The Sudoku That Tells You Where To Place Digits!

[@kamalidimock8726]

This time last year, I was battling cancer. During that time, I discovered this channel. Through all the surgeries, treatments, etc., I never missed a day with CtC. One hour (or more) of Simon and his impeccable logic, quirky humor, and 3s in the corner made everything alright again. Almost a year cancer free. ❤

[@gatlygat]

Lovely comment. best wishes for your future safety and happiness

[@kamalidimock8726]

@gatlygat thank you so much 💓

[@wanderlustwarrior]

Congratulations!!!

[@CrusaderPuzzle]

Hello Simon and thank you very much for the feature! Great solve, and you did find all of the intended path! I loved exploring some of the uncommon variants, and making it interact in a new way. When I set 6x6 sudoku of this ruleset, I realized specific placement of the pills, can't index themself and limits X & Y. Exploring it more, resulting in this puzzle! Thanks for the kind words and hopefully everyone enjoy the puzzle and video as well. :)

[@davidrattner9]

Fabulous from you Crusader175. Pleasure to see set with beauty and great logic!!

[@trainzack]

I very much enjoyed the puzzle. Thank you!

[@KSilverlode]

I enjoyed this puzzle a lot! Thank you!

[@mbakenemdusink9757]

Thanks! Dispite a bit too hard for me to solve without peeking at Simons solve a couple of times, I loved it

[@DamienJones-um7cr]

This was a lot of fun. I am unsure exactly what the major break through was intended to be, but for me.... Break for spoilers... Pill in row 3 could.not be 46 because r3c3 and r4c6 saw every digit from 1 to 9 in some way. Beautiful flow from there.

[@pseudomonad]

You deserve people being thankful! Your videos are an excellent refuge from a harsh world, and it's lovely how positive and warm you are to the community of setters and solvers alike.

[@brianj959]

I agree. I do occasionally shout at the screen - as Simon generously excuses from time to time when the given digits appear as translucent to him as water - but putting that aside, his and Mark’s generosity to setters, solvers, and this community is constant, warm and inviting…which is why I keep coming back to the channel day after day.

[@pseudomonad]

@@brianj959 Exactly. I love these videos, especially when they're kind. And they're _always_ kind.

[@wordclover]

@@pseudomonad Well put!

[@callumvlex7059]

I feel like Sven should add a Simon mode where given digits are blue

[@jensschmidt]

Circled in red, permanently flashing

[@donaldsnyder1543]

​@@jensschmidt I was going to suggest flashing neon , possibly with an alert noise as well.

[@olivier2553]

I think it is not a problem of colour. I think Simon solves most of the puzzle from the model he builds in his head, from whatever deductions he has been doing at previous steps. As the digits are given, Simon had not done anything to solve those digits, so they have not been built in his mental model.

[@callumvlex7059]

@@olivier2553 yes, that's obviously true, it's just a funny idea

[@krisdelacourt3977]

Simon mode is when all given digits are invisible

[@dollarsing]

Other than the fun of solving (or watching you and Mark solving) amazing puzzles, the channel succeeds because you and Mark are both interesting personalities with normal silliness going on in the background of your homes like Maverick, noisy neighbors, quirky light bulbs, wearing the wrong glasses, and so on. It's all very charming!

[@minokawasun]

i work at a very large airport and as you might imagine it can get very chaotic this time of year for the holiday season. this channel has been a good refuge to unwind with after work, and for that i am very thankful. you guys might not be flashy like other youtubers and only do “puzzles and birthdays”, but the consistency and genuine enthusiasm for what you guys do is what makes this channel something that i look forward to seeing on my feed! happy holidays!

[@gatlygat]

So true. A distillation of good and joyful. Best wishes to you

[@chocolateboy300]

I finished in 38:56 minutes. These puzzles that utilize indexing in creative ways are so fun to solve. I really liked the way this one worked by limiting 5 off the modular line that allowed 28 to create some interesting restrictions. I also liked how a phantom positive diagonal formed. This was fun. Since it is Thanksgiving, I must give my thanks to Simon, Mark, and the CTC community. They have greatly been a source of joy in my life. I hope one day that I am able to contribute to this channel and finally construct my own sudoku. Thanks, CTC! Great Puzzle!

[@LastShade]

Hey Simon, American here! Thank you for the warm wishes! I really appreciate the mention, and wanted to stop and say I absolutely love your content! You have a wonderful presentation style, and a brilliant mind. I grew up playing sudoku and the variations you play are truly fun to watch be unraveled. All this to say, thank you! I’ll devote a special thanksgiving thanks for all you do!

[@davidrattner9]

For those celebrating today...happy Thanksgiving to all. Grateful and constantly thankful for you Simon and Mark, your amazing channel ,entire content , who you both are as people and to this wonderful community.

[@AditaBattleForge]

gosh, I love this puzzle! At first I had no idea how to tackle this, but once you find the break-in, it's a solving spree! What a discovery!

[@jessicathompson8389]

Thank you so much! This puzzle was just over the edge of too hard for me, and it was fun to get as far as I could, watch you solve for a hint, pause the video and continue solving on my own. You are lovely at explaining your thought process.

[@A_CC_K]

This puzzle looks interesting. I say this a lot but watching CtC is the best way to spend an evening or a morning or whenever you want something brilliant and relaxing.

[@drlabos]

I can personally attest to the fact that this is the best channel on KZbin !

[@KSilverlode]

I am thankful for CtC every day. Thank you Simon and Mark for continuing to grace us with a puzzle each day, presented with warmth, humor and wit. I look forward to it daily!

[@xerodeus2337]

01:04:59 Solve Time! I was floored that I got the entry point for this puzzle, the way it all worked, this was definitely a clever puzzle but very do-able. Wow, this felt super rewarding!

[@fiona4450]

I discovered this channel during covid. This is my most-watched channel. I will say that if certain *other* channels I like put out more videos they'd be at the top of my list, but they don't post videos every day, or even every week. I do like sudoku a lot, though I'm not very good. I've gotten better watching your channel though.

[@roccov3614]

I was starting to think I'd never get this one but today everything fell into place, and I completed it. Nice puzzle.

[@jaeusa160]

@31:40 I like how "Chocolate Teapot" is now a term for when 3 digits in 3 positions are all uselessly reduced to unique pairs of said digits.

[@andymoss]

18:37 “We’re getting some quite crazy colouring going on here”. Quelle surprise!!! Great puzzle and solve. Happy Thanksgiving.

[@avrywilson577]

Devilishly challenging. Wonderful, this one. Thanks Simon and Crusader!!

[@domanski123442]

I like when Simon makes sort of a rainbow in the grid using his solving color techniques

[@ChadEichhorn]

oh i quite liked this one! everything clicked so nicely. 36:15

[@xerodeus2337]

Happy Thanksgiving Simon! It's a very tumultuous time for us here in the US right now and we're working hard to remind ourselves what we're thankful for as we brace for what's next.

[@HalfBakedLunatic]

As soon as I saw the rule set, I just loved the concept .... excellent setting and great video!

[@abergdahl]

For once I found a completely diffrent path, i deduced that the dark green 28 in r5, c5 could not be indexed to r4. c3 since it would clash with another dakr green 2&8 and therefore that middle 28 had to be r9,c1. by doing that i got the order of the modular line and it ran VERY smoothly from there.. REALLY great puzzle, and yes I am a programmer type of person ;-)

[@Paul-cn3ij]

Really enjoyed that. Just over 1/2 an hour to complete. Skipping through the video, I don't think Simon did himself any favours with all the colouring. I stuck with just the modular colouring until I'd broken the back of it before removing it all. Made it easier to spot the logic especially in box 5 imho.

[@Cymindis]

I enjoyed this puzzle once I got my head around things a bit!

I realise my comment could be inerpreted as if I had something to do with the puzzle, which I have not. I'm just enjoying the show.

[@ericpraline1302]

Interesting, thanks. I had a bout of Simonitis whereby I completely overlooked the givens.

[@gatlygat]

Really delightful and tricky puzzle. So good!

[@DjurslandsEfterskole]

Gorgeous puzzle!

[@crashtextdummie]

Such a cool puzzle, all the logic felt really unique. Especially loved the break-in!

[@grahamania]

00:43:03 for me. Great way to spend a holiday evening with such a wonderful puzzle! Kind comment.

[@roccov3614]

35:18 What I realized at this point is that the referred to 2 can't be in box 3 because of the existing 2. So it must be in box 7 and can only be r9c1 because r7c3 sees 2 and 8. Now there is no place for the 8 in box 7 so it must be in box 3. And because we know it is pointed at by a similar modulo coordinate as 2, it must be at r3, c7. Which, of course, Simon figures out later.

[@compiling]

Solved in 29:20. That was a really interesting interaction between the modular line, Xs, indexing cells and negative diagonal rule.

[@JackBongos]

thankful for threes in the corner

[@troymcdougal9010]

You should never take any comment we make personally! I could believe I am an absolute numpty because, even though I have been watching since COVID, I never noticed until You expertly explained that the modular line numbers are the vertical rows on a number keypad. But no, I don't feel a numpty, I feel I now have a very powerful tool when it comes to dealing with modular lines.

[@piarittersporn]

Brilliant and very exciting puzzle.

[@danidracogal]

My first time trying the puzzle myself, solved it in 66 minutes, although I did get food in the middle, so idk what my actual time was lol. This was a super fun puzzle

[@evanbasnaw]

I am thankful to have another cracking the cryptic video to watch on this Thanksgiving day. I did also celebrate with some Death by Chocolate desert. I would think that's something that would appeal to Simon.

[@paula-zzz]

i really enjoy ctc, thank you for providing me with content to calm down and relax to every single evening :) oh, how blessed we are

[@fajenczowiek7443]

Whoa, amazing work! ❤

[@darthrainbows]

I wracked my brain over this one, and was struggling to make any progress. I don't even know how I finished it, but I had 3 or 4 times in the puzzle where a "what if this..." thought just entered my head, and that thought led to a contradiction that forced some constraint on the grid. I feel like I just got lucky rather than understood the logic of the puzzle. "Solved" (if you can call finding a solution without elegant logic) in 72:10.

[@Renigade68]

It was interesting watching this cause I went about it completely differently, your light/dark green method with the 2/8 pair was definitely the faster solve overall, but I actually realized that the 2 went in the bottom left almost immediately as one of the first things cuz I realized that due to the given 2's position the only place for 2 to go on the positive diagonal if it was being indexed was the bottom left corner, and if it wasn't being indexed then it would have to be in row 2 column 2 in box 1 due to the negative diagonal rule, but that would force it into the bottom left corner anyways due to normal sudoku, and then I went from there ruling things out and eventually arrived at the correct solution but in a very different order, so when I watched the video and saw you point out why 2 and 8 both had to be indexed fairly quickly it was rather humorous, I could have skipped a lot of steps in my solve if I had just realized that sooner haha.

[@DaveLeCompte]

So unfortunate that it's row X, column Y, which makes the x,y coordinates reflected from the more traditional x:horizontal, y:vertical association

[@Kairamek]

It's how programs are written. Coordinates when drawing on a screen start at top left. I think it's because that's how CRT tvs drew the picture.

[@DaveLeCompte]

@@Kairamek I'm not talking about the origin, that's whether Y is up or down, I'm objecting to the instructions saying that 1,9 is row 1, column 9, which is in the top right, but is notated with x=1, y=9, which is needlessly confusing, when most 2d coordinates would use x as the horizontal coordinate and y as the vertical coordinate. Better not to even use X,Y, but instead R,C in the instructions.

[@Kairamek]

@@DaveLeCompte oh yeah, that's totally wrong. Should have stuck with R and C

[@niamhcostello4766]

Thank you for another great video!!❤

[@ivandegeweldige]

28:28 *VSauce music starts playing*

[@PeterFreese]

I followed a slightly different path to starting: I eliminated 5,5 and 6,4 from the positive diagonal; the 6,4 was impossible because it would have ended up with a 6,4,6 in the pill, thus showing that the 1,4,7 row indices were the tripled numbers on the modulus line.

[@ChappersDave]

Must be my computer programming brain from 20 odd years ago but spotted a row indexing to do with the 369 set after a few seconds.

[@valeryolympia]

57:01, similar time as Simon! Personal achievement for me hahaha :)

[@n_mckean]

Wuthout writing 1000 words, I thought I'd mention a piece of logic that helped me early that if intended I thought was very nice and that is the relationship of the pills in tows 5&6. When you realise they both have to start with 1379 and that they come from alternate moduli, the beautiful part is that if the row 5 pill starts with a 1, then the other pill must be a 3 or a 9 - BUT the 1 needs a 9 to go with it, so that leaves only a 3. The short observation here is that it means that both the values in r5c5 and r6c4 must be in the same box (either box 3 in row 1 & 3 or box 7 in row 7 or 9). This eventually leads to r5c5 having to be in position 9,1 which fills in the pill

[@blackmoonroze9336]

I keep being impressed by how you make the most complex deductions but then fail to see the simple sudoku parts... cos who would play sudoku in a sudoku puzzle, right? hahaha

[@srwapo]

Well, I gave this a try, used the video for help putting 28 pairs in Box 5, got kinda stuck again, then the timer jumped to like 160 minutes (unpaused when I put my phone in my pocket?), and then I accidentally opened a link in the tab I had the puzzle open on and it was reset when I went back. Watching the video!

[@phuybrechts6875]

A given 5 , Yes he says . And then ignored it in box 9 😢😊

[@FryGuy1013]

The way I solved this one (at the point about 18 minutes into this video where the 28 pairs on the blue line were determined) was to notice that 2 and 8 were forced to be Z digits in box 5 and 9, by pigeonhole + blue line logic, so therefore there must be a 2 on what Simon marked as purple. The only place that is possible is r9c1 so 2 in box 7, 2 in box 1, 2 in the 28 pairs and it gets a lot easier from there on.

[@leefisher6366]

4:41 - That isn't the secret, Simon. The secret is... ... 45.

[@titirenee]

Titi's Time: 35:30

[@flabort]

I need a puzzle with a mod-4 line on a 16x16 grid. Sets would be [1,5,9,13], [2,6,10,14], [3,7,11,15], and [4,8,12,16]. It would have to be 4 consecutive digits along the line to achieve the same sort of repeating pattern, since there are 4 sets instead of 3. And whomever sets it, and whatever additional clue types are on the board, Simon must solve it on video.

[@tBagley43]

1:08:23 very fun breakin :)

[@Pablo360able]

This one took me 35 minutes to fill in a single digit, and then 30 minutes for the entire rest of the puzzle. Plus one false start because I foolishly carried out a bit of logic from a prior calculation that didn't apply in the new circumstance because box 3 contains a 2 but not an 8. Since I noticed pretty quickly the correspondence between modular groups, positions within boxes, and the indicated positive diagonal, I jumped straight to coloring the boxes on the negative diagonal that were part of the pills, which I think was indeed a much nicer coloring.

[@nathanmays7926]

I am thankful for the amazing CTC discord community

[@Paolo_De_Leva]

*Incredibly smart* cosmic class design‼ I am impressed, yet again. How can someone even imagine such an intricate interaction between four types of constraint? 🤔 For instance, you start solving by understanding that by *X* logic *5* cannot be on the *teal* line, and there cannot be two *pills* that point to the same cell, otherwise the digit in that cell would repeat along the *blue diagonal.* Hence, by *X* logic the digits along the *teal line* must be different as well. This rules *2* and *8* out of the midpoint and endpoints of the teal line, which by definition must belong to the same *modular set* and by the above mentioned *X* logic cannot repeat and cannot contain *5...* This is a fascinating indirect connection, mediated by *pills* and by *X* logic, between the *blue diagonal* and the *teal line.*

[@4thright]

1:55 Trust Simon to pick an example that would index a 3 in the corner, only to fake us all out brutally by not putting it in!

[@fdlatyt]

I am imagining someone setting the puzzle and in the end noticing there is no 3 in the corner, shaking his or her head and starting over

[@Gonzalo_Garcia_]

22:43 for me. Quite a tough one imo, but very enjoyable as well!!

Hello everyone! Happy solving!

[@Paolo_De_Leva]

Thanks. Weirdly, your name does not appear 🤔

[@ChappersDave]

@@Paolo_De_Leva because he does not have a 'display name' set i.e. no @DisplayName in his profile

[@ozargaman6148]

What's the origin of 3 in the corner?

[@raccomunk1717]

Took me a bit to get started but finished in 36 min

[@leefisher6366]

Simon (or Crusader 175), is there any relevance to the fact that on the corners of each box on the negative diagonal, those digits also sum to 10 each time, or is this a coinkidink? (We have [3,7], [4,6], [1,9] from left to right, top to bottom).

[@CrusaderPuzzle]

I think it just coincidence. It just happens to be the case since the modular lines is forcing a lot.

[@leefisher6366]

@@CrusaderPuzzle Thanks, Crusader. I'm glad for Simon's sake there was a three in an actual corner for him.

[@5t757]

39:46 for me, found this one pretty vicious

[@lynnfarmokie7553]

Chocolate teapot isn't a thanksgiving food

[@mstmar]

simon mentions this every time, but i wonder how many programmers actually find the indexing part easy. i've worked as a programmer for about 10 years and i dont feel like it helps with the indexing

[@Paolo_De_Leva]

I wrote tons of software, including functions that multiply multidimensional arrays, but I believe being familiar with indexing is not important at all in this case. First, you do not need to be a programmer to understand 2D Carthesian coordinates. Second, there is so much more you need to understand to solve this puzzle‼ You need predictive skills to understand intricate interactions between four types of constraint. For instance, you start by understanding that *5* cannot be on the *teal* line, as it is incompatible with the *Xs,* and there cannot be two *pills* that point to the same cell, otherwise the digit in that cell would repeat along the *blue diagonal.* Hence, by *X* logic the digits along the *teal line* must be different as well. This rules *2* and *8* out of the midpoint and endpoints of the teal line, which by definition must belong to the same *modular set* and by the above mentioned *X* logic cannot repeat and cannot contain *5...* This is not just indexing logic. It is a fascinating indirect connection, mediated by *pills* and by *X* logic, between the *blue diagonal* and the *teal line.*

[@mstmar]

right, this puzzle in particular has really mild indexing, but i was talking in general. my experience with multi dim arrays never helped in any 159/other indexing puzzles that i can remember

[@Paolo_De_Leva]

@@mstmar Like you, I don't feel particularly good in indexing puzzles, especially as compared with Simon and Mark.

[@Кристина-е2в1ю]

Thats three in the corner ~

[@philc2729]

Don't second guess your coloring. I thought it was a clever way to differentiate the digits.

[@Holzpenner]

🎉

[@haniapopowska8966]

❤

[@przemekmajewski1]

Simon WOULD NEVER color a GIVEN 2 dark green (or dark/light green)... NEVER

[@TurquoizeGoldscraper]

32:27 for me.

[@ChappersDave]

I wish Simon would learn to use pencil marks lol

[@angec9908]

Turducken IS fun to say but it is an abomination 😂

[@douglasrogers3918]

I just hope that one day you will insulate your attic properly, keeping it warm in winter and cool in summer. Oh I can hope that the building regulations or something forces us to make this right...

[@stephenbeck7222]

Simon’s attic is now his permanent workspace. It got him 600k subs, he can’t abandon it or upgrade it now. 🤣