Is This Killer Sudoku Brutal? (Or Should Simon Hang His Head?)

[@celery6397]

Wow that was a long one! The puzzle certainly isnt easy so well done Simon! The puzzle was about juggling the low digits, and the puzzle is easier to manage with using the killer calculator (in the app) which i applaud the channel for never using so the length of the video is indicative to Simon trying to calculate, manage low digits and find out where they can and cannot go which he did a great job of! The puzzle was so tightly packed that it took an age to set and it was hard to keep on top of which digits go where even when self-solving. It was obviously more densely populated originally but i shaved it down to this layout but at an increased difficulty. I've been out the scene for a short while so im glad to be back and i hope the puzzle was fun :) - Celery

[@flwi]

Great puzzle! I didn't try it myself, but enjoy watching the solves on the channel. I wonder how you set a puzzle like that and make sure it has only one valid solution. Do you use some software to check that? I'm also blown away by the sudokupad app. It is very well done and til about the killer-calculator.

[@smet145]

Great puzzle, Celery. It's always interesting to hear the setter's thoughts. I'm always pleased when I find them in the comments 😃

[@anaayoung9142]

I used your comment as a hint and try myself with the killer calculator and I did it! Thanks for the amazing puzzle!!

[@longwaytotipperary]

@@smet145same!!

[@longwaytotipperary]

Completed my Saturday activities, got my snacks, my comfy chair and favorite “throw” (blankety thing for staying warm in your cozy chair). Ready for Simon to get cracking! 😊

[@inf0phreak]

One hour for Simon to get the first digit in a regular killer?! Yeah, this one is not for me.

[@psymar]

I got the first digit in 12:19... and the second somewhere after the 80 minute mark. Pretty quick solve after that though!

[@robinbrown6530]

@@psymar This was my experience too. I started with "Where in the puzzle can there NOT be a 1?" and it lead me quite quickly to the first digit. Then I spent an ungodly amount of time juggling low digits to try and figure out the rest of the puzzle.

[@zealot2147]

Same I gave up after 90 min after getting the 1 in 14 lol

[@RyanMcLeanau]

I’m the opposite. Love these ones

[@delaneymayo6351]

Everytime he said sorry I was shocked....sir there is nothing to be sorry about, I can barley keep up with your addition 😂 loving a longer video! congrats Simon!!

[@shadowofaman69]

I can solve your basic level local newspaper sudokus. This is absolutely next level and is so much fun watching the logic happen in real time. Amazing.

[@trace_tomorrow]

I learn so much about solving by watching your videos. Both the ones that you manage to solve quickly and the ones that stump you for a while. Normalizing the fact that it doesn’t always work easily and quickly does more for this community than a thousand secrets. Cheers on the great solve, Simon.

[@user-fp6dt1os1l]

I think a ctc video has never gone so far over my head. But it seems wonderful

[@shanem7573]

Please stop beating yourself up about your time spent on a puzzle. While it may be an hour for you, we have fast forward! Love to watch you wrestle with the logic of each puzzle, its very enlightening. 🤔

[@DitDede]

True. Simon is very consistent in providing reflections at the end of his solutions. Very commendable indeed.

[@markp7262]

1:06:19 finish. Part of my logic for the break-in was to play "either-or" with all of the cages that had to contain 1s. Basically I asked, for the cages that spanned boxes A & B, "if 1 is in the cage in box A, where does 1 go in box B?" Then I reversed it. This gave some me virtual X wings, and fairly quickly allowed me to place Simon's first digit. I then did the same with the other low digits (including 4), and was able to slowly pick it apart. This was an absolute beast of a puzzle, but very fun! --- FURTHER EXPLANATION BELOW: --- --- --- --- There must be 1s in the 13/17/18 cages. Looking at columns 7-9, consider the placement of the 1s in the 13/17 cages. Either the 1 in the 17 cage is in box 6, placing a 1 in r7c7, or the 1 is in box 9, placing a 1 in r5c7 or r6c7. Using the same logic going across rows 1-3, the 1 in row 3 must be in column 1-5, and the same logic applies for the 1 in row 4, in columns 1-5. This places the 1 in box 8 in column 6, outside of the 9 cage. The 9 cage is 2-3-4. Using Simon's logic about low digits in the cages, there must be a 1 in the 14 cage in box 7, in row 8. This places the 1 in r9c6.

[@jonathancard4466]

What I found interesting was Simon's reflection at the end of the game. That's an important step in learning that is so easy to forget to do because we're always under time pressure, but it's important to learning to give yourself processing time.

[@awilliams1701]

once you eliminated 4 from the 21 cage it was a 5/6/7 tripple with a 1/2 pair.

[@tunamonkey]

The number of times he went back to that and then didn't finish the thought killed me

[@ronjohnson6916]

Right. This is something I've observed. When he marked R6/7C7 as 123 it no longer interested him. I'm used to grinding down restricted squares and my first question was, what if 1/3. Oh impossible. Mind you I didn't get that 123 pencil mark on my own.

[@awilliams1701]

@@ronjohnson6916 lol I tend to select all and then put in candidates 1-9 and then eliminate. Especially in harder puzzles. I'm getting better at avoiding marks in easier puzzles.

[@bertbergers9171]

I read your comment worked it out to be true, and now I am seeing lot’s of moments during the video where Simon should finish his logic on that cage but uses a “discovery” to deduct things elsewhere. I know I shouldn’t read comments prior to finishing the e video 🥴

[@magnusbenzein1741]

This feels like a time when Simon would have been helped by relying more on pencilmarks!

[@abcadef6171]

I think it was mostly just hard - the only bit where I got meaningfully ahead was noticing that the 21 cage had to be 12567 straight away.

[@dontmindme2844]

I spent a lot of time looking at everything else and ignoring the bottom 21 cage as not very restrictive. After I did look at how the two 21 cages fit into it...

[@dwebb2805]

the 1 you got as your first digit was something magical. i don't think this puzzle was easy, so getting through is impressive in its own right, and i'm not sure the question "how are you supposed to see this quickly" is even appropriate for a puzzle such as this. the 21 cage did stump (or elude) you for a while, but in a puzzle this tight where you are both solving and explaining everything for a video those kinds of things can happen. thanks for the solve

[@psymar]

I got a 1 in about 12 minutes... and needed about 70 minutes after that to find the second digit

[@longwaytotipperary]

@dwebb2805 well said!!

[@davidblake6889]

You were a bit lucky with r5c6. You said you were taking 4 out of it, and promptly removed a 3 @1:37:57. It didn't impact the solve, but if I had done that, (which I do most frequently) I would be winding back to find my error. Great tenacity, Simon. It was definitely a hard puzzle, and not one I would even attempt. Kudos, my friend. It was a great journey watching you go through the logical process to find the solution. Thanks for a great video as always.

[@ezra7088]

I was wondering if anyone else noticed that

[@ServantOfSatania]

62:55 For me, the amount of cross-box pencilmarking alone makes this quite a beast to conquer

[@ShakalDraconis]

a piece of the low digit juggling that I saw once Simon started coloring in the low digits. NORMALLY, the 14 cage and 9 cage in boxes 7 and 8 COULD be made without using a 1 in either, with 2345 and 234 respectively. But in this case, that would force a 234 triple into row 9 of box 9, but we know r9c7 is at least 5. So we KNOW that 1 MUST appear in at least one of the boxes. I'm not sure how helpful that would have been to see, but wanted to share.

[@dontmindme2844]

I got that part early but couldn't turn it into anything all that useful except taking some high digits out of the boxes. I felt like I was all over the solution like Simon was and just couldn't piece it together, but I mistakenly didn't think that bottom 21 cage was very restricted so mostly ignored it.

[@WimmekeVL]

You solved it, I didn't. You win. Don't be harsh on yourself. You can now count yourself among the select few that did solve it.

[@Mephistokles333]

Dont apologize for solving a brilliant puzzle.

[@longwaytotipperary]

Completed my Saturday activities, got my snacks, my comfy chair and favorite “throw” (blankety thing for staying warm in your cozy chair). Ready for Simon to get cracking! 😊

[@myacky5887]

Nothing better!

[@longwaytotipperary]

@@myacky5887 ☺️

[@anaayoung9142]

Hi Simon, I am from South America too!! After I discover your channel I discover that we can get addicted to sudoku!! After read the creator, Celery, about this puzzle I decided to try it and I as able to do! Amazing. Of course I used the killer calculator, only like this I was able to do! But I am still happy that I was able to find the logic to do! Thanks for the solve! 🤗

[@karolis46points91]

Finished it in 41 minutes! Very surprised that something clicked for me with this puzzle, considering how much Simon struggled on it. This kinda made my day

[@inspiringsand123]

Rules: 04:43 Let's Get Cracking: 05:24 Simon's time: 1h40m39s Puzzle Solved: 1:46:03 What about this video's Top Tier Simarkisms?! The Secret: 4x (16:13, 16:18, 16:25, 16:25) Bobbins: 1x (32:34) Knowledge Bomb: 1x (23:05) Three In the Corner: 1x (1:41:07) Phistomefel: 1x (17:41) Numpty: 1x (1:40:30) And how about this video's Simarkisms?! Sorry: 25x (03:23, 08:31, 28:29, 33:23, 34:45, 38:42, 38:46, 41:13, 45:28, 48:05, 48:05, 52:42, 52:42, 52:42, 53:16, 1:02:24, 1:08:31, 1:09:01, 1:20:44, 1:23:48, 1:27:00, 1:31:29, 1:36:17, 1:48:10, 1:48:27) Ah: 8x (27:22, 43:20, 47:55, 1:23:22, 1:29:58, 1:32:41, 1:35:57, 1:37:22) Hang On: 7x (19:49, 29:52, 44:43, 1:06:42, 1:31:51, 1:35:20, 1:36:44) Wow: 7x (07:23, 56:31, 1:00:54, 1:04:57, 1:33:05, 1:37:26, 1:46:08) The Answer is: 5x (35:31, 38:17, 43:08, 54:43, 59:33) Cake!: 5x (02:15, 02:48, 02:48, 02:51, 02:51, 02:59, 02:59, 04:16) Good Grief: 4x (1:31:08, 1:36:35, 1:45:52) Goodness: 4x (49:25, 54:32, 57:30, 57:51) Brilliant: 4x (1:06:04, 1:06:07, 1:48:40, 1:48:40) In Fact: 4x (21:54, 1:22:35, 1:42:13, 1:42:18) Weird: 4x (30:07, 39:26, 44:40, 54:32) Stuck: 3x (17:24, 1:18:47, 1:18:49) Obviously: 3x (45:40, 59:53, 1:48:10) Nature: 3x (1:09:14, 1:12:25, 1:13:05) Pencil Mark/mark: 3x (10:15, 50:17, 1:27:28) What on Earth: 2x (26:07, 42:06) Bother: 2x (38:46, 1:03:49) Nonsense: 2x (08:28, 26:32) Naughty: 2x (05:18, 31:24) I Have no Clue: 2x (43:10, 1:16:48) Beautiful: 2x (1:49:08, 1:49:08) Fascinating: 2x (39:23, 54:35) Incredible: 2x (02:08, 57:30) By Sudoku: 2x (12:43, 21:39) Naked Single: 1x (1:45:26) Ridiculous: 1x (1:31:42) Going Mad: 1x (1:02:06) Hypothecate: 1x (36:12) Shouting: 1x (1:31:33) Of All Things: 1x (1:44:23) Surely: 1x (1:03:16) Which Means What?: 1x (1:30:16) Phone is Buzzing: 1x (32:19) Almost Interesting: 1x (1:26:06) Baffling: 1x (47:42) What Does This Mean?: 1x (1:33:48) Triangular Number: 1x (13:00) Most popular number(>9), digit and colour this video: Fourteen (43 mentions) One (195 mentions) Purple (45 mentions) Antithesis Battles: Low (89) - High (28) Even (5) - Odd (0) Row (25) - Column (18) 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!

[@alexandradunspaugh162]

🍪🍪🍪 good job little bot 🍪🍪🍪

[@TehFilmFanatic]

This was a tricky one that took me about an hour. This puzzle feels designed for case-testing, which isn't Simon's usual style. I wonder how long Mark would take with this, as he turns to that strategy pretty quickly

[@WimmekeVL]

I did solve some sudoku's on paper in the car while it was charging. It's the perfect way to pass the time, but no computer solving there.

[@michaelmatter1222]

Bravo 👏👏👏 (to Celery & Simon 🙂)

[@michavolmar]

Makes me so happy to watch your videos. It really brings peace to watch and I love that I came across the channel by accident some time ago.

[@orliag218]

I screamed about 21 box for half an hour. But to be fair, i played a lot with boxes, and remember most combinatons, so as that the 21 box with 5 nums, no fours and 2 low nums can have only 1 comb. Btw, great video and great puzzle

[@LadyEmilyNyx]

Stared at this for 40 minutes before giving up. Happy to see it wasn't something simple I missed.

[@lhesitante]

Impressive solve, Simon! One hour in, my phone rang and I went to another room to talk. I forgot to pause the video and was mighty confused half an hour later when there were still only two digits on the board.

[@laurv8370]

It took me 1 hour, 49 minutes and 29 seconds to watch Simon solving this. And it was quite easy to follow 😜

[@zirco77]

Glad that Simon got the "right question to ask" at about 58:00... kids were in bed already, I had to keep myself for shouting for half an hour 😅 That's definitely a nice break-in! Took me a while too to figure out where were all those 1s putting pressure on.

[@JalebJay]

44:42 Something felt right about the cages. I'm interested to see what got Simon stuck.

[@JalebJay]

Amazing that I found 1:00:15 within 5 minutes. Really shows how the thinking will solve a puzzle quickly.

[@Li3Kung4]

At 1:06 he puts 567 in the 21 box and I'm just waiting for him to put those in the rest of the box. 5+6+7=18 so it is a 1,2 and purple is 3. This would have probably cracked it for Simon.

[@psiphiorg]

Even on the long solves, I usually try to give it a go first. I struggled for so long and couldn't find a path forward, Even resorting to bifurcation (e.g. "What if there's a 1 here? What does that do to the puzzle? Okay, now what if 1 is there instead?") had very limited results. So I decided this one was too advanced for me... and after watching Simon's solve, I think I was correct in my assessment.

[@tntblender6802]

I love the thumbnail for this video so much. You are absolutely losing it to the boxes.

[@AchintanDey]

Brilliant solve of a very difficult but fair puzzle. Good to see Simon not get flustered and tense despite being stuck at various points

[@AndreasKungl]

Simon: Don't be sorry for the length of the solve. In fact, I certainly can relate very much to your struggle, as it is my MO in many a puzzle that you guys normaly breeze through. Thus, I envy your stamina and tenacity, which I oftentimes wouldn't be able to muster.

[@frankjiang1857]

Finished in 52:07. Not brutal, but certainly not easy. I've got a ready command of killer cages from doing so many, but it still took me a while to figure out to focus on where the lower numbers could be from the cages. My break-in was penciling in all the possibilities of where 1 couldn't be and realizing that box 8 had a specific place for 1. That lead to box 7 being solved by comparing what happens with various possibilities and where that lead for the cages in boxes 3, 6 and 9. After solving for those cages, it was rather trivial to figure out the rest of the sudoku as everything flowed from there. Fun puzzle!

[@bobber0001]

Thanks for the super video Simon!

[@xerodeus2337]

by the way Simon you didn't disappoint anyone, we love hearing how your mind works

[@brianmcadam443]

This puzzle felt like having a word stuck on "the tip of your tongue". Only it *stayed there* for over an hour. I could see the strategy, I knew what I was supposed to be finding, but I just couldn't quite get to the finish line. 88 minutes and change to finally sort it. The 21 cage spanning boxes 6-8-9 was the key that finally unlocked everything, once you sufficiently reduce the options in column 7. Brilliant construction, because it's brutally hard without ever once feeling impossible. It's *right there*, but just out of reach.

[@dontmindme2844]

I felt exactly the same way. I saw the general concepts and saw the restrictions crossing the grid...and just couldn't put it all together (until realizing it was the two 21 cages that forces the pieces in place).

[@rampantunease6517]

That was hard. I got a 1 sooner then Simon but that's it several hours thinking about if that than.... But I finally got done and it feels good. Excited to see the comments and watch the video now.

[@zygmunthorodyski]

Cheat code on: "watch Simon". hardest sudoku I ever seen

[@xerodeus2337]

1 hour and 18 minutes in and Simon only has 2 digits... yeah I"m glad I gave up early on this one

[@Gonzalo_Garcia_]

23:57 for me. What a fantastic puzzle, loved it!!

[@remush_gym]

I'm just curious, when will the sudokupad get an update on steam? It's unfortunate to not be able to use stuff like pens and crosses for some sudokus.

[@derekjc777]

You can enable the pen tool in the settings (cog icon). Unfortunately the app only does green lines and symbols at moment, and no diagonal lines.

[@ariel6574]

every time i manage to notice something Simon has missed (which is NOT often), i start screaming (lovingly, obviously) at the screen and then when he notices it and apologises for missing it i always go "it's okay, don't worry!"

[@doncook4097]

The most difficult break-in. I did spot that the spot that the 21 cage didn’t have a four and just flowed from there. Thanks Simon for the break-in I don’t think I would of found it

[@4bene4]

Finished it in 22:15 I realized soon that the cage in box 7 had to include a certain digit. Made the solve way easier.

[@LeonardoBlanco-qw1fg]

You were most definitely not being dim, Simon -- this was *not* an easy puzzle. If this is four stars, I'm not sure what constitutes a five. I wasn't looking at the clock carefully enough, but it took me about 1:30 to find that first "1". Finally solved it in about 2:17. For what it's worth -- which I'm not sure is much, but I'll mention it -- I followed pretty much the exact solution path as you did, and it looked so very tight that it seems to me that was the intended path. Anyway, wonderful video as always!

[@oresthopiak8609]

Honestly, I never stop being impressed how Simon says something incredibly clever that I would not think of, and then immediately he just forgets this genious thought😂 then I am rooting for Simon to remember it, and when he does I am like "Yay🎉🎉 Finally you appreciate your own genius" The most funny thing for me is that I watch and try to do some dedictions, my head does not produce anything, and then when Simon makes a breakthrough for me, I need to wait for him to go on😂

[@asbjrnfossmo1589]

I also went along figuring where 1s couldn't go, and I noticed that there would obviously be one in box 3, but NONE in the cells adjacent to box 3. Now, that has implications for that particular set thingy, where you colour box 3 and the adjacent cells in one colour, and the adjacent to box 7 plus one more "layer". That last colouring reveals that there cannot be a 1 in the 9-cage because the only 1 is spent in the 13-cage.

[@babelwabel170]

I was so proud of my self, that I found that first one faster... but I didn't find much after that 😅😅

[@emilywilliams3237]

I have read through a few comments, and especially Celery's own is quite interesting. Low digits, indeed, as you discerned, Simon, and I also am very, very glad that you (and Mark) don't use the many fine tools that are available, such as the killer cage calculator (which Celery mentions) as well as the various levels of error checking that Sven has built into the CtC software. I also don't use those (and thus would never, ever attempt this puzzle!) and I based my choice not to use them because I wanted to be more like you and Mark! Thanks so much for your stamina and persistence in working out this puzzle and all of the logic it contains.

[@annesorensen4004]

Two hours…. 😗 That means popcorn and wine 🍷🍿 😇😁

[@smet145]

If it takes Simon two hours, I'm definitely getting out the popcorn and not the pencil!

[@longwaytotipperary]

We are on the same wavelength!!

[@finmat95]

Wine???????????

[@colemanhansen206]

Im really digging your shirt in this video Simon

[@longwaytotipperary]

No need to apologize, Simon. Even Celery praises you for your solving! And I praise you for your perseverance and overall good humor throughout!!!

[@MarushiaDark316]

It took a long time to get going; but once you finally got a digit, the rest went pretty smoothly. I think it's just monstrously hard for a killer sudoku.

[@Ardalambdion]

When I see an 80+ video here, I just refuse to solve it, put them on double speed and enjoy the show. I admire Simon for recognising patterns where for us there is none.

[@longwaytotipperary]

Agree about Simon finding patterns that are invisible to me!

[@ericpraline1302]

I doubt I would ever have spotted that deduction about 1 in column 6 but once I'd exploited Simon's massive brain ironically I probably finished the puzzle quicker than him.

[@biaberg3448]

Take a great bow everyone who has solved this puzzle! You are genius!

[@Raven-Creations]

31:27 for me. If only you'd kept on thinking about 1s at the start, you'd have found that in boxes 2 & 5 it is limited to C4/5, so it can only be C6 in box 8, making the 9 cage 234. If the 14 cage in box 7 didn't have a 1, it would contain 234, which would mean that R9 in box 9 would have to be 234, but it can't because one cell is at least 5. Therefore there is a 1 in R8 of the 14 cage, and R9C6=1. You could have got your first digit within a couple of minutes. The other cells in box 8 are 5-9. The large 21 cage now includes two cells of 5 or more, so the other three must sum to no more than 10. This means that your green digit must be in R3C8 and R4C9, and cannot therefore be in the 21 cage in box 2, which therefore must include a 7, the other 89 digit, and a 56 digit. The 14 cage in box 7 must include at least a 2 or 3, which must appear in R9 in box 9. This rules it out of the large 21 cage, which means that cage must include 1, the other 23, and a 4567 to go with the digits in box 8. Because the 13 and 17 cages both include the other 23, R6C8 cannot be 1, 2, or 3, so must be 4567, leaving R6/7C7 as 123s. The square 13 cage now must include 4, which means that 4 in C7 must be in R5C6. This rules 4 out of the 21 cage and means the 21 cage can only be 12567, making yellow 1, blue 2, and purple 3. If there is anything obvious that you were missing, it is this. Once you got the 4 in box 6, the minimum that the high digits could be is 567, leaving just 1 and 2 for the others. This means the 13 cage must be 1246, the 14 cage in box 7 must be 1346, there's a 34 pair at the bottom of box 9, so there's no 4 in the 17 cage which must be 12356. From this point, it all starts to unravel quite quickly. It was interesting to see how just that small deduction early on made the puzzle so much easier. You commented that you'd not got a digit after over an hour, whereas I got it in a couple of minutes. As I was watching your solve, I tried to put out of my mind the missing deductions, so I could see it from your perspective. Up to where you got the 1, I really couldn't see anything else that you were missing. After that, not spotting the make up of the 21 cage once you got the 4 in box 6 was baffling. Maybe if you'd pencil-marked the two cells in box 8, you'd have seen it. Even after ruling 8 out of the 21 cage, you still didn't twig that it had to be a 567 triple with 12 in C7. @ 1:39:00 - "Does that resolve our colouring?" - That was resolved ages ago. You've already put 1 in yellow in box 8, and you know blue is 2 and purple is 3. In answer to the video title, no it wasn't brutal IF you spot the opening 1, but you also don't need to hang your head. Having said that, the disposition of the 1s was clearly ratty in odour, and an experienced solver like you should have at least pushed a little harder. After that, not spotting the 21 cage's limitations was certainly something you should have easily spotted. This boils down to your old problem of not checking the effect of your placements. Had you asked what impact placing the 4 in box 6 had on the 21 cage, you should have easily spotted that minimising the high digits to 567 left just 12. @ 1:10:31 - "This 21 cage has fourteen more digits" - As Adam Savage used to say, "THERE'S your problem!"

[@Rmifaabsbb1]

The trick is to color every cell where one cant go, row 9, column 6 "1" fills in immediately

[@selinafox]

I don't drink... but after watching you go through this, I almost wanted to drink lol. If you are a drinker, you deserve one!! This was a tough one!!! 👍👍

[@qqleq]

Well that's three hours of my life I'm never getting back... 😉

[@Naib0930]

Yep, not one I would have a chance at, occasionally I can see the logic before Simon but I don't think I saw a single thing before Simon pointed it out. Nice solve, this was will beyond me.

[@marcrindermann9482]

I have to rewatch this one again (well, I say have to; get to rewatch rather 😄) because I didn't get the point why there had to be a 4 in the top right 13 box or in other words why there couldn't be a 7 in that box.

[@myfyrmadocjones]

My favourite sudoku type, though the dearth of cages makes this look really difficult

[@RoderickEtheria]

Took me a little over an hour. It is quite a beast. Lots of cross-referencing to spot.

[@zergrush8709]

63:38, I managed to find that first 1 pretty quickly so I'm glad I managed to beat simon for once

[@toms7114]

Simon got lucky when he removed 3 as a possibility from r5c6 instead of the 4 as a misclick that it turned out all right. Especially since not 30 seconds later he could legitimately eliminate the 3 by filling out the 13 cage in rows 5 and 6. Where 4 in that cage was in the sole row 6 cell, forcing a 3 into row 5 in that cage removing the 3 as a possibility from r5c6.

[@RichSmith77]

Good spot. I missed that. Luckily it didn't impact the solve path in any way. As you say, he could legitimately remove 3 as an option moments later.

[@LarkyLuna]

I'm glad I got the idea soon of trying to pinch the 21 cage from low and high so it wasn't that long of a solve, but still pretty hard The name seesaw clued me in

[@MattYDdraig]

48:18 Definitely brutal and no need for any shame on Simon's part. As is often the case it comes down to looking atnthe right place at the right time (I was fortunate enough to get the same first two digits far earlier than they were looked at in the video). I also tried using a SET trick which didn't exactly break anything open but looked like it should, but it gave me all sorts of other options when trying to rule out digits. Really good, but very tough puzzle. The SET idea, which looked promising but didn't really break things open the way I hoped was to colour two sets; Red: columns 3 and 7 Blue: boxes 3, 6 and 7 This gives blue total being 45 higher than red total via a secret I heard somewhere. Eliminating cells of both colours preserves the difference. Eliminating the 14 cages -one of each colour- preserves the difference. Use of the secret gives the remaining red in column 3 being 14 more than the remaining blue in box 7, so eliminating made the difference 59, and taking out the blue 13 cage left a difference of 46 between the one remaining red cell (r7c7) and the 8 blue cells in columns 8/9 rows 3 to 6. Noting that that red cell was repeated in those blue cells gave a sort of virtual 7-cell cage with definitely one 8/9 duplicate and possibly one other that added up to 46. Looked beautiful as the eliminations matched off but ultimately just gave me some strange alternative ways to look at the options and clearly not the intended solve. All that said, I was only even looking in ways like that because of the text under the video.

[@doych999]

Finished it in 61 minutes, one of the first times I beat Simon!

[@sanabas1]

So, I got the same first digit inside 5 minutes. I haven't watched the video yet, but if the first digit took an hour, I suspect Simon did miss a trick to make life easier. A longish explanation: Many cages need to have a 1, so I coloured them in. 18 cage is purple, box 3 13 cage is blue. Box 4 13 cage is yellow. 17 cage is green. 21 cage is red. Slightly tricky bit, the 14 & 9 cages could be 234 & 2345, but that would put 234 in r9c789, which is impossible due to the 14 cage. So there is at least one 1 across those 2 cages. 9 & 14 cages are both orange. Now I have 6 colours, and each colour has a 1. Now start turning cells that can't be 1 black. r1r2 have two 1s and two colours entirely in those rows, so rest of r1r2 is black. Rest of box 3 is black. 21 cage is black. 14 cage is black. c89 have blue + green 1s, so rest of c89, including one red cell, turn black. Now box 9's 1 is in r7, so rest of r7 turns black. Now the orange 1 is in r8, so rest of r8 turns black, including one red cell. Now r567's three 1s must be in yellow/red/green, so rest of r567 turns black. Now all of c6 is black except for r9c6, which must be 1, and the 9 cage is 234. Now the two cells of the 21 cage in box 8 are minimum sum of 11, so there is no 8 or 9 in the other three cells of the 21 cage. so the large digit in the 14 cage must be in the unnumbered cage in box 6, which means it is in r3c8 + r4c9. And from there, it's a tough but not movie-length puzzle.

[@sanabas1]

Next step was to think about 2/3 across r78 & c89. At least one of 2/3 is in the box 7 cage. It is in the 9 cage. Therefore by looking at r78, it is in r9c89. It is in the 17 cage. Therefore by looking at c89, it is NOT in the box 3 14 cage. So delete all the colouring, and start again. Colour the known large digit blue. One of 2/3 is red, the other is green. The box 7 cage has the red digit, the box 3 13 cage has the green. The 21 cage can't have a red digit, so must have a green digit. So r67c7 are a 1/green pair. Box 3's 13 cage is either 1246 or 1345, and has a 4. Therefore c7 only has one spot for 4, and the 21 cage has no 4, no red, so must have at least 567. Therefore the other two digits are 12, so green is 2, red is 3, and you can do a lot of pencil-marking. r12 have two 2s in cages,, so c6's 2 is in r56. combined with the 2 in the 17 cage and the 12 pair in the 21 cage, that's three 2s for three rows, so the box 4 cage has no 2 in it. That places another 4, and now 4 in c6 is in r12, so the 18 cage has no 4 and is 12357. The 17 cage also has no 4, and is 12356 That places a bunch of digits, makes the blue high digit an 8, and it's more or less straightforward from there. Very fun puzzle to do.

[@titusadduxas]

2:21:12 - Solver 666 😈 Again! I wouldn’t normally even attempt a puzzle that took Simon so long but Clover has always produced some excellent puzzles so I thought I’d give it a go. Once you got the break in which took me about 1.5 hours!, it started getting easier; I definitely needed the killer cages calculator though!

[@piarittersporn]

Without support I wouldn't be finished before Christmas. Nevertheless a great puzzle.

[@Wecoc1]

This puzzle was great, one of the best I've solved in a while. It took me almost two hours though 😆

[@ianagol]

I used set theory on box 6 and rows 7&8 to constrain the noncage digits in those cells (in particular they contain no 1s or 2s ). I tried to use some other set theory but it didn’t seem to work.

[@chrislewandoski3383]

My first time I ever beat a Simon time. 79:55. Cracking the 1 in box 8 not being in the 9 cage was the first big break.

[@mariutschOoO]

At 1:37:50 you assumed a quadruple in C6 R1,2,5 & 6. You marked it and concluded several seconds later that because of the 4 in C7R5 there could be no 4 in C6R5, but erased the 3 instead of the 4. I was so shocked and hoped that it won't lead you to any mistakes. But in the end you got lucky it was a 50:50 between 3 & 8 and you decided correct. 😛

[@eckberthighwater2555]

I got the 1 pretty quickly and then screeched to a halt

[@H0lyMoley]

Me (after going through this thing, pencilmarking everything, and hitting the 90-minute mark without putting in a single actual digit): "Screw it, Simon probably did it by shading the cells in a dozen colours or something." Skip to 30:00 - Simon's sudoku is now a pretty rainbow.

[@jelenaradulovic2214]

63:09 I almost gave up trying to solve it when I saw how long the video is. I'm glad I didn't. 🙃

[@mvpoker9704]

I have a massive digit in a cage

[@77kaczka77]

What a stone hard high level puzzle. Simon, please excuse me for my doubts in your genius in a middle of this video. I virtually sprinkle ashes on my head and repent before You. 😉 👍👍👍🎩

[@alienrenders]

54:36 for me. Just had to look for restrictions on the low digits. Interesting puzzle.

[@alienrenders]

Just finished watching the solve. Simon got stuck on the 21 cage for a while. But at the start, I coloured the whole grid to see where the 1s could go. I later coloured where the 2's and 3's could go. And with a bit of thinking about the square cages, it eliminated a lot of possibilities. I didn't get the first 1 the way Simon did. With the coloring, I found that 2 cells in box 8 could be 1's. The other cell was in the 21 cage on row 8. But if that was a 1, it means that the cage in box 7 was 2345. The 9 cage is 234. That means 234 has to go on row 9 of box 9. Not possible since one of the cells only allows 5689. When I saw this, I started looking at the other cages for similar patterns. That's why I colored the 2s and 3s as well and the puzzle broke open.

[@zooikis]

Oh SeeSaw. That means that you have to See Saw, that is pentomino that looks like saw. Now I get it. I would newer solved it anyways.

[@srwapo]

It's 10:00 pm, how is this video only a half hour old? Oh, I'm in Europe this week...

[@alexm495]

I enjoy the long videos, but I do tend to skip ahead when it's 2 hours long. Have you considered releasing 2 videos, one full length and one edited down? You could leave in maybe a little of the "I'm stuck here" and other entertaining commentary, but otherwise it would be "highlights" of the logical deductions along the way. Just an idea!

[@jimi02468]

"Is this killer sudoku brutal" Certainly yes, judging by the video length.

[@aliengeo]

Don't beat yourself up over taking a while. Most people would be effectively incapable of solving this in a reasonable timeframe without guidance, and the people shrugging and saying it was 50 minutes don't have to regularly film themselves with the knowledge that other people are going to see their every mistake and comment on it. The setter said you did fine and I agree.

[@LednacekZ]

46:37 for me. I am quite sure i made a mistake at the start, but got lucky. Otherwise there is no way i am so much faster than Simon.

[@shaunbrowne9870]

Well I can tell you that once you have that 1 is yellow you can rule the green digit out of the 21 cage (because I had forgotten that was merely an option rather than an established fact, made several calculations based on that assumption, and was "yelling" at you for not being able to see that 4 in box 8 *had* to be in the 21 cage and the implications thereof). I'm not deleting that just because it ended up being your next deduction; the world should see my shame. That being said, you not spotting the fact that the 5 in r6c7 ruled a 5 out of r7c7 or the 16 pair in row 3 placing a 4 directly between them *does* make me feel better about myself.

[@JohnGottschalk]

Simon saying the 21 needs a 5 & a 6, then minimising the other 2 to 1,2 and then looking at the other square and saying its a maximum of a 7, finding the 4 in the 6th box, and then moving on without marking anything x_X (1:06:00) EDIT: Skims past it at 1:18:00 again. EDIT 2: He finds it at 1:31:00 and recognises I was shouting at the screen for ages xD

[@six_5000]

Don’t worry Simon - while there MIGHT be the possibility of a better solve path, there is DEFINITELY a much stupider way to do it… eg: After a few pencil marks, I just guessed r6c8, and wildy assumed there was no 4 in the cage. Still took me 101:44

[@mtnan1950]

I knew you could do it

[@adipy8912]

1:48:35 The ones where people tell you what you missed is the type of comments you find unkind and I agree that they should stop with that. But they don't mean to be unkind, they just tell you an alternate logic. Please stop apologizing for being a human

[@iceberg54321]

27:00 You missed that the 3 had to be in the 18 cage by maths. 2 of 1,2,and three had to be in the 18 cage, so at least one blue or yellow had to be in row one. Now if you put both blue and yellow in row one, you need two digits less than six in the 13 cage in row 1. Either way, it is impossible now to make the 18 cage and 13 cage work by maths unless you include the purple digit, as if you don't have a 3 in the 18 cage, you have to place too many middly digits (at lest two for 4,5,and 6) (or all three if you put the blue or yellow in row 2), in row one in the 18 box. Which makes you put a 7 8 or 9 in row 1 in the 13 cage, which doesn't work, since you can't put a two or a three in that box. The minimum, 1,2,4 and a 7 is one too many.

[@iceberg54321]

That was the see-saw, you had to include all three low digits in the 18 cage, to make the 13 cage work.

[@RichSmith77]

Why not 12456 in the 18 cage (1 in row 2), and 1345 in the 13 cage (4,5 in row 2)? Purple digit being 2. That doesn't require a 3 in the 18 cage.

[@iceberg54321]

@@RichSmith77 Because then the 13 cage is broken, you have to put at least one 1 or 2 in row one, so you need a middly digit to go in the 13 cage. But you would be putting all three in the 18 cage. If you put the 1 and 2 in row one, you need two of 4, 5, and 6 to go into the 13 cage, so it has the same problem. You need a high digit, or the 3, to go into row 1 in the 18 cage. and it is impossible without a 3 being in the 18 cage.

[@iceberg54321]

@@RichSmith77 The other way to look at I suppose is you don't have four free spots, that are not in the 13 cage, to put the 3,7,8, and 9 in row 1 if none of them are in the 18 cage. So 1,2,4,5,6 will not work.

[@iceberg54321]

I should purple digit instead of 3 but it works out the same. if the purple digit was a 2, it already went into the 18 cage.

[@Epic-1224]

2 hrs and 27 mins for me lol

[@Huayro]

1:36:31 did i miss something or why could he say thats not a 6 ? Missreading of pencil marks maybe ?

[@RichSmith77]

The 346 triple he briefly ran the cursor over (purple) had to contain the 6 in the row.