 1-2 comments? Its a quality puzzle. Never expected simon to ~solve~ and upload this to the channel but im happy he did.

[@eridanuskelpi3908]

Holy moly! I didnt even dare to try because of the length of the video and no given digits (which always scares me and I am not yet ready to face that fear ^^)

[@TOJPFC]

I think you’ve said in the past that your testers are anonymous to the viewers, but I’d be really interested to know if they would answer questions about this puzzle. It would be very interesting to know if they were all stumped at the same point, or if this puzzle ground them to a halt at different points. I’m not sure which implies the puzzle is harder actually, that all 3 testers fell at the same hurdle, and therefore three brains couldn’t overcome the same choke point in the puzzle, or that the puzzle had enough challenge that it stopped all three in different places.

[@lDanielHolm]

I actually solved it! It took me, like, two and a half hours... but I got there in the end! I ended up coloring absolutely _everything_ but it worked! I did have to go for some help from Simon, but I solved it after having watched only half the video, and if you check where he is at that point, I think that's still a bit of an achievement. :) I think the key was noticing how the constraints let you map the cells from box 5 out to a few places in the surrounding boxes, which let me do the coloring. EDIT: Bloody... Aaand Simon just proved my solution wrong at 1:14:02. Dammit.

[@taakotuesday]

at least you tried it! I saw the video length and said No, i'd like to go to bed at a reasonable time

[@lDanielHolm]

@@taakotuesday Haha. I was up way too late trying to solve it. It was so much fun, though!

[@btestware]

Me too. That's the exact moment Simon proved me wrong. It was the 4 on the diagonal. It solved the puzzle perfectly, but now that I look at it I see the 9's in boxes 1 and 2 are in a knight's move conflict.

[@lDanielHolm]

@@btestware Yeah, that's the exact same issue with mine.

[@emilioherrera6345]

You know a puzzle has fried Simon when he calls pairs "duos"

[@Jablicek]

If setters keep creating puzzles of this magnitude you'll have to start waking up a day early to get them done.

[@guilded0n3]

I wonder if the lady who failed to know the secret is getting upset about being mentioned over and over in here yet.

[@teyink]

I think it is safe to say that she doesn't follow the channel or she would have known the secret.

[@MichaelGreen831]

@@teyink It's reasonable to assume she's heard about the channel by now.

[@chris5619]

@@teyink The show that aired this week was actually a re-run. The original airing was in 2019.

[@Varksterable]

@@chris5619 Back then, the digits 1-9 didn't even exist. Fact.

[@RicardoRibeiro1978]

@@Varksterable we only had roman numerals. fact.

[@al129]

Come home from work, sit down to watch CTC before having something to eat, sees almost 90 minutes video, decides gets food first and watch whilst eating

[@longwaytotipperary]

ditto

[@JohnSmith-il3iv]

I love the long hard puzzles. They bring me such joy. Please keep up the good work.

[@CubicPhantom]

This one was monstrous to do on my own - 7 restarts across 4.5 hours. It really hit home just how astounding your solve is: stellar work!

[@gms8994]

Black Red Purple Triple would be a fun band name.

[@Jodawo]

There was a technique that was featured on the channel before. It was a technique built upon Phistomefel's Sudoku logic by someone else. If you look at the 5x5 square in the top right corner and compare it to the 4x4 square in the bottom left corner, you can see that the 5x5 is actually the same as the 4x4 minus a set of digits one to nine. If you take out box 3 and box 7 you will notice the killer cage has the 45 extra that if taken it out of the 5x5 it will be exactly the same as what is left from the 4x4. I was very surprised Simon didn't catch that. From that point, it would be clear that you would be working with 6 and not 8 since the Kropki Dots would make it difficult for the numbers that make up 8 to be on them. If you notice on the Kropki Dots there is 1, 2, 3, and 6. The other 1, 2, and 3 are in box 5 on the arrow (that is part of the 5x5 square).

[@krytolandros1775]

That's a great way to open the puzzle! Nice catch.

[@TheSplunger]

This is how I ended up starting it. Boils down to (both kropki) = 2x (the circle). Then kropki sum to divisible by 3, so circle is 69, and 9 won't work .

[@reubenmckay]

That looked brutal. Can't wait for the day we get Simon completing a 2hr solve on the channel.

[@joaoricardo9174]

One quicker path to rule out the 8 in R6C4 is to use geometry to figure out that 2x R6C4 is equal to the sum of R1C5, R1C6, R4C9, R5C9 (the 'top' and 'right' kropki dots). You can't make two black kropki dots add to 16, so it cannot be an 8. To me, the arrows and shape of the box are very suggestive that geometry would be useful

[@ludovicoleporeo2407]

Good catch! Since it took me a good ten minutes to understand, I'll write down the steps for people as dumb as me, but lazier. We look at the cross composed by rows 4,5 and columns 5,6: it adds up to 4x45-R6C4-R4C6. But the left, center and down boxes are 45-R6C4; add to that 45-R4C6 (the cage, except the element we've already counted in the center box) and the two dots. So we have the equation 4x45-R6C4-R4C6=3x(45-R6C4)+45-R4C6+dots, that we simplify to 2xR6C4=dots. (Well, this is how I've seen it. Maybe there's an even simpler way?)

[@markp7262]

58:29 finish. Saw the Aad squares right away, which allowed me to fly through the opening salvo. I slowed down in the middle, and wound up color coding everything for simplicity. Quite an enjoyable puzzle!

[@davidstorrs]

Simon, give yourself credit! You're saying "oh, I'm not clever enough" after doing a stupid hard puzzle! Well done, man. This one was satisfying for me because I actually got it. I mostly went along with you, sometimes jumping ahead, getting stuck, and then going back to the video for some help. Once you started coloring the 5789 squares I was able to go ahead on my own. Of course, I was a lot less efficient about it -- you did some of them, then went to the diagonals and finished everything. I colored every single square (using a silver flash to mean "maybe none of 5789"), unwound everything until I had locked down the 5789 squares, THEN went to the diagonals and sorted it out. Much less efficient than your solution but I did get it on my own. Thank you for all the lessons you've given me; I've really improved as a solver since watching this channel.

[@Sujisan4]

My favorite part of the day.

[@margaretsinclair6697]

If weirdity wasn’t a word before, it is now! And Simon is higher up on my pedestal. Wow. What a puzzle.

[@headoftss]

What a fantastic puzzle. Brilliance layered upon brilliance. Kudos to Simon for getting there and explaining it in terms I could follow.

[@wayneonm.i.fl.6639]

In a pre-emptive strike, Simon invokes the Sinatra Rule!

[@flsal27]

We are going to need to update the criteria for a CTC movie: over 1h or over 1h15. Directors cut coming soon, ie 2h CTC movie.

[@karissajohnson7961]

then we need RELEASE THE (THOMAS) SNYDER CUT and it's 4 hours

[@booxmowo2684]

Release the 4 hour CTC Snyder Cut.

[@4341015]

Adding my stops to think along, it gets to 2h easily.

[@NijiRanger]

Clearly a new all time favourite. Amazing. Such clever and unexpected logic throughout. What really did it for me was the end. I did it a bit differently, where i filled in all the colours before touching the little killers. So i had about half the digits, and then had to consider both killers, think about parity, and see what colours were repeated across them both. Possibly the best use of disambiguating little killers i've ever seen. A beautiful finale to such a wonderful puzzle.

[@ThatLazyyGuy]

47:25 was absolutely fascinating to me

[@glum_hippo]

I was going to bet that Simon would immediately see the application of Aad vdW's trick here. I was wrong! But what a marvelous experience he has provided for us as a result! He basically derived Aad's trick without having to provide an explanation for it.

[@TheLetterJ0]

I found it easier to disambiguate the 6/8 with math. Thanks to The Secret, we know that boxes 2, 5, and 6, minus the killer cage, add up to 90. Then if there is an 8 in the circle, the parts of its row and column that aren't on the arrows (and thus are in boxes 2, 5, and 6) each add up to 45-8-8=29. Subtracting the 8 in the circle, the arrow in box 5 that adds up to 8, and those two 29s from 90 leaves us with 16 for the Kropki dots. And we know that the dots are 1, 2, 4, and 8, which adds up to 15, so that doesn't work. And of course putting a 6 in the circle does work because you instead have 90-33-33-6-6=12, which is perfect for putting 1, 2, 3, and 6 into the dots.

[@laurenstephens1945]

I don’t know why I enjoyed this one so very much - likely because I went the coloring route the whole way through! Wonderfully fun puzzle!

[@WhoStoleMyAlias]

Wow! This was crazy difficult. Totally flunked it on the first attempt where I figured the arrows should add to 8 based on the thought that they couldn't all contain the same digits. On the second run I managed to get the whole grid coloured before even attempting to figure out the math on the little killers and I got the 8 from evaluating odd/even.

[@akamiss99]

I just love watching Simon’s brain at work, it’s pure genius the way he unravels the puzzle. Great solve Simon! You must be mentally exhausted after this one.

[@Arat1t1]

Somehow I managed to intuitively find the logic needed to solve this sudoku, but that didn't stop it from taking 55:18 and required me coloring in way too much. Absolute slugger of a puzzle, and thoroughly enjoyable.

[@raineca]

I know what I am doing after work, with a 1 hour and 20 minute video on the horizon!! Break out the popcorn!!

[@christophstahl8169]

36 minutes in Simon deletes the red colouring that was telling him: Red is 2! Took him 6 minutes to get to that 2 again... Trust your colourmarks! Loved the puzzle. Love your solve Simon. Dang, that was a hard one but i tackled it with colours and i came out on top. So yay for the app with multicolouring!

[@boaconstrictor3754]

There are some of your videos that are twice as short, but are hard to watch. Watching this one was a pure pleasure for me, a big like.

[@Treasier]

This was prolly hardest sudoku I have ever done. Took me 2,5 hours and so much thinking and failing in logic. Already few times I thought I cracked it and then I had to come back. Almost gave up few times. Logic needed was just brutal. I'm fairly sure there is only one way to solve this because I solved it in exact same order than Simon (few deductions were in different order but all the larger logic in same order). Still enjoyed my time very much! Thanks for the great puzzle Miky.

[@brock2k1]

20:22 I kissed her passionately, but I felt that she was holding back. I said, "You're still thinking of Simon, aren't you?" She scoffed, "Simon? He's such a wally."

[@jfirth816]

Brock Savage, my word. If anyone was ever meant to write bodice rippers, it must be Brock Savage.

[@milliams]

*wally

[@brock2k1]

@@milliams Thanks, I know zip about British slang.

[@Varksterable]

@@brock2k1 On "Simon", since you show an interest... I think you'll find that's Celtic "sluhgn" entomologically related to the Norse "S!hlo÷ng-b'jdrn" which was a small pot to keep herring in while voyaging overseas. This is openly depated academically*. "Wally" however was an Anglo-Saxon term for a serf who performed animated, repeatable duties on an ocean going vessel which travelled to distant planets and have some love interet with another, high-born member of society. * not true.

[@Varksterable]

@@brock2k1 Oh, and when you say; "I know know zip about" here in the UK; that means we think you know our postcodes and where they are located. "I don't know zip" means you know nothing to us. "I _couldn't_ care less" means it's something you don't care about. "I _could_ carless" means you do care at least a bit.

[@jaelikesjackalopes]

As soon as we have a black/purple pair and a 4/5 pair in the same square, we know purple is 5 bc we know black is 4.

[@taakotuesday]

was looking if someone else noticed this. Simon's always a little strained near the end, so I'm bot surprised he missed it

[@megansanguedolce7852]

yes i noticed the same thing and i was like “no it can’t be 4!!!!” when he was doing the diagonal 32 in the 7th square of the 2nd bolted box

[@lindseystrickland9305]

Just wondering why that black/purple square that is a 4/5 couldn’t be a 4/5/7/9 square we’re purple is 7 or 9? Or am I missing something?

[@JesteR00160016]

yeah noticed that too, but I thought that this might be an incorrect statement, to say if there are 2 candidates in the cell and one of them is black, and we know that black = 4, then the remaining candidate is 5, is it true to say that purple is 5?? there is a slight feeling that this logic may be erroneous

[@JesteR00160016]

i mean i used it in my solve, but when I looked at Simon's solution, I began to doubt. if the cell would still be 4, can we say that purple is 5. maybe i'm just got lucky

[@Rangsk]

Such a fun Knight's coloring puzzle, with a wonderful SET break-in! If you are looking for more Knight's Move coloring puzzles with impressive break-ins, I definitely recommend "Coloring in for Gifted Adults" by Trevor Tao! You can find it in the discord archive or on my channel :)

[@YayMiko]

Meanwhile, I’m over here struggling with my “light and easy sudokus for beginners” book

[@Jim_Fries]

I absolutely love watching these kinds of puzzles solved, when there are 3+ rulesets.

[@robkuijpers9617]

12:15 Why is that true? If you have three 6s for example then one of the highlighted cells can be an 8. He rules both 6 and 8 out immediately.

[@Kagoolie]

I’m wracking my brain trying to work this one out too…though I’ve seen this solved already (so I’m watching a re-run) I’m still trying to work out how the 68 both can’t be candidates in the seen boxes in boxes 2&6! My brain hurts!

[@robkuijpers9617]

@@Kagoolie Join the club :-) Still don't know. If you have a clue in the future, please share.

[@mariushutu9131]

Hi there! I've been watching videos on this channel for a few days now and it's so captivating that I don't even want to get my work done. It's remarkable the way Simon thinks, and I'm sure he is one of the smartest people on this planet, probably a huge IQ. Looking to get into sudoku as I like these kind of puzzles myself, but nowhere near this type of difficulty. Thanks for the content.

[@Michal_Sobierajski]

WOW! It's over three years of CTC. Keep going and good luck 🤞🏻

[@sirlilcodyjr9927]

So awesome that this was the video my name got mentioned on for the puzzle hunt! Such a fun puzzle hunt and such a fun video!

[@jovaji72]

OMG ! Gonna need lots of popcorn, today

[@davidrattner9]

Make it with extra 🧈 and 🧂:-)

[@bruhnling33]

I used set theory on the opening and it was pretty satisfying but almost underwhelming by how quick it was, after that I got stuck though so yeah. The set theory was the thing with one corner of the grid being equal to the other corner plus one set of digits 1 to 9

[@jeffreytennant]

Nice work, Simon. Just one brilliant solve after another!

[@ryfors]

I really like how everything about this puzzle was difficult, it wasn't just the break-in or the finish - every part of the solve had intricacies. It was also wonderful how you had to reuse the same clue for different parts of the solve. Wonderful setting.

[@BozoTheBear]

This was one of the most enjoyable hard videos to watch on this channel. Many thanks to Miky for the puzzle, and Simon for the solve.

[@thomasburriss405]

For anyone curious when Simon thought he broke the 6/8 and didn’t his flawed reasoning was that the three would be forced on a kropki and into the other square which would rule 3 out of both 8 arrows and break the puzzle. But, as he was explaining he said that the 8 rules the three out of the kropki anyway which is true but threw his previous logic out the window and Simon for a loop

[@achad1607]

I did it! I did it! This is the hardest puzzle I ever solved! I never resolved the 6-8 until I placed a 1 in r5c6. My solution path was roughly, eliminate 48 from the kropki dot in box 6. Place the 2 in r7c7. Set the kropki dot in box 3 as 36, [eliminating the 36 for the kropki dot in box 2.] Restrict the 4 in box 5 to either r6c5 [6-8 resolves to 6] or r5d6 [resolves 6-8 to 8] See that r45 and r8c4 were a 14 double. Then, analyzing where the 1 can be box 3, deducing the kropki dot in box 2 is 1,2, which put a 1 in r5c6, meaning, only now did I know it was 6's, and, not 8's. After that, I didn't figure out the setting of 4's, so took a longer path, but, similar one. On Simon's solve, something helpful is to consider the parity of the 32, and 23 arrows. The repeated digits are always even after doubling. Over ten hours work!

[@Scanlaid]

Bravo!! Amazing puzzle, wow. Hope to see more from Miky

[@dolf370]

A little while ago I thought I would never be able to create a sudoku, two days ago I did create my first sudoku and happy as a lark I am now working on creating my second one. And then I see this. Not happy anymore. The ability to create something like this seems so far beyond conceivable that I seriously consider crawling back into my coffin and asking my altruistic neighbor to dutifully nail the lid shut with silver nails.

[@susanne5803]

I bet the others started like you - only a while longer ago. And congratulations on your first creation! I will start thinking about attempting that in maybe ten years?😁 This here is friendly collective competition! Keep at it: Maybe soon they'll feature one of yours!

[@dolf370]

@@susanne5803 Well, I'm thinking of submitting it to the channel. Might be appropriate for Mark some day when he's in a hurry and wants a 5 minute quicky.

[@susanne5803]

@@dolf370 Please do! They always encourage new setters. And some of us - ehm - slower solvers would be very grateful!

[@Taruby]

Small world. I see a comment from you after stumbling upon your genusdebatten blog earlier this month regarding a comic translator. Had to double check to make sure it wasn't another bloody-toothed vampire by the name of ericcson. Would be a pleasant surprise to stumble upon more familiar names and faces in the Sudoku scene; doesn't feel like anyone in this niche is a bad sort even if their vampire, devil, and totally normal cat avatars may suggest otherwise!

[@dolf370]

@@susanne5803 I will, but I think they are so swamped with puzzles that it's a small chance they pick it up.

[@f0ssig]

"This is true blue" "This is false blue"

[@mightworth3735]

Quote of the day: "that's probably what the answer is but unfortunately probably what the answer is is not how we do things on Cracking The Cryptic"

[@mightworth3735]

Or: "I feel like I have run this puzzle like a flannel, as tightly as I can"

[@elizabethgrosvenor153]

@@mightworth3735 *wrung

[@peterhaagen8506]

I could not solve it. But when I read all the reactions I really would like to see a new video about how to solve it the easiest way using all the input from the comments. Great video. 👍

[@maaleru]

12:41 so now it's normal pencil Marks.

[@jonbrowne8334]

A mystery of total logic! Beyond human understanding! Wow!

[@isavedtheuniverse]

Wow, just absolutely wow. One of the most impressive solves. Some puzzles seem to have a trick to spot whereas this one was an epic grind of slowly whittling down choices and limiting cells. Amazing work!!

[@TaxableLenkoGaming]

I wish Simon got his breakthrough using the Phistomefel squares, I think his reaction would have been awesome

[@stevenbeichner9630]

It took me 3 watches and a lot of rewinding to follow along. It’s not because you weren’t good at explaining, but because this logic was so hard for me. Absolutely wonderful puzzle and explanations through the solve

[@jeffersonroth]

Brilliant puzzle. Colored all the 5789 possibilities and played a little with the 2 given clues outside the grid, and it worked like a charm. 81:39

[@BillLamoreaux]

Glad this video was posted on a Friday. I needed a beer after watching the solve, lol.

[@prahas777]

The deduction at 8 minutes about R6C4 was gorgeous.

[@strakk]

47:45 that 4 deduction is magical

[@harisimer]

if you use set theory its easier: 5x5 grid with the cage and 4x4 grid with the arrows minus their 3x3 box, i will call 5- and 4boomerang: you know 5boomerang = 4boomerang +45, well the cage is 45. So 5boomerang - cage = kropki + digit in the circle = 4boomerang But 4boomerang = 3 times the digit in the circle. So kropki + circle digit = 3* circle digit. Which means kropki = 2 circle digit Kropki dots sums are divisible by 3. So 2 * circle digit must be divisible by 3, which is the case if the circle digit is divisible by 3. So it can be only a 6 or a 9.

[@RichSmith77]

That's very clever. Nicely done.

[@Afterthoughtbtw]

What a beautiful puzzle. I don't think it's the hardest you've ever solved, though. I managed to do the post break-in bit in half the time you did by colouring every single cell in the cage and doing knight's sudoku with the colours. Not a hope I'd have been able to solve this sudoku without the multi colouring ability on your website though! Granted, the break-in bit took me likely at least 10 times the length of time it took you but I'm taking my victories where I can.

[@susanne5803]

Those moments where we feel smart and fast ... 😁

[@corsiKa]

"I don't want to speak too soon, but I am getting quite excited" - 40 minutes left in the video... "I'm feeling hopeful again" - 25 minutes left in the video..

[@DavidVanmeterDutch]

Never tried a sudoku puzzle before but these videos had me want to try. Quite fun puzzles!

[@RajPatel-nq8rs]

Sometimes you hit a stroke of genius that I can barely keep up with and sometimes you have me pulling my hair out screaming at my phone. Always a good watch!

[@chrischalk6213]

I liked this puzzle. Its three tricky puzzles in one! 1) work out the kropki values. 2) determine where the 5 is in box 2. 3) work out the little killer diagonals. After that it’s a nice easy sudoku to the finish!

[@andremouss2536]

18:38 There is a much simpler reason why the central arrow can't be 134 : if so, there has to be a 25 pair in the two cells left, bon one of them is replicated in box 4 by the 1-cell arrow, so this is impossible.

[@RichSmith77]

Aren't there three cells left available in box 5 (r4c4, r5c4 and r4c6)? Two cells if you rule out r5c4 because it mirrors back into box 4. Without the more complicated analysis that Simon does, 5 could be in r4c4 and 2 in r4c6, no?

[@DoddiP123]

Around 1:15:00 when he discovers how the 2x2 of fours is aligned, I found a different, imo more interesting, way to continue. At that point R2C2 is a naked single blue which resolves the blue/pink double in box 3, giving you two placements for pink in box 2 at the left corners, which in turn forces pink to be in columns 1 or 2 in box 1. That in conjunction with pink being in those columns in box 4 as well forces pink to be the pivot digit in R3C7 and from thereon out it's a fairly smooth solve.

[@stevieinselby]

That was brutal ... I'm glad I didn't waste any time getting nowhere with it! Just in awe of the way you can see patterns and know to look for to rule things in and out. You don't need to be any cleverererer!

[@Coldheart322]

Simon, just got to the end. Two things. 1, most of your viewers do not even try if they see an hour+ video, because we know it would take us 10+ hours, assuming we didn't go mad first. So please stop apologising for not being fast. 2, an hour+ video just means watching an hour of you solving, and what is wrong with that? We're not here for a speed solve. Also love the colouring as always :-)

[@Frie_Jemi]

Due to Knight's move constraint, it may be beneficial to color the 1 2 3 sets. Clearly the digit in the center of box 5 cannot appear in the corners of box 4 or 8. But also, what's in the corner of box 4 cannot be in the center of the 123 in box 8, nor can the corner of box 8 be in the center of the one two three in box 4.

[@Ozymandius1977]

Simon discovers purple is 5 at 1:11:18 then uses 4's to back into it at 1:13:37. I really enjoy these videos. I am yelling at my TV in the vain attempt that he will hear me. hahahaha

[@Coyotek4]

Suffice to say, I think this is the longest I ever spent in a single session on one puzzle. I found the solution (albeit with some guesswork along the way), but it took me nearly two hours (1:47:11). All things considered, I'll take it. Insane puzzle! EDIT - the way Simon ruled "8" out of the arrow sum was phenomenal! My guessing '6' there was my big 'guess' in my attempt.

[@milliams]

What a beautifully intricate opening

[@KittSpiken]

That's one crazy quilt you've stitched together.

[@danikanskywalker2119]

The next time there's a brutal puzzle that your testers can't solve, I think it would be the perfect opportunity to do a live stream solve...Would love to see the community's comments and suggestions in real time Don't get me wrong... I love the long solves. But I'd love to see how quickly we could knock it off together

[@dudbike]

Great puzzle and solve!

[@wokkawicca]

Took me many hours over a couple days...I accidentally let the timer run overnight. I got the breakin with the 6's then turned it into a giant coloring exercise, solved it all in colorspace with knight's move and cage exclusion, with only occasional reference to the kropki and LK logic. Didn't really follow Simon's path much; my knight's move tricks were different. Fantastic puzzle but very stubborn. One technique for avoiding confusion when coloring is to "cut" multiple candidates in a box with something neutral like light grey. This makes me aware they are just corner pencil marks. Solid color is always reserved for a resolved position.

[@magnus0017]

I don't know if this is the hardest sudoku you have done on the channel as of today, but I too know a secret. And that is within a month or two there will be an even harder one solved on the channel. And, honestly, I'm waiting for when we got the two part sudoku movie.

[@rankinsean]

Yay, read out my name today for solving the hunt. 😀

[@Tony_Regime]

at 30:20 an easier logical path to follow is that the 3 must be blue or purple from the pencil marks in r1c5/r1c6 and r5c9/r6c9 so red can only be 1 or 2

[@navyblue32]

I don’t understand any of this but it’s incredibly interesting and very good background noise for drawing :)

[@sjm6280]

After noting from several of his videos the property that the double L shape {c5 down until r5 and then to the right + c6 down until r4 and then to the right} contains the lower L shape {r6 right until c4 and then down} plus a set of the digits 1 to 9, and having been clearly given by the puzzle a complete set of the digits 1 to 9 in the double L, I assumed he would state that the single L below contained the digits of the two 1:2 dominoes r1c56 and r45c9 plus the three digits in the central box that are indeed the components of the third arrow departing from the circle in the single L corner From that it would follow immediately that that circle had to be 6 and those dominoes 1:2 and 3:6

[@shteevuk]

"That's not a 9. That's a 9" - Crocodile Dundee doing Sudoku

[@Trunkerad]

I got stuck way sooner than Simon, of course... but I can give one input: the 3 from the center cell was eliminated at 31:30, but it can be eliminated already at 24:20 by sudoku. The center cell "sees" both the top row 3 and the rightmost column 3, so 3 cannot be in the center cell.

[@lizbrooker4635]

Terrific set and solve x👏👏

[@ardemus]

51:38 I like to notate "corner pencil marked" colors by using the color and light grey. In this case I'd color it purple light grey. Obviously, I don't use light grey as a color when I'm doing it.