The Sudoku You Cannot Use Sudoku To Solve!!

[@Stylpe]

Thank you so much for featuring my puzzle! I'm still watching, 41 minutes in and I've been giggling the whole time 😁 You're doing great!

[@longwaytotipperary]

Giggling is therapeutic!!

[@kf7872]

Got me chuckling with the rules - a good start 🙂

[@livedandletdie]

It's a very difficult puzzle, I'm baffled over how beautiful it was set. And for anyone who doesn't know 21 is a very magic number...

[@Timlagor]

Huzzah for note taking space!

[@CowCommando]

Thank you so much for adding the space for notes! A great many puzzles would greatly benefit from this, but it's almost never used.

[@SourceOfBeing]

A Sudoku puzzle where you can't use sudoku. This must be Simon's favourite puzzle.

[@kotzkica]

I like your profile picture

[@qencu9041]

​@@kotzkicaand I like yours

[@phuybrechts6875]

But his scanning is still terrible 😅😢😂

[@penningmeestercgkdelft9159]

What a nice final challenge does the rule set contain! 🙂 Let's see... The secret of adding up the numbers 0 to 11 is 66. Every row/column/box must add up to 45, so each set of numbers should miss out 21 worth of numbers from its set, divided over 3 cells. The sequence 1 to 9 is forbidden, so the combination 0/10/11 cannot be missed out. Hence every legal set of 9 numbers must contain a zero. Then, the following combinations of numbers could be missed out: 11/9/1, 11/8/2, 11/7/3, 11/6/4, 10/9/2, 10/8/3, 10/7/4, 10/6/5, 9/8/4, 9/7/5, 8/7/6. So I believe that there exist 11 valid sets of 9 numbers in total.

[@jaeusa160]

It's funny that Simon struggled a bit to see it in the way he taught us to see Sudokus, which is using The Secret.

[@iceberg54321]

Good job with the bonus question.

[@jonh6585]

Is it unique combinations or permutations Eg. Is 01345679A different row from 34567901A

[@jonh6585]

Another way of thinking of it is the valid number of 2 digit 10 and 11 killer cages and 3 digit 21 cages (which is basically what Simon did (4, 4 and 3 respectively)

[@ilsekleibscheidel7219]

You can get the 11 possible sets by thinking like that: The sum oft he missing numbers is 21 as was mentioned above. If you are missing A and not B, the other missing pair (addng to 11) has to be chosen from 4 possibilities: 29, 38 , 47, 56 If you are missing B and not A, the other missing pair (adding to 10) has to be chosen from another 4 possibilities:19, 32 , 43, 46 If you are missing both, you have to miss a triple adding up to 21. Simon mentioned several times, that this can only be 984, 975 or 876. So there are 4+4+3 = 11 possibilities to choose a set fort he rows, columns and boxes.

[@minamagdy4126]

Finally, a puzzle where Simon struggles just as much to put in naked singles as I do in a regular sudoku

[@artemisspawnofzeus7732]

@@minamagdy4126 i struggle with fiding any naked singles near me too.

[@prodigis.]

This is one of the most "how did they make this" puzzles of recent memory

[@Stylpe]

That's actually a bit of an interesting story to tell! I used a constraint programming tool called Conjure and its programming language Essence to generate solved grids. Then I hand crafted the puzzle by starting with a blank grid and looking for interesting solve paths.

[@prodigis.]

​@@Stylpe Thanks for sharing - it came out very interesting indeed. And once you get used to it a bit it points you pretty intuitively to the first three columns as a starting point. Nicely done!

[@Playmaker6174]

What a surprise to see this puzzle on here, considering I was in fact one of those 6 solvers on LMD and even I was terrified of what would happen if it actually appeared on the channel haha Regardless, once you finally got into the flow and (somewhat) understood how the rule set works overall, it's a rather satisfying puzzle with plenty of cool arithmetic deductions, and quite mindblowing how it even resolved at the end x)

[@inspiringsand123]

Rules: 06:33 Let's Get Cracking: 09:53 Simon's time: 1h14m28s Puzzle Solved: 1:24:21 What about this video's Top Tier Simarkisms?! The Secret: 7x (01:17, 01:20, 08:23, 08:48, 10:30, 10:42, 19:07) Bobbins: 4x (27:56, 27:56, 31:10, 57:12) Three In the Corner: 1x (56:49) And how about this video's Simarkisms?! Hang On: 13x (12:14, 12:24, 26:04, 26:04, 31:32, 35:51, 46:00, 49:11, 49:11, 49:11, 1:11:45, 1:17:14, 1:17:39) Ah: 13x (17:06, 17:55, 25:23, 25:54, 28:19, 31:10, 37:12, 46:00, 46:19, 49:11, 51:37, 1:05:14, 1:10:14) Sorry: 11x (05:33, 14:44, 20:00, 34:43, 35:06, 35:20, 37:12, 43:44, 1:11:49, 1:12:41, 1:21:18) Pencil Mark/mark: 11x (18:16, 44:35, 44:57, 47:45, 48:10, 50:20, 1:06:42, 1:12:13, 1:16:33, 1:16:36, 1:19:44) By Sudoku: 7x (29:18, 32:18, 48:20, 48:27, 59:40, 1:12:06, 1:20:33) Brilliant: 6x (00:33, 1:07:05, 1:23:04, 1:23:07, 1:24:36, 1:24:39) Lovely: 5x (33:08, 56:45, 56:45, 1:06:03, 1:20:57) I Have no Clue: 4x (38:12, 44:46, 1:09:14) Bizarre: 4x (00:19, 20:49, 22:32, 22:34) In Fact: 4x (16:17, 29:07, 30:29, 1:05:38) Obviously: 4x (05:19, 11:50, 11:53, 1:24:02) Whoopsie: 4x (20:17, 20:17, 53:38, 53:40) Weird: 4x (01:44, 12:24, 17:50, 56:05) Good Grief: 3x (46:23, 1:11:57, 1:24:27) Goodness: 3x (1:12:37, 1:24:16, 1:24:20) Clever: 3x (18:33, 40:25, 1:07:05) Lunacy: 3x (37:51, 37:51, 45:23) Cake!: 3x (05:09, 05:19, 06:01) Useless: 2x (34:01, 1:01:49) Naked Single: 2x (50:01, 1:21:03) Beautiful: 2x (02:30, 49:22) Break the Puzzle: 2x (1:08:20) Bonkers: 2x (01:01, 01:04) Wow: 2x (40:03, 1:20:37) What a Puzzle: 1x (1:24:20) Bother: 1x (57:59) The Answer is: 1x (1:16:46) Out of Nowhere: 1x (1:02:35) Nonsense: 1x (1:21:56) In the Spotlight: 1x (56:51) Fascinating: 1x (00:57) Incredible: 1x (41:25) Gorgeous: 1x (1:11:57) Come on Simon: 1x (1:19:09) Shouting: 1x (46:32) I've Got It!: 1x (1:23:08) Box Thingy: 1x (1:02:25) Phone is Buzzing: 1x (32:18) What Does This Mean?: 1x (38:22) Triangular Number: 1x (10:45) Most popular number(>9), digit and colour this video: Ten (22 mentions) One (100 mentions) Green (14 mentions) Antithesis Battles: Even (9) - Odd (2) Row (80) - Column (75) 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!

[@derekstanyer]

This is the best I have ever felt about solving a sudoku, and it’s probably the hardest one I’ve done. I developed my own system and it took me an hour and 40 minutes. Such a good feeling to get through it without messing up somewhere along the way!

[@johnpauladamovsky86]

This puzzle was some kind of mathematical discovery for the ages... BRAVO...!

[@srwapo]

@50:10, "This is digits. All of this is digits." I always learn something new about sudoku watching these videos!

[@ingiford175]

One rule he seemed to have forgotten early is that each set can only be used once in each box, row, and column, so when he found the box without a 1, he knew all other boxes have a one since there is only one of the 11 sets that has no one.

[@constanza1648]

And once you know there is one box without a 1, there must be one col and one row without it.

[@studgerbil9081]

Simon refuses to use the cheat sheet to help out. I used it shamelessly and it really helped.

[@ReaGool09]

Wow! I did not expect this to be one of the few puzzles that I can actually solve without Simon's help. Granted, it did take me 5 hours. And I could never have solved this without doing the math first to find the possible sets. EDIT: Now that I'm watching Simon solve the puzzle, I've realized that I chose to note which numbers were missing and which letters were not missing for each C/R/B in my notes, whereas he's chosen to note only which ones are missing in his notes (not counting what he marks in the actual cells). I didn't even realize that I used mismatched notation in this way, but I found it very helpful, as it is easier to determine that A or B must appear than it is to determine that they don't.

[@Coyotek4]

1:19:34 (over 2 sessions) ... I'm as blown away by the solution as I am by the beautiful symmetry I note regarding the final solution. In particular ... . . . ... I count 11 possible combinations of three different digits from 0 to B that sum to 21 (not including "0AB", of course). Of those, the combos of "29A" and "678" are never missing in their entirety in any row, column, or box. Every other combination appears exactly once in each row, column, and box. Also, if you pair each row and column with the same combination of numbers, their intersection lies in a box with the same combination of numbers as both. (Alas, it is NOT the case that those 9 cells contain 9 different digits, nor does their sum equal 45.) All in all, just superb. I greatly enjoyed this solve! Wonderful puzzle!

[@PassionPopsicle]

"Being deemed bogus, lame, square etc" 😂 Have only just read through the rules, but will have to watch this for sure! (especially since it seems tailored to Simon, mentioning The Secret and all) ❤

[@jonhansen9622]

Not using sudoku is Simon's specialty! This should be a quick solve from him! Kidding, of course

[@travisdudley4520]

The plasticity of Simon's brain is a marvelous thing to watch. His ability to absorb a wildly variant rule set and just go with it on camera is astounding.

[@valentinspasov5712]

Thank you for not making all the 0s dark green. It was going to be really annoying if we had everything nice and symmetric.

[@jameswilliams4985]

SPOILERS AHEAD. I'd be interested to know if this is provable as a rule, or if it's just the way the puzzle's been constructed: -R1 is missing 38A. C2 is missing 38A. Box 1, where they intersect, is missing 38A. -R2 is missing 489. C7 is missing 489. Box 3, where they intersect, is missing 489. -R3 is missing 28B. C6 is missing 28B. Box 2, where they intersect, is missing 28B. And so on throughout the puzzle: every box is at the intersection of a column and a row that are each missing the same three digits as that box. Clearly that can't be a coincidence, but I'm not sure if it's by design or inevitable. Should say that I haven't watched the solve yet, so apologies if Simon has covered this already.

[@roccobuck3611]

Not just the intersection, but in the row and column that 0 sits on, for each box. (Edit: the 0 in R4, C1 disproves this)

[@Mounteban]

It is provable with pigeonhole principle as long as the 9 missing digits are not {3456789AB}. Here is the proof: Without loss of generality, consider 3 boxes and their corresponding 3 rows. There must be at least one repeated digit X when looking at the 9 missing digits. Otherwise, if all 9 digits are unique, their sum would be less than 3+4+...+B = 63. For each digit in the set of missing digits, it must be shared by at least one (row, box) pair. Because X is missing in multiple rows and multiple boxes, it must be shared by at least two (row, box) pairs per row. Therefore, the total number of pairs is at least 1*7 + 2*2 = 11, so there must be at least one row that has at least 4 pairs by pigeonhole principle. Looking at this row, again by pigeonhole principle, there exists a box that has at least 2 pairs in common with this row, so that box has at least 2 common digits with the row. Because the sum of missing digits is 21, having at least 2 common digits is equivalent to 3 common digits, so at least one box must share 3 digits in common with one if its rows. Looking at the remaining 2 boxes/rows, again by pigeonhole principle one must have at least 2 common digits because the number of common pairs is at least 6, so the property holds. If the set of missing digits is {3456789AB}, then the property does not always hold. There are two ways to arrange the digits: 37B/489/56A or 38A/46B/579.

[@jameswilliams4985]

@@Mounteban Brilliant, thank you.

[@jetranger57b]

I think it's provable in this way- if digit X is missing in box 1, then there can at most be 8 other instances of digit X in the puzzle, which means it's definitely missing from one row and one column. If you look at boxes 1, 2, and 3 as a whole, which comprise the top 3 rows, there can at most be two instances of digit X (one in box 2 and one in box 3) - therefore the row that is missing digit X must intersect box 1 in one of those top three rows. The same logic applies to the columns in boxes 1, 4, and 7.

[@grantfraser5430]

I'm pretty sure it's more than coincidence. Provable? Maybe some other day, my tiny brain feels like somebody is about to pull the pin.

[@chocolateboy300]

I finished in 76:04 minutes. This has been one of the most colorful puzzles I have done. The ruleset is so cool to figure out. I think my official guess for the bonus is 11 different sets, three from the AB set, and four each from A and B. I ended up using a color strategy of rows getting cells colored, columns getting a line color, and the boxes getting a perimeter line color. That really helped distinguish it in my mind. I has so much fun with this puzzle. It is a brilliant execution of an insane ruleset. This has to be one of my favorites. Great Puzzle!

[@sibelimamoglu8648]

56:49 That's 3 in the corner That's 3 in the spot-light Losing my sudoku Trying to keep up with you And I don't know if I can do it Oh no I've pencil marked too much I haven't pencil marked enough

[@micheleguerra3091]

Personally, I was finding it easier to think it this way: out of the 12 available numbers (0,1,...,9,A,B), for each line, row and box you have to remove 3 that sum to 21. I think this is easier than trying to think of all the options if just A is missing etc. Very nice video and puzzle! :) I wish I had tried it out myself, I'm curious to know if I would have been able to solve it on my own ^^

[@punksterbass]

As a composer and fan of sudoku, this puzzle is doubly interesting to me, because the digits 0-9, plus A and B standing in for 10 and 11 are the basis of a twelve tone row. So this sudoku could be viewed as a twelve tone structure of some kind and be applied to music!

[@emilywilliams3237]

The length of this video made me get out the popcorn immediately, but a sudoku puzzle where sudoku is not helpful seems so made for Simon, I think it was fantastic! I enjoyed the video, I enjoyed your enthusiasm, Simon, and the solve was amazing. Thanks for the movie!

[@pirukiddingme1908]

I just punched the air in celebration when I saw the 3 in the corner. What a sad existence I have that some confetti and a song has made my night 😂

[@JohnRichardsII]

It was such a joy to watch this sudoku solved. At first, I thought note-taking was unnecessary, but once it started being used, it became clear that it was essential.

[@katiekawaii]

Wow, I LOVED that puzzle. That was really challenging, but the deductions were so satisfying to make that I never got bored, even during looong stretches of thinking without getting to fill anything in. I'm so impressed (with the setter for constructing it, and with myself for solving it 😅).

[@janTasita]

I saw the video was over an hour, and thought I wouldn't have time to try the puzzle myself, so I started watching Simon's solve. About 10 minutes in, I'd been getting each little deduction before Simon did, so I thought "maybe this suits the way my brain works and I should have a go"... it ended up taking me two and a half hours even knowing how to get started, but I enjoyed every minute of it! (Well, apart from the point where I made a very silly mistake that took a long time to spot...)

[@Waggles1123]

This was really fun. What I used the outer grid for: There are 3 conditions: 1. The row/column/box is missing an A. 2. The row/column/box is missing a B. 3. The row/column/box is missing a set of 3 digits from 4-9 So in the first cell adjacent to each row, I tracked all of the combinations that worked with a missing A, in the second cell I tracked all that could work with a missing B, and in the third cell I tracked all of the non-letter sets. So after row 1, for example, I had (23456789A), (12346789B), and (456789). Then, I trimmed down each set, so for row 1, it trimmed down to (2389A), (123789B), and (678). After reducing for row 2, I had ( ), (19B), (489) After reducing for row 3, I had (2389A), (123789B), (678) After reducing for row 4, I had ( ), ( ), (456789) and so on, also doing similar for the columns. If you do that for each row and each column, then go along with some deductions as a result of that, you eventually start to get "x-wings" of missing digit sets in rows/columns/boxes, and you can then say that other rows/columns/boxes can't be missing those sets of digits. It's tricky to explain, but it helped me get through the puzzle pretty systematically.

[@Al-lh2oo]

"A naked single of outrageous proportions" ? Should I look away?

[@MeriaDuck]

Alternative title: the Sudoku with twenty six givens 😂 (If I've counted them correctly)

[@alvoi4379]

well, if you count A and B as double-digit numbers, they are even 29 😂

[@longwaytotipperary]

Note to Maddie- take Simon up on making a video with him!!! Note to Max - ramp up the icing!! Nothing says lovin’ like lots and lots of chocolate icing!!! 😋

[@davidrattner9]

Couldn't agree with you more my friend !! Absolutely without a doubt Maddie solve a puzzle with Simon . Yum, yum with chocolate icing..and lots of it

[@longwaytotipperary]

@davidrattner9 I want to see someone work with Simon on video and imagine it’s me!!! 😁 Yes!! Lots of chocolate icing!! ❤️

[@Grayhome]

27:56 Woah woah woah, I thought this was a family friendly channel.

[@MrBlbll]

Lovely logic bases, would love more "negative sudoku" puzzles with grayside exclusions

[@FredoPlaysMc]

This one took me almost 2 hours but all I can say is I absolutely loved it. I think what helped me a lot was writing out all of the 9 digit combinations of the digits 0 through B where the sum of the digits was 45, there are only 12 of them as far as I am aware so it was handy to have that as a reference - it made some of the finding of correct digits to place slightly easier

[@ThePoxun]

I'd love to see you solve some hexadecimal (16x16) puzzles.

[@grantfraser5430]

Mad? Brilliant? I would like to add insane to the adjectives describing this puzzle. I seriously can't believe I was able to solve without Simon's help. From the giggling comment of Mikal, I think I'll watch Simon for a bit. I don't see why I should be the only one to have suffered mental duress.

[@ansel569]

i solved this by making a table of all the possible sets, color coding them, and deducing which ones could go where. ended up being a very fun and colorful puzzle!

[@reubenmckay]

Definitely one to break your brain. Well done, Simon, on making it through this one!

[@mcstruthers]

Once I started using the note space more effectively and thinking of each row or column as 12 long rather than 9, and using more pencil marking than Simon is comfortable with, it got a lot easier. Finished in 71:41.

[@tomsterbg8130]

It took him just 16 minutes to get to something i took more like an hour to do with the aid of technology, talking about figuring out the combinations, this man is way better at thinking than we often give him credit for! Even with extensive writing down i still made a mistake with clean-ish notation where colors reflect each group of 3 missing digits. However i think if you had written it down with all the combinations and all the numbers excluded per combination like i did, it would have saved you a whole lot of time even though it's impressive how you do it with the little writing down that you did.

[@jaeusa160]

The secret of Zero-Elevendoku is that every row, column, and box of the grid adds the numbers 0-11 to total 66 BUT each row, column, and box is missing exactly 3 values adding up to exactly 21. ;p

[@bethbromley9590]

3 hours plus for this one...I mean it's as slow as I get and still have a chance of solving it! Perfectly pushing my limits!

[@ChappersDave]

If anyone sees a mushroom cloud in the vicinity of Northamptonshire don't worry it is just my brain exploding from trying to work out the valid sets of 9 numbers from 12 that sum to 45. (After reading the rules not having watched the full solve)

[@jameswilliams4985]

If you want a tip: work out the possible combinations of missing digits instead. If you don't want a tip, stop reading two sentences ago.

[@MasterOkojo]

I like that this is a puzzle that both takes Simon over an hour and doesn't take him almost that long to get the first digit in the grid.

[@wokkawicca]

2:03, I'm always slow but this one was never a drag. Marking L for letters and N for numbers helped, also noting the "1-letter only" boxes. I made far more use of the house uniqueness constraint than I expected to!

[@roccov3614]

Because there is only one combination that doesn't include a 1, once you found the box that doesn't have the 1 then you know that all other boxes have 1's. Also, I realized that any rows or columns that don't include a 1 must intersect that box. In fact, that row and column must.

[@HunterJE]

One thing eliminating 8s from box 1 gets you is it means the box must have a 5*, which can be pencil marked down to two possible places given all the 5s looking at the box *There being no way to make 10 or 11 in two different digits or 21 in three that includes both an 8 and a 5

[@jonathanallan5007]

Ahh, the unacknowledged knowledge bomb: "Five is definitely a digit" (@50:05)

[@LithmusEarth]

35 Minutes in, this is fascinating. I'm really enjoying Simon's task at hand here, and his struggle to overcome it is admirable.

[@LithmusEarth]

Solve another one of these, it really was a climb to re-wire. Just have to add in something like white dots or black dots to make it slightly new.

[@Stylpe]

I do want to make another one that toys with the norms, like a two cell killer cage that sums to 2 or 18, or just the thought of the shenanigans you have to deal with on a German whispers line...

[@LithmusEarth]

@@Stylpe I should hope you manage the task, best of luck to you sir. Your craftsmanship was a pleasure to watch.

[@cartoonkitteh]

This puzzle is beyond my skills, but I thought I'd give it a go. As expected, after two hours I got to the end, it turned out I had made an error along the way, so I admitted defeat. I'm still glad I gave it a parker try, because my brain is now thoroughly exercised and perhaps I'll be more lenient with Simon as he goes through this brain melting experience

[@st0rmforce]

I love puzzles that really mess with your brain. This is amazing

[@danagritz]

I've never attempted any of these, but I'm tempted to try this one. I feel like it would be best to start with a list of all the possible combinations, and start ruling them out for each row, column, and box. Hmm

[@haniapopowska8966]

Ahhh, finally a puzzle wild enough that Simon's comments reflect ours when we do any puzzle at all 😂

[@sam_c95]

I think this is the longest solve I've ever had, I did it spread over 3 days! I'm a little relieved to see Simon finding it hard even if he does complete it in 84 minutes haha

[@longwaytotipperary]

What strange ruleset! Getting my snacks together to relax and enjoy! 🙂

[@idraweasythings]

This one goes to 11 ❌ This ZERO goes to 11 ✅

[@penningmeestercgkdelft9159]

When having a go at this puzzle, I often made the mistake that I would take A=11 instead of A=10... And of course, that's because the Ace is often worth 11 in card games 🙂

[@davidrattner9]

What an incredible ruleset and loved the laughter and giggling!! Superb puzzle to be featured.

[@therealedvaize]

There's a nice side effect that I can't seem to really be able to explain generally but I am quite sure it is true. Every set of digits that is included in the puzzle, has a row, box and a coloumn, and what's more, they all have to cross each other. So there was never a possibility for a set to be in a row but not the coloumn or the box, or for example if box 2 was one set, the same set would have to be in either row 1,2 or 3, and in either coloumn 4,5 or 6. I'm sure there is a way to put this into words in a general term but I can't seem to do it. For me it was very visual since I cracked the puzzle a bit differently although with similar logic to simon. I decided to colour each unique set a unique colour taking full advantage of the different colour wheels and then I coloured each box, row, and coloumn completely with that colour. It made it quite pretty and showed clearly the cells in which each colour had its intersecting point (where the row, coloumn and box meet and are of the same set, or colour) Incredible puzzle!

[@Sternentier]

I love how Simon can instantly calculate in his head the digits you'd have to substitute out to get to 45, yet he is convinced that he can't think of all the ways of making 45 with 0-11. I don't know, I'm autistic, so maybe I have an advantage here. I just find it weird.

[@MrPataraga]

Absolutely Splendid puzzle, usually I don't attempt the 5/5 difficulty puzzles, but rather enjoy watching them. However the combinatorics problem this posed tickled my fancy. I look forward to watching you absolutely smoke my time of 4 hours and 3 minutes. But absolutely phenomenal logic puzzle, the setter was brilliant

[@brspies]

A really fun puzzle though I've made a mistake partway through and can't trace it back. Now to watch Simon and see where I've gone wrong. Still, fun testament to the power of THE SECRET as a constraint, really creative.

[@NettoTakashi]

I managed to solve this in... a comparable time to Simon's, and am now 2/3 of the way through watching Simon's solve, and I only just now realized... I never used the rule that no two rows, no two columns, and no two boxes can use the same set of digits! I wonder how much less difficult the puzzle would have been if I'd remembered that rule was in play?

[@LornaM2304]

I was hoping for a B in the corner! I guess I'll settle with a 3 though

[@laurabailey7430]

Embrace the pencil marks, Simon. BE the pencil marks!

[@LornaM2304]

This is too much maths for my puny brain so I'll sit back and let Simon figure it out for me 😅

[@longwaytotipperary]

Ditto!

[@minamagdy4126]

Welcome to What Might Simon Miss, where I state a mid-puzzle deduction, then we see whether Simon finds a more convoluted way of solving the puzzle. Check my reply to see whether he uses it or not. Today, Simon might miss (spoilers, obvs): At 50:15, when Simon marks column 3, that box 4 cannot have the 4 in that column. Otherwise, the digits excluded from it wouldn't add up to 21. This then automatically gives r8c3 as a 4.

[@minamagdy4126]

Simon did get the 4 in r8c3, but by logic in column 1 instead (which he did need to get other digits anyways). For full transparency, I had this in the back of my mind for longer in the video, but only when Simon got that cell did I decide to make today's comment, so I cheated to get a minor win, in a way.

[@donaldkrug]

What a great workout! I got stuck for a while because I forgot about the uniqueness rule

[@amoriamer8507]

finally, normal sudoku rules don't apply

[@MattOGormanSmith]

I have considered trying to devise a 16x16 hexadecimal sudoko, but the thought gave me too many flashbacks to the 1980s

[@bluerizlagirl]

If you use the A for 10, you have to bring in the 0 as well and cast out 2 digits that sum to 10. (4 ways) If you use the B for 11, you have to bring in the 0 as well and cast out 2 digits that sum to 11. (4 ways, 8 ways total) And if you use both A and B for 21, you have to bring in the 0 and cast out 3 digits that sun to 21 (3 ways, 11 ways total).

[@bryanroland9402]

The n Choose k Formula is: C (n , k) = n! / [ (n-k)! k! ] 12 choose 9 is 220 and that's the total number of different ways to select 9 numbers from a choice of 12 without the requirement that they add up to 45.

[@joonaskoski7998]

"5 is definitely a digit" oh the knowledge bombs

[@SwordQuake2]

Should've listed the possible sets in the notes cells

[@MarushiaDark316]

My initial guess for "how many valid combinations exist" was 54. In combinatorics, "11 choose 9" would be 11 * 10 * 9! / 2 * 9! (where 9! = "nine factorial", i.e. 9 * 8 * 7 ... * 2 * 1), which equals 55. This is because you're given 11 digits and each set uses 9 of them. This is equivalent to "11 choose 2" if you select the two you're getting rid of. And then we take 1 set away since we're not allowed to use vanilla 1-9, which leaves 54. However, I forgot to include 0, so that would then be "12 choose 9" which is 12 * 11 * 10 * 9! / 3 * 2 * 9! = 220. Take 1 away, that leaves 219. However ... that ignores the fact that the sum must still equal 45 in all cases. So then we have to add the digits 0-11 (which is 66). Subtract from that 45, leaving 21. So the three remaining digits have to add to 21 and then it's a matter of how many such combinations exist. If we remove 11, then it's how many 2-cell combinations add to 10. So you have 1-9, 2-8, 3-7, 4-6 (so 4 total). And if you remove 10, how many add to 11? So you have 2-9, 3-8, 4-7, 5-6 (so 4 again). You can't take out 0-11 or 0-10 cuz then you're left with 1-to-9, which is invalid. Add the three ways of making 21 with three digits (9-8-4, 9-7-5, 98-7-6) and the total is 11 possible ways.

[@Kairamek]

Maddie, please, for all of us, make the video. We all yell at the screen when Simon misses the obvious. You have a chance to be heard!

[@janerobson2297]

44:10 Why did Simon deduce that R5C46 are not 0? Or did he forget that there are two shades of green? Worried that he'll use that inference erroneously later

[@jackos5d851]

Arghhh! How great would it have been to have been the 11th person to solve this though?

[@RoderickEtheria]

Every set of removed digits included in this puzzle match exactly to one row, one column, and one box of the sudoku. No options that were available were used for only one or two houses. If they were used at all, they were used 3 times.

[@spreekstem]

I now understand how Alice must have felt after following the white rabbit 😅

[@doooooomed]

I usually really enjoy following the logic as Simon works puzzles out but I cant keep up with all the mental arithmetic in this one.

[@LexiPopuli]

Amazing puzzle, Simon's solve is just as amazing! Cracking stuff!

[@shaunelliott8583]

I haven't checked the stats but I feel like this puzzle is equal parts brilliant and rotten

[@Stylpe]

Thanks, as the author of the puzzle, I'm inclined to agree 😼

[@stephenbeck7222]

1:13:00 That’s no, ahh, ooh, yes, oh, no dear, dear, dear, oh that’s great!

[@Kinada]

I broke this right at the end. Thankfully I was able to spot where I went wrong and back up and reevaluate, but man that took a really long time to get through. Cool idea though.

[@Mujaki]

Makes a yellow aide-memoire. Forgets to log deductions into it. Siiiiiiiigh...

[@haraldlonn898]

Simon, have you done a hexaduko. Love your videos, all of them. Including Mark, he is a soo great solver. Thanks.

[@penningmeestercgkdelft9159]

Hexaduko or hexadoku? ;-)

[@haraldlonn898]

@penningmeestercgkdelft9159 dyxlexik

[@alanclarke4646]

Wow! Took me a looong time but very enjoyable 😊

[@effiebriest1278]

N hours later... Omg, i actually solved it, almost without checking some arrangements with Simon.😉 Great fun!

[@stephennichol3620]

I think if you filled out the notes you would have gotten so much faster. A few times you said this row cant contain a B or A and if you put that in the note the next steps were so much easier to see

[@thegreenmageli]

was wondering if it is correct to conjecture that there is a correlation between the missing sets to each box and its respective rows and columns for example to be clear C1 C2 and C3 are 56A 38A and 19B but they exist in box 1 4 and 9. Also if this is true would this be a helpful tool or just something that happens to be weird and awesome?

[@Stylpe]

Yes, another comment has a proof and an exception for this! kzbin.info/www/bejne/bKW8fmV5odKdjNE&lc=UgwyPNUm_cd0Ygm7p0J4AaABAg.ABHQzdnRJSbABI-YTC6VLw

[@MarkBennet10001]

Interesting puzzle - will be fascinated to see what transpires

[@MarkBennet10001]

Another way of thinking about the arithmetic: the digits 0-11 sum to 66, so each row column and box is missing three that sum to 21.

[@MarkBennet10001]

And that came out quite quickly.

[@constanza1648]

Nice puzzle, but too much to keep track in my pour brain! Even with the help or all the squares in the puzzle AND one pencil an paper to eliminate possible options for rows and colums, I end up having a couple of mistakes that almost make me give up. After yesterday fiasco with Mark's puzzle, I need a nice puzzle to come back!!

[@A_CC_K]

After a long day, A long video is just what is needed. Can we please have the secret t-shirt design on s jumper.

[@Paolo_De_Leva]

This was extremely *alien logic❗* Hence, powerfully fascinating. However, somehow it was not very difficult to grasp. It was only time consuming to perform it, because it required testing the *11* possible configurations in each row, column and box.

[@bait6652]

Curious how many solutions exist without the unique/distinct RCB constraint. So far found 1 and eliminate bunch...one branch left. Would be interesting if there was only 2 soltuions

[@xerodeus2337]

02:39:27 - I really enjoyed this solve despite how long it took me, I'm very curious to see if I took the long way around to solve this (I suspect I did) I almost gave up, and then I gave it one last shot to see if I could figure out what possible options there could be for each column/row/box - given there are only a finite amount of ways to configure 9 digits to equal 45, and it turns out, some columns only had 2 options they could be, and that clashed with other rows, and then I chipped away at the solve. Curious how Simon did it given he did it in an hour lol

[@jeremyandannadamiano4987]

I would LOVE to make a video with you Simon. Sadly I got very stuck on solving ☹️

[@Ardalambdion]

I notice the view count and see that Simon has far greater than Mark. What are the reasons behind it?

[@jonhansen9622]

@@Ardalambdion Simon does a more thorough job of explaining step-by-step his thinking when he solves, so I suspect that many viewers like that style when they are trying to learn these variant sudoku rules.

[@patriciahiddings3273]

I love Simons voice, it has a special quality that helps me to calm down and fall asleep. Maybe I'm not the only one :)

[@gi0nbecell]

I can only speak for myself, but I tend to watch Simon’s videos regularly but Mark’s only occasionally (and mostly for very specific puzzles). The reasons are that I like Simon’s style, not only for solving but also his way to communicate and that Mark frankly terrifies me a bit. Simon is an accomplished solver in his own right, but Mark’s brain is built differently. Also, with Simon I have the feeling that I can learn something about solving techniques whereas Mark jumps regularly to conclusions that are simply beyond me. I just can connect more with Mr Anthony than Mr Goodliffe…

[@Dazreil]

I find Simon more entertaining as well. I enjoy all his little eccentricities and saying.

[@LillaJag]

And also that the time is better for europeens. Mark post his video later and many europeens is sleeping by then. For me it's that I like Simon better because of the sound and his way to solve. But I have recently trying to watch Mark because I like his way to solve also, no fuss, solve it quickly and that he see for small things Simon is missing because he tends to see the difficult way rather then the easy way which Mark does. So I have started to watch Mark also.

[@shellmichael9665]

Two zeroes didn’t get their dark green shading and now I’m sad.