In Sudoku, The Human Can Still Beat The Machine

[@jaydyer3999]

Inability to see given digits is a very common condition in the sudoku community. I was very surprised at the start to see you solving a completely blank grid.

[@deucedeuce1572]

lol. (He's done it before).

[@emilywilliams3237]

Hilarious.

[@jovi_al]

Thank you so much once again for featuring one of my puzzles on your channel! I always marvel at your kindness and your speed on picking up what the setters have laid down for you. Your solve was exactly as intended, and I'm super happy you spotted it so deftly! The title of this puzzle was not originally "Arbitrary Code Execution", but I had to change it to prevent demonetization 😅. The title of "Arbitrary Code Execution" is because the coloring and the weirdness needed to crack this puzzle open sort of reminded me of the glitchy visuals one might get while doing ACE in games like Super Mario Bros III. Yes, I am a nerd! Edit: I'm also extremely fond of the fact that r12 and r89 are entirely disambiguated with only one given digit, each! If you know anything about classic Sudoku and uniqueness, you know that this is not one of the more trivial tasks to achieve in classic Sudoku setting. Related side note: there are a *lot* of very strange and arbitrary-seeming requirements that are necessary for a Sudoku to be unique-- maybe I'll make a video on that at some point!

[@DarkChasm]

That is indeed fascinating, the whole collapse with a simple deduction... just gorgeous ❤❤

[@mitnehmerrippe]

As a side note for anyone still wondering what Arbitrary Code Execution is: a great example of arbitrary code execution in a video game with a solid explanation for laypeople has been exhibited at a somewhat recent charity event of Games Done Quick, who happen to have a KZbin channel archiving their charity runs as well. Searching for “Games Done Quick Ocarina of Time” in the KZbin search bar will bring you to the video. It’s a technically assisted speedrun where three (or four?) players and one bot enter over a million inputs into an old Legend of Zelda game to program a new bit of code into it and then make the game execute said code. The result has been fascinating.

[@jovi_al]

@@mitnehmerrippe such an impressive showcase! i watched it just a few days after it went live :)

[@BeheadedKamikaze]

@@jovi_al Might we enquire what was the original title of this puzzle? :)

[@jovi_al]

@@BeheadedKamikaze sure! it was called "Quick Kill", in reference to a type of speedrun strat that often gets that name :)

[@msclrhd]

Arbitrary code execution is a computer security term referring to an attacker being able to run any code they want on the target computer by exploiting a software or hardware error. For the puzzle, it is likely a reference to how jov_ial managed to get the solver stuck so that it was performing complex inference chains up until near the end where it found a Y-wing, then solved the puzzle soon after.

[@SirJefferE]

Now the next goal is to compile a sudoku that tricks "Andrew Stewart's Sudoku Solver" into running a copy of Pokemon Yellow.

[@PriffyViole]

@@SirJefferE But can it run DOOM, though?

[@JediJess1]

Let's run Twitch Chat through it live at AGDQ!

[@antosandras]

en.wikipedia.org/wiki/Arbitrary_code_execution

[@aviajalyberth9148]

Dear Simon ❤️ I would like to say that I too use your videos to fall asleep every night. It's not because you're boring but because you make me feel so safe. And i watch the same videos again the day after because it is so much fun. Me and my fiancee usually say "Some people watch football, we watch Cracking the Cryptic!". 😂❤️

[@ragabulle]

I am also currently using CtC to fall asleep for the same reason. I also watch the videos awake 🙂

[@massawassa115]

You guys aren't dull at all man, you just have a calming presence :)

[@longwaytotipperary]

Exactly. They have soothing lyrical voices. And when Simon gets excited it’s the sound of happy magical beings singing in the forest! 🤗

[@onushki]

I ran to the comment section to say this exact thing! I hate to think they might think I find them boring just because I can calm down and relax before falling asleep!

[@CrackingTheCryptic]

Too kind :) Thank you!

[@johnnyshortfor]

I’ve developed severe sleep problems the past few months and these guys are the ONLY way for me to reliably fall asleep 90% of the time. Without them my health in all areas would be much worse so I find it extremely soothing that they’re the way they are! I usually make it about fifteen minutes into a solve and then it’s lights out thanks to Simon and Mark. Best of all even if I wake up in the middle of the night I can count on them to help me get back to sleep!

[@davidrattner9]

@@longwaytotipperary love this analogy you used!!

[@inspiringsand123]

Rules: 05:06 Let's Get Cracking: 05:24 What about this video's Top Tier Simarkisms?! Bobbins: 2x (11:34, 11:34) Phistomefel: 2x (03:33, 04:23) Three In the Corner: 1x (19:09) And how about this video's Simarkisms?! Pencil Mark/mark: 11x (07:05, 07:09, 07:17, 07:19, 07:21, 07:31, 07:51, 13:24, 15:59, 16:14, 16:25) Beautiful: 8x (04:30, 12:35, 12:41, 14:24, 14:37, 19:20, 24:50, 25:24) Sorry: 5x (09:04, 09:52, 12:11, 12:11, 17:00) Obviously: 5x (05:46, 11:01, 12:41, 12:43, 15:34) Ah: 5x (06:36, 09:11, 12:29, 17:04, 21:19) Bingo: 2x (24:05, 24:08) Brilliant: 2x (00:28, 02:36) Fascinating: 2x (24:40, 24:43) First Digit: 2x (24:19, 24:23) Gorgeous: 2x (20:01, 20:04) Come on Simon: 2x (10:04, 11:34) Good Grief: 1x (01:34) Nonsense: 1x (23:58) Clever: 1x (19:24) Naughty: 1x (10:35) In the Spotlight: 1x (19:09) Off to the Races: 1x (15:27) Lovely: 1x (14:20) By Sudoku: 1x (17:06) Shouting: 1x (02:34) Hang On: 1x (16:47) In Fact: 1x (04:02) Full stop: 1x (20:04) Cake!: 1x (02:38) Most popular digit and colour this video: Seven (29 mentions) Blue (12 mentions) Antithesis Battles: Even (2) - Odd (1) Black (3) - White (0) Column (22) - Row (21) 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!

[@haysan32]

There's no way you timestamped all this lol

[@martalucas03]

@@haysan32 It's done by a bot

[@lrvogt1257]

That was very interesting. Lot's of pencil marks but once the first digit was revealed it was fairly straightforward. Fun. I wish you would have a playlist of just Classic Sudoku.

[@davidrattner9]

Love that you feature classic sudoku puzzles still once in a while. Shye and jovial are pioneers in keeping these going!!!

[@Wecoc1]

14:35 The computer says what you've done there can be considered a "Sashimi Swordfish", which is clearly something only the best chefs would be able to cook in a sushi restaurant 😆

[@chitraagarwal8259]

The fact that i did this in under ten minutes is a vindication of how much I've learnt from Simon and Mark over the past year or so! Total gratitude and just the ego boost needed on a Monday morning to kick off the week

[@h4rry4k]

People who would describe any of you as "dull" can be pitied. :-) I often watch your videos at night time shortly before falling asleep, but definitely not because I find anything boring or "dull". Firstly it's shortly after they're getting posted in my timezone. Secondly it's the time of the day I got time to watch any videos. Thirdly and most importantly: Watching your videos really does relax me, it's almost like a meditation. Focusing on one thing and one thing alone, in a structured and calm manner.

[@pinjaheikkinen5738]

Simon, I used to use these videos to fall asleep easier too. Your voice is pure gold and it soothes me so much. However, I can't do it anymore... Because I've learned so much from these videos that I just can't sleep until you've cracked it. Anyway thanks for the amazing content.

[@alantaylor846]

What is impressive (though not surprising) to me is that Simon solved this in less than 17 minutes--while explaining what he is doing!

[@spudd86]

I have fallen asleep watching CtC... but I don't find you dull, your speaking cadence is just relaxing. I do know what Arbitrary Code Execution is, but I don't understand what it has to do with the puzzle.

[@highpath4776]

do tell

[@SourabhDas95]

5:08 for me! I wouldn't have spotted skyscraper logic a couple of years ago but it's just a testament to how good this channel is at teaching advanced sudoku techniques that I didn't even have to pause before my mind jumped straight to 'this pattern must be skyscraper logic'

[@bryanhickernell7189]

You guys aren’t boring relaxing yes but not boring… there’s a big difference there your excitement for the beauty of how the puzzle is arranged is infectious and makes me want to get better at puzzles. I’ve learned so much from you guys

[@pffffffffffffffffft]

I was so happy I figured this one out myself by looking at box 6, and realizing that that no matter where I put either the 9 or 8, there were two squares in boxes 4 and 5 that they couldn't go in without breaking rows 3 and 7 which meant those 2 had to be 7, and the rest of the puzzle solved quickly after that. Then Simon came in and skipped over half my logic with a better coloring method and reached the deduction so much faster. Looks like I've still got a lot to learn from the channel.

[@LixLorn]

Started doing the video alongside you - but I DID get the insight myself! I started coloring the 789s in rows 4-7, and I noticed that if r6c3 matched r5c5 and r4c9, r6c3 had nowhere to go in the 7th row. this was moments before you pointed out that same thing with r6c3=r4c9, I just got to do the coloring faster because I didn't have to be entertaining for an audience. Thanks for the video! Glad I decided to grab a short one today. :)

[@confusedSoulof2010]

Some times I will fall asleep to sudoku solves because your voices are soothing. It's not that you're boring, just that even when you're excited, you're not jolting me awake again.

[@Pulsar77]

I'm working on my own computer solver as a hobby, and yes, this type of visual logic is very hard to program. We as humans are able to get into the mind of the setter. The way rows 3, 4, 5, 6, and 7 are set is striking and we can recognize that it must have been intentional, so we focus on it to spot some sort of pattern. A computer cannot know these things (or at least cannot recognize them easily) so it starts going through all its sudoku techniques until it finds something.

[@jackbrooke9682]

Sometimes I find myself hoping you get stuck because then the videos are longer and I get to spend more time watching but it is satisfying when you work things out so quickly and elegantly

[@willfancher9775]

Whenever Simon shows a puzzle that's definitely not as difficult as the computer thinks, it seems to always involve some kind of coloring. I wonder if the computer could be equipped with coloring algorithms as well. i.e. each cell begins with a unique color, and it over time proves which colors are the same without necessarily knowing much about the digits.

[@craigshea2930]

Ah, but early on, the computer solver actually did use coloring, albeit candidate coloring. I use that technique often on harder standard sudoku puzzles and it can quickly solve a puzzle. The downside of course, for a human, is that coloring takes time. And that’s what makes Simon’s insight really beautiful.

[@iabervon]

@@craigshea2930 What it's lacking is not so much coloring-based logic as the ability to represent cells being unknown but equal as the conclusion of a step and input to the next. If the first thing Simon did was represented as a single chunk up to the point where an option was removed from a cell, it would involve all 15 non-given cells from the middle 5 rows of the puzzle. Simon, on the other hand, can prove that r4c9=r6c6 as an intermediate step whose conclusion he can state and reason from.

[@sanabas1]

You could add it to a solver, but it's probably not going to make the algorithm faster. They work by brute force, repeatedly checking strategies from easy to hard. You can always make corner cases like this one where there's an insightful shortcut to be found, e.g. colouring forces some digits to be the same. But where do you put that on the easy to hard strategy list? Put it too low, and the algorithm won't reach it, because it'll repeatedly simpler strategies (like x-cycles in this puzzle, which is a type of colouring) to eliminate individual candidates. Put it too high, and the algorithm will waste time on proving some cells equal without that helping reach a solution.

[@willfancher9775]

@@sanabas1 I feel like that logic can't be correct because if you applied it to regular sudoku solving algorithms it would imply they never worked. The reason a solver can be efficient is because of the specific strategies that are programmed for it to employ. It seems to me there could be many strategies that involve coloring that are not currently employed by these algorithms.

[@iteragami5078]

@@willfancher9775 there are solving algorithms that run "fairly well" on a computer such as dancing links, but would be awful for a human to implement due to how much backtracking there is. The challenge is to find an algorithm which both humans and computers can use to solve easily

[@woodchuk1]

Aligned Pair Exclusion: Any 2 cells aligned in the same row, column, or box cannot duplicate the contents of any two candidate cell they both see. If the top gray square was a 9, the bottom orange square would be a 7, the top orange square would be an 8, the bottom gray square would be 4, and then the two yellow squares could only be 3, leading to 2 3’s in the second box. So the 9 can be removed from the top gray square.

[@highpath4776]

nice

[@EchoMirage72]

12:00 ... Simon's description of how pretty the puzzle was by making an analogy to RomCom's was hilarious. I do wish I had his wide range of vocabulary in that way.

[@DiMono]

Mittens - the crossover star of our generation.

[@longwaytotipperary]

Loved the thumbnail!! (I can see the resemblance)

[@CuriousChameleon]

Simon, I am a bit behind, so apolgies. But, I also use your videos to sleep with. It's not that you are uninteresting. You are fantastically so. You have an upstanding voice, relaxing with an ASMR quality. The reason we watch this stuff is there is no flashing lights, loud sounds, or distracting concepts. It's totally a compliment to have a video with just learning and understanding without having to sell something every 15 seconds.

[@saki-mk5qi3im2h]

15:20 You could just colour fours (for example with red). 489's in third row will be red-green-blue. We have to put an "yellow" digit somewhere into row 3. It can be only seven at B7 (if bottom left corner is A1 - like in chess notation).

[@PriffyViole]

Got it after 14:27. Had the 7-8-9s colored, but still needed the next step spelled out for me. This probably happened several videos ago (I've been neglecting the longer solves unfortunately), but I noticed Simon made his default green darker. You can do this at home by clicking and holding on the color selection screen until each color appears in an additional box, then clicking the color you want to change. I discovered this by accident.

[@NoodleKeeper]

I am so glad you mentioned this! I noticed his green got darker, and I don't remember him explaining it. My colors look so much better after changing them.

[@ebrahimshayei6220]

I always enjoy watching you tackle difficult puzzles and finding your way to a solution. Your SudoKu-solving skills are impressive.

[@SmartHobbies]

I solved it surprisingly quickly by studying the middle 4 rows and using coloring, much like Simon. I love how Jovial telegraphed where to look with an Oddagon-type pattern in the middle (computer solvers still can't figure those out), giving us the key to breaking in. Wonderful puzzle by Jovial and great explanation by Simon.

[@michaelmele3954]

Simon, if it helps, at 11:30 you were attempting to establish that the number of green digits expected to be in rows 4 and 5 is 2, and if you can show that those two greens are in boxes 4 and 6, then the green digit in box 5 must be in row 6. But regardless of the orientation of empty cells in box 6, you still have no basis for eliminating green from box 6, row 6 anyway.

[@yichen6313]

Very very nice row 3-(4-5-6)-7 interaction! Love a nice classic!

[@cyberrb25]

11:26 it's been tickling my senses that whole connection between the open spaces in boxes 4, 5 and 6 and row 7. They are somewhat interesting because row 7 connects with each at a different row. Maybe you saw part of it, or maybe remember some older puzzles that looked like this concept (don't remember said names, and weren't classic sudoku, but had the colouring at it) and tried to force it.

[@adammunio9633]

5:18 solve time for me on this one. Was able to determine the orientation of the 789s via row 7 and its impact on box 6 if R5C5 was equivalent to R6C3.

[@Alex_Meadows]

Oh wow, that's a brilliant spot. Well done!

[@adammunio9633]

@@Alex_Meadows Thanks!

[@MonkehBuns]

Not dull. Soothing. I watch the new videos but sometimes put on ones I've seen to fall asleep to.

[@robertlong3561]

I love the theme in minor! It sounds like a horror film. I’m imagining a 19th century Simon stick in a haunted mansion until he solves all the sudokus!

[@Coyotek4]

7:33 ... It amazes me that we as humans can see this (at least I did) while computers completely miss such a wonderful break-in. I loved solving this classic!

[@MaritWatery]

Thank you so much for answering my question about the solve video. Maybe Ancient Wall would be great to show here on the channel as well, as you said that Phistomefel considers it his masterpiece and sharing it with a wider audience now that the hunt time is over would be awesome 😊

[@RADZIO895]

17:42 for me, almost decided to get a hint from the video, but in the end managed to solve it myself and I'm pretty glad because that was a really cool solution

[@PotmosHetoimos]

The solve was wonderful but I love the coda of plugging into the machine and talking through the computer's logic as well! Brilliant video all around!

[@DonYagamoth]

Tried this puzzle for ~20 minutes, and didn't feel like I could do anything more - started watching the video and stopped the video as soon as Simon pointed out that there is something interesting with r4c9, and managed to solve it from there. This is fascinating - as soon as I was pointed to the cell I needed to focus on, it was reasonably quick to find the rest Now the next step is to find these cells myself Thank you for your videos, they are always pleasant :)

[@keithmower921]

I was reminded of "Computer says no" (Cobra Roll) which was also by jov_ial. Thank you for showcasing such an amazing puzzle and for explaining the logic so eloquently.

[@Ardyvee]

Loved watching the solve! It really felt like watching Simon try to get something for the rest of the grid out of the rows in the middle, much like you'd try to find a space of memory to smuggle your code away from your box

[@erickehr4475]

“Arbitrary code execution” is a term in computer security where an attacker can get a computer to execute some arbitrary bit of code, often by manipulating where the instruction pointer is pointing to. So I think the title is maybe a reference to how the 789 triples in the middle 3 rows “point” to the gaps in rows 3 and 6.

[@jamesahibbard]

"Dull" is the wrong word. "Soothing" is the right one. I do watch the videos normally, but occasionally one goes on when I'm trying to sleep, because you have a very soothing voice.

[@LavenderGooms]

23: 33 here. That was pretty neat!

[@richardfarrer5616]

The comment edited in is worth an upvote and a response on its own, The use of Mittens in the thumbnail deserves another, but i can't do that. And I haven't even got to the solve itself yet.

[@chocolateboy300]

I finished in 14:36 minutes. For a classic sudoku, that had a surprisingly beautiful geometry in it. The way the middle boxes pencil marks of 789's had to interact with the non-given cells in rows 3 and 7 was incredible to see. I wasn't expecting that in a classic sudoku, but it was amazing. I can see why a computer would struggle. Luckily, I am a human and can see beautiful geometry. I was so happy when I was able to place those 7's. Great Puzzle!

[@diebr0]

We watch and engage from start to finish with your videos, but also put them on to go to sleep, it's like cognitive ASMR.

[@dodekaedius]

Thanks for the input, especially the explanation of your pencil marks

[@branwensloper8197]

OMG! I did it! 27:11. It usually takes me 10 to 15min (and sometimes longer) for GAS. And I can hardly ever make any inroads into Simon's featured sudokus, let alone solve them. Can't believe I did this without even watching video. I used phistimophel and colouring 789s to distinguish. Is that cheating?? Gonna watch the video now to see what I should have done, but feeling pretty hyped....!!

[@emilywilliams3237]

If someone had presented me with that puzzle and said, "It is solvable, and it is beautiful," I would have believed them (especially if they had cited you, Simon), but I am not sure that I could have actually solved it myself. Maybe I would have been able to synthesize all of the logic that I have learned on this channel and, after some weeks of contemplation, I might have been able to do it. Maybe. Thank you for being so brilliant!

[@caitlinerickson7355]

14:00 for me. That was delightful! I love weeding out certain combinations in the middle boxes by comparing them to the gaps in rows 3 and 7!

[@AnnaChiaraBellini]

17'49" for me, I feel pretty happy with it, now on to watching your solve! This was an absolutely lovely puzzle!

[@olegevseev1703]

Thank you, Simon, for the beautiful solve! As for your question about what you were thinking at 11:26, I might have an idea, correct me if I'm wrong: you thought for some reason that if r7c3 is green, then r7c9 is ALSO green rather than NOT green, and that led to the logic about diagonals and placing green in r6c6.

[@uigrad]

The green thing at 11:26 made perfect sense to me. The green digit is the digit that goes in R7C3. We know it goes into either R4C1 or R5C2 in box 4. The unknowns in boxes 4-6 are all on diagonals. It's the negative diagonal for boxes 4&5, but positive diagonal for box 6, which is too bad. If the unknowns in box 6 were on the negative diagonal for box 6, then we would know the green digit would be in either R4C7 or R5C8 for box 6. AND, the great thing about that is that it would eliminate all places in R6 for the green digit except R6C6. It would have been a great way to start coloring your grid, which we all know is your favorite thing to do!

[@RichSmith77]

How are you ruling green out of r6c9, in the hypothetical case of a negative diagonal of unknowns in box 6?

[@crystalgehrt8861]

Beautiful. I'd never have spotted it, but was amazed to follow along and try, and it was so satisfying to finish the puzzle so quickly after that insane Jay Dyer hunt!

[@th.nd.r]

Absolutely lovely!! So simple and elegant and yet difficult to find and so beautiful all around! Take a bow jovi_al, take a bow Simon!

[@longwaytotipperary]

Wonderful puzzle! Wonderfully and entertainingly solved!

[@davidrattner9]

Got to cherish you again using the same word twice. 😁

[@longwaytotipperary]

@@davidrattner9 ☺️☺️

[@AyaAlef]

Simon, we are all still awaiting the *five* missing "3 in the corner" songs from yesterday!... I am absolutely certain they were placed there on purpose :) that puzzle must have broken a record... It's those little rituals that give order and meaning to this chaotic life. Thanks for another video!

[@goncalogarganta2960]

Hey Simon! Love the videos and have been wondering, when you rewatch the videos do you find yourself screaming at the screen when you see yourself make the best deductions and then miss the simplest thing or just missing sudoku etc?

[@CrackingTheCryptic]

I almost cannot watch myself. I totally understand why some people shout at me!

[@SilverKiMak]

29 minutes!!! So happy. Marked up 7-8-9 in 5 middle rows and just reduced by those that made rows 3 or 7 impossible. Great puzzle, good mood :-)

[@markbennet9058]

What a stunning classic

[@RL-gl8qg]

12:35 for me. I don't know why, but it was just intuitively obvious that the central cell had to be that particular digit, because any other candidate starts to leave empty cells all over the grid in just a few steps.

[@Kelters]

Surprised myself with this one. 22:20 !! The clever, clever puzzles fall if you find the right starting strategy. That usually escapes me, except for today !! Thanks for the fun.

[@Qazqi]

My best guess for the title is that the computer solver is doing seemingly arbitrary techniques to solve the puzzle (and bypassing the beautiful logic built in because it wasn't programmed to include this novel technique). Under that assumption, I think jovial would have then come up with a bowtie name that is an established phrase, as ACE is in the software security and glitch hunting/speedrunning domains.

[@HunterJE]

Oh that is clever and satisfying, thank you for carrying me through it Simon because I would never in a million years have found it myself

[@grahamrskelly6042]

Certainly when I started watching I would not have seen that either but with practice I bet some day you will see it

[@tommyozzy317]

I love that you went to the solver to see how it would manage it. When trying to get better at sudoku, i would occasionally go there and try to see what I was missing. This did not go incredibly well. Wonder if your way of solving using a color variable instead of actual numbers would render all those crazy steps unnecessary as far as computing is concerned.

[@andrewnelson2525]

I saw a 26 minute video time and thought, "great I'll get through this fast." Then I saw it was a standard sudoku and thought, "oh no, I might not get through this at all." Given that you don't even do a standard unless there's some obscure trick I haven't seen before, they are far more intimidating to me than any 50 minute variant sudoku video. Took me 20 minutes to do more than eliminate a single pencil mark, and like the computer the first digit I got was an 8, but shortly after that I saw the presumably intended break-in and got all the 7's. Not quick nor elegant, but a win in my book.

[@amoswittenbergsmusings]

Humankind humankind Proudly triumphant when Challenged by silicon Grinding away. Does the computer have Superiority? Jovi-al’s puzzle and Simon say “Nay!”

[@logiciananimal]

Arbitrary code execution is an application security vulnerability when a system can be exploited to run the code of the attacker (with the permissions of the original, etc. - which is often why it is very dangerous indeed). Given how the solver behaves, maybe the idea is that it looks like the solver is just running some attacker code, not what it should be?

[@DIPPY16]

16:33 found it hilarious you did not spot 7 :). The logic was incredible up to this moment. Looking further into it the puzzle just collapses,

[@jamesahibbard]

23:36 A good time, Coloured the 7-8-9 cells in boxes 4-6, once I saw that identifying one cell would identify all of them, and suddenly I'm looking at these 3 cells that had to be identical, ruling out whatever digit it was from the 3 empty cells in Row 3, so clearly it had to be 7, since it already existed in row 3.

[@Vendavalez]

I would like to take this chance to explain why I use these videos to fall sleep and it is not because you are dull. It is because of the reason why I struggle to fall sleep, which is that I spend either some or all of my mental capacity thinking about things to worry and not relaxing so even when I am tired it takes a while to fall sleep. These videos provide two things to focus on which are the logic path you are explaining and the logic path I am trying to find at the same time. This keeps both my conscious and subconscious busy and if I am tired and in a comfortable position I will fall sleep relatively quickly. If your thought process was indeed dull then my mind would start to wander into the kinds of thoughts that make it hard for me to fall sleep. There might be other things, but those are the ones that are pretty clear to me.

[@krimsonnekros3018]

43:05 once Simon pointed out something was going on with the coloring, I was able to Crack in and get rolling. Though unlike Simon I just noticed that yellow was the only color that couldn't go in r3 so it had to be 7 and the rest fell in place the same way for 8 and 9.

[@debrawilden1971]

Did this one, yippee me!! Maybe Mark sent this to you, Simon, because you resist entering candidates in cells? I just went through the #s 1-9, entering when I could see only 2-3 cells for a #. That is when I found certain restrictions for the other #s, placing them in. Then worked out many 2 candidate #s only in some boxes, freeing up single digit possibilities. I did nothing 'fancy!' (Sorry, I'm having trouble fully explaining it.)

[@thescrewfly]

Well, I think I understand what you mean - probably because I did the same or at least something similar. Also the first one I have solved without watching any moves by Simon (or Mark).

[@watchvidjedi]

Can I offer a variation on 3 in the corner? ... When and only when it appears in row 1 the song goes: "That's 3 in the corner That's 3 in the top row Solving my Sudoku" 🎤🎵🎶

[@mashkasart]

could not let myself go to sleep until i got my daily dose of simon solving a puzzle. finally i’ve been saved.

[@piarittersporn]

Great puzzle. Simon, your trick of eliminating the first 7 was very helpful and logically understandable, that I found the solution very quickly and without any further problems. I surely keep the trick in my mind.

[@grahamrskelly6042]

Simon is John Henry holding the machines at bay. Loved the video and the puzzle 18:40 for me

[@JalebJay]

6:31 found the break immediately. Wouldn't call this a mittens' level of puzzle, but would stump a lot of newer solvers.

[@abj136]

Arbitrary Code Execution refers to an exploit in computer cracking where you by unexpected means convince a computer to execute whatever program you (the cracker) give it. This technique also occurs in some video game speedrunning. I refer you for example to youtuber Sethbling who likes to hack supermario games so they can be finished in a couple minutes, basically by using game buttons to program “jump to end of game” into the console, using bugs that exist in the program.

[@TurquoizeGoldscraper]

12:15 for me - I wasn't sure where to start, so I just penciled in 789 in the middle rows and tried filling numbers in until they fit.

[@psymar]

I find your videos very fascinating, it's just your tone of voice is the second most sleep inducing I've ever heard, after the late Bob Ross. I know Mr. Ross worked on making his voice quieter, however, after his time working as a US military drill sergeant!

[@brianarsuaga5008]

Unlike many commenters here, CTC gives me insomnia, as I just can't help but give the more approachable puzzles a try. This one was a nice little ego boost for me, definitely an example of how I've gotten so much better at sudoku watching the channel regularly.

[@jacobroberts5604]

9:03 today, not normally a big fan of classic sudokus but loved the logic on this one! Enjoyed the Mittens shoutout as well.

[@Jopal2222]

The first digit I found was the 4. I noticed that if R3C5 was a 4 it would force a 4 in R9C9 and a 7 in R4C4. Then you will see that R3C1 is a 89, and looks at R3C8 and R4C1 which are also both 89 - but different from each other. Therefore there is no valid input for R3C1. Therefore R3C1 must be the 4. Still had to use Simon's logic from then on, but was pleased I got a digit at first!

[@FryGuy1013]

The diagonal 789s in rows 456 made me think of coloring and I spotted this trick very quickly and I managed to solve this in 11:21. What a great puzzle by jovi_al!

[@nickatty462]

Flippin' 'eck, I solved it. The suggestion here that colouring was the key was all the extra help I needed. Quite astonished!

[@Bonehead777]

I am impressed that Andrew Stuarts software could figure it out at all, but well done Simon.

[@snjyjn]

After the initial goodliffing of 789 / 489, and flailing around for a while, I asked the question - can the 89 in R5C2 be different from the 89 in R6C6 (which would give me 7s in 2 of the other cells). I ended up bifurcating, and coming to the conclusion that they cannot. Once they were the same, I was able to break in - but I needed to bifurcate, and Simon was able to see this without that! Just amazing!

[@StephenMarkTurner]

I could handle Mr Grumpers. Catspurrov not so much. Mittens, forget it.

[@BookofAeons]

11:25 It's okay, Simon. Hard classics drive me mad, too XD

[@adriandowinton5722]

Does anybody know the name of the song Simon uses for the outro music please ?

[@FilmscoreMetaler]

Wolfgang Amadeus Mozart - Piano Sonata No.16 in C major, K.545 - I. Allegro (version edited by Brennan Arceneaux to c minor)

[@adriandowinton5722]

@@FilmscoreMetaler thank you very much for the reply, I've listen to the Piano Sonata No 16 a few times and can hear the opening music but can't hear the outro section from time 56.15 to the end, I presume that must be the edited bit by Brennan Arceneaux. I was sure I recognised it.

[@FilmscoreMetaler]

@@adriandowinton5722 Sorry, my understanding was that you wanted to know the title of the original piece by Mozart. The specific composition used in Simon's outro is a variation on the theme done by Brennan Arceneaux. I wasn't able to find the composition on KZbin or Shazam, but you might want to reach out to the composer via YT or other social media platforms.

[@NoodleKeeper]

At 11:20, you were talking about the fact that if the 789 pairs had all faced the same way, you could have used logic to determine the purple 89 cell was also green, but because the triple in box 6 went in the opposite direction, it didn't help you in that moment.

[@WhoStoleMyAlias]

Interestingly, I only spotted the (your) yellow cell restriction after finding that (your) blue could not be 9 (hence needed to be 8) because that would lead to 8 being forced into both r1c6 and r6c6. When yellow came to my attention I actually at first thought I had broken the puzzle and was truly relieved when I realized that 4 came to the rescue.

[@stevesebzda570]

That was it (@15:28) That sorted the corners from the Phistomefel ring. [1s ("Aces") included] Cool 😂👍😎☕️☕️

[@Arkhanno]

Arbitrary Code Execution is a phrase pertaining to injecting and executing a command or code. It allows you to run any code you wish. If you want to see this in action and be entertained while doing so I recommend you check out TASBot from the GDQ marathons. While this isn't necessarily just a speedrunning thing, it is one of the more entertaining (and non-abusive) ways you can see and understand it. To explain it a little more properly: an attacker finds a flaw in a system that allows them to run any command or code they wish.

[@Stettafire]

3:00 I confess to being one of those people. In my defence I also find it very educational and I generally solve a classic every morning. Not dull, but relaxing :)

[@ilonachan]

The really fun thing here is that while the computer rates this 380, if you place a given 7 in R6C7 this also implies the beautiful first step, and suddenly the computer thinks it's 42 (nice) and Easy.