How To Master Killer Sudoku

[@Pyromonkey83]

Great puzzle. For folks like me who struggle greatly with killer sudoku, I found some logic during my solve that I feel have great applications elsewhere, which often go missed by me as I focus too heavily on long logic chains when something might be staring me in the face. Some of these were made very obvious in this puzzle which was great for a beginner like myself. Took me about 30 minutes to solve, which I expect is very long for most killer experts, but I'm quite happy I was able to get it done without assistance. EDIT: PS - We have a Sandwich Sudoku app, and a Classic Sudoku app... Any chance we get a Killer Sudoku app in the future? :D

[@tremkl]

I don't think I've ever so appreciated when you say a puzzle has a specific solve path. I kept even with you on time for the first 6 or so minutes, but missing the trick that the 18 cage and 17 cage on the same row gave you the 3 and 6 in the center box turned the whole puzzle into an absolute slog to make progress. I knew the whole time I was solving it that you must have spotted something that made that part easier.

[@dragnl0rd]

Holy wow I solved it myself! I didnt think I would! It took 1:51:18, but I managed to solve it before watching the video! WOO! (Also, I read the comments after watching the video, since we went a different way... and I'm super hyped that I saw the same thing mentioned by Mr. Seeliger regarding the 9 cage requiring a 6.)

[@christophseeliger5551]

You could have done the same trick with the 8-cage on the left side with the 9-cage on the right side: For similar reasons, it has to contain a 6. I also do that sometimes: If the solver found a particular nice step, he can use it again at a different (most often symmetric) position and hopefully feels rewarded. But some creators don't like that, because it makes the puzzle slightly easier and doesn't make you think again.

[@BlueCyann]

I loved that bit of repeated logic, personally. The set-up being slightly different is what made it work so well for me, meant the 126 payoff was a bit of a surprise. (Edit: Ooh, on watching the video, never mind! The set-up wasn't meaningfully different at all, I just took a more indirect path than necessary the first time.)

[@coolpapabell22]

Alternatively, as soon as you place the 3 and 4 in c9, the 9 cage in the upper right can no longer be 234. So it must have a 1 you can then place immediately. The extra 3 Simon used for that was unnecessary for that piece.

[@marshallgarey2913]

I wanted practice doing killer sudoku puzzles so I tried this one. Completed it in 56:16, but I did it without any help! It was a long time but I'm happy about doing it without any help.

[@ariel_haymarket]

59:13 - SUCH a wonderfully fun puzzle. And I got most of this by myself :D Thanks for helping me get past a stall-out in the upper left block, Simon.

[@garanceadrosehn9691]

I started with basically the same moves for the first seven minutes (though not in the same order), but then diverged a bit. This was a pretty enjoyable puzzle for me to solve. I always felt like I could see a "next move", without being stuck for several minutes without any good idea of what to try next.

[@chaotix37]

27:32 for me. That forced 1 got me there in rows 1 and 2. The puzzle is so creative.

[@busdriver1261]

This is my favourite variant of sudoku and this is a brillant variant of the variant! Lovely puzzle and love the logic in solving this type of puzzle. Thanks again Simon! :)

[@draconicdusk5911]

Though the path was pretty linear, there were multiple ways to solve this puzzle logically, loved it.

[@kazixo4788]

This was one of the most impressive and satisfying solves I've seen on your channel so far. Bravo!

[@ChrisWEarly]

Just found your channel the other day (thanks KZbin!) and I used to try sudokus when I was younger. Got your app and love watching these videos ☺️

[@Zylarlander]

After an hour and a half I gave up and decided to watch your video. I cannot believe that quintuple. Just wow.

[@gposchman]

Add my thumbs up. I keep working at killer sudokus. I can solve the easier ones and I have a pretty good understanding of using cages applied to 45, but I need to look up numbers in cage totals. I am just getting the hang of eliminating numbers within cages where a specific combination cant be used because it would destroy another cage. Hope that makes sense. Gene

[@yahya092]

I got an 89 pair in row 1 by noticing that 89 have to be in the 28 cage thus that only place for them in row 1 was to the left and right of the 9 and 8 cage. Then 7 is forced to be in the middle 3x3 so that gives 5869 in the for the 28 cage. 6 can only go in the 9 cage in row 1 so that gives me the 126 for the 9 cage. Really enjoyed spotting that logic

[@tomluo7178]

Nice solve, 17:38.

[@MiliRoot]

19:44.. wow, first time it didn't take me more than double time! But.. I solve killer sudokus on daily basis and I've seen quite a few videos here which made me pay more attention to the hidden tricks.. other types of sudokus shown on this channel still take me double time or more (when I manage)

[@ChristopherGermain]

20:28 on todays puzzle. Working on the Killer Sudoku app is making me better at these for sure!

[@WaswereRS]

27:18 pretty proud of myself, the 8 in the top corner, with the 1234 quad took me ~5 minutes of starting to find

[@BlueCyann]

Lovely, lovely puzzle! It was pure delight for me right up until I got stuck in resolving the middle boxes -- I'm looking forward to seeing what elegant piece of logic I missed there, because there must have been something based on how pretty the rest of it was. But hey, "can I really make 17 without a 1, 2, 4, 8 or 9" still got me there in the end. Took just under an hour with a few distractions. I'd like to say again how much I appreciate the clever puzzles featured on this channel. I've been computer-less for the last week or so, making do with a really quite decent paperback of mixed Sudoku-type puzzles in the meantime, but it's just not the same.

[@erickehr4475]

11 minutes 24 seconds. Nice puzzle. I’ve been doing a lot of killers lately so was “in the zone” for this one.

[@tadperry1817]

Trying it on my own as usual. It's taking forever. I immediately noticed the bottom right box with all cages and an extra square that needs to add to 45. Only two unique combinations give all digits 1 to 9 except for the one missing digit that goes in the square. So I got one naked single digit, and pencil marked two different quadruples in that box. Then I saw the bottom center box actually is basically is made of of 3 cages. (One unmarked area that could easily have been a cage with a 27 total.) After long and tedious calculations, I found three different possibilities that can go in the three areas and add to the given sums plus give all digits 1 to 9 once each. That's all I've done, but despite plodding along I might see what to do. Id Simon says he feels like a dullard again, I'm going to scream. I'm the dullard here!!! I can't wait to see him do it in less than 30 minutes, but that might be a day or two from now. Lol.

[@DanielMorris1]

I loved this one. Beautiful.

[@tadperry1817]

Was Simon's logic at about the 10:00 mark regarding the 8 cage in the top left box faulty and he got lucky? "An 8 cage can never contain a digit greater than 5, so we can put 12345 into these cells." What logically stops the 8 cage from having the 5 in question as the first cell in Column 2? Or what about the logic uncovered up to that point prevents it from being 1/3/4 with the 4 starting Column 2? Or is this perfectly legitimate to do, but he simply misspoke as he explained it. "This must include a 5 because we have 5 cells that need 5 different digits" seems like the actual explanation for doing it. Maybe I'm nitpicking, but I honestly couldn't follow why he did that when I heard it.

[@carreiras97]

Then at 11:17 he says that column 2, row 1 canno't be a 5 so the 5 in question has to be in column 1.. and I can't get why .....

[@espiritly]

I assumed that he skipped some steps in explaining the logic. He does that sometimes.

[@Kurgosh1]

26 hours, 30 minute, 34 seconds. Ok, I didn't work on it straight, but I honestly probably spent close to two hours grinding on this thing. And here goes Simon to solve it in 15 minutes. Sometimes I don't feel clever at all.

[@popolus1]

41:53 very fun puzzle!

[@tylerbenson3503]

Love the videos, have you ever considered using an eye tracker so we can see where you are looking while you are thinking? Could make for an interesting video.

[@ol1ver49]

Great puzzle. Satisfying to do it in a completely different order to Simon

[@theohill2521]

At 13:55 you placed the 8th one which randomly I noticed pretty quickly and then couldn’t think about anything else. Then literally the last number you inputted was the 9th one 😂

[@1fynn866]

It took me 1:23:04 but I solved it myself. My first killer sudoku by myself, I am happy about it

[@b1rdpoo]

just solved puzzle #40 in you sandwich sudoku app, omg is the only thing i can say. thanks for the ongoing content!

[@jonathanross6260]

Took me 1h30m... what a puzzle!

[@richardfarrer5616]

Good puzzle. Very nearly the same solve, although I worked out that the top right 9 must contain a 6 by looking at the rightmost column and using the same logic as you did for the 8 on the left.

[@clockworkseal2135]

I missed the 12345 quintet but got the 28 cage in the top middle because I realized that if it were 8947 there would be no way to solve the symmetrical 10-cages to either side, as there are only 4 options to make 10 with 2 digits and there would need to be a 5 in the crossbar of that cage's T for that to ever work. This led to me going up the middle first, then spreading out to the top corners with the 8 and 9 cage and using the 1-2 pairs scattered around along with a couple of x-wings to sweep through the right side, back down the left, and finish out in the middle

[@DerKarlKopp]

Took me 45 minutes to solve, very fun puzzle!

[@harmidis]

Killer Sudoku is 1000 times better than Sudoku. Thanks.

[@Ruddigore]

Great solve, did not try it myself but should have, it was well within my ability.

[@phos4us]

I went on a slightly different path at the beginning which got some digits in you got later on but I had to peek at your solve at one point where I got stuck for 10 minutes. It was the quintuple (12345). That helped.

[@tremkl]

I made a massive amount of progress in the first 6 minutes, then hit a brick wall and had a really rough time advancing. Ended up getting it but it took me 40 minutes.

[@TheMartyGangsta]

My first ever Killer Sudoku solve! Took me 1 hour and 5 minutes but I still felt like a Big Brain

[@DevilishlyDutch]

Alright so I needed quite a bit of hints to get through this (until about 13 minutes in), but I could think of part of the logic myself so that’s a win!

[@MinimumGnome]

Took me much longer because I didn't notice the Row 4 trick right away. Although I did eventually find it. Lovely puzzle.

[@Smaylik03]

An hour and 35 minutes with the 1-2-3-4-5 hint in column 1. I'm proud of myself.

[@rabidsamfan]

51:15. Had to beat my head against a wall there, but got through eventually.

[@SonGoku-tz9vt]

Hey, I don't know if you are familiar with a certain puzzle, you probably are, I'm quite new to the channel. Have you ever tried the "hardest sudoku ever" by Arto Inkala from 2012? If not, would you be willing to try it on your channel? I would really like to see you solving it

[@MichaelJPartyka]

Had to claw for every cell. Finally put it to bed in 1:14:45.

[@amoitouseule]

10:10 : how can you do that ? its not a quintuple since the 5 can be in some other place in that column; and the 5 can also be in the top right corner of that L shaped cage. If someone has an explanation..

[@charoox]

in the 5 highlighted cells in the first column, the only possible numbers are 1,2,3,4,5, therefore there is no other 1,2,3,4,5 in this first column Furthermore, since in those five cells the 5 can only be in the two top cells. Therefore it has to be in either of these two cells. Hence it is not in the top right corner of "that L shaped cage" (actually not in the whole top left 3x3)

[@helenetrstrup4817]

I was a bit stumped on how to even begin to fathom how to solve this one. I did get ahead of myself at one point and had to backtrack a bit. But eventually I managed to solve it. 😅

[@shane8037]

A killer I actually enjoyed. Unlike the guy who got my cat.

[@toadfrommariokart64]

:(

[@SinZ163]

Took me an hour and a half, I didn't see the quintuple on the left, and solved it by working out by theory crafting what r3c5 was, and seeing if its value (4,6,7,8,9) made the 8/9 cages possible. and it let me work out that it had to be 6, with r2c1 / r2c9 being a 12 pair, which gave me a chain of 12 pairs on r2c1, r9c1, r7c3, r7c7, r9c9, r2c9, meaning r5c1 and r5c9 could never be 1 or 2, making a 34 and 12 pair on r5.

[@travisholstine6046]

I can complete expert sudoku puzzles but I find that I’m lacking in some logic in places and end up making guesses when there should be some logic I’m missing to make it make sense. How do you identify what logic to use and where?

[@jasonheminger4844]

Can anyone post the link to Bastien's blog?

[@shane8037]

Nerf Bastien!

[@jasonheminger4844]

@@shane8037 ??

[@OjingeoChaemuchim]

Took 24:54, didn't know sum 10 trick on row 4 and 13 pair on upper middle square till the end.

[@EndlessMystify]

Took me 45 minutes, and I had to consult the video for help a bit, roughly halfway through.

[@shonuff5297]

I took similar path, but I went to the top to soon. I broke the puzzle in the end after about 40 minutes😋

[@AWanderingSwordsman]

Man, again I used different logic for a lot of it. Took me way longer cause of that. I get too caught up trying to resolve really complicated logic instead of just looking for simpler moves I think.

[@XavierShay]

you and me both! Took well over an hour and needed a hint from video on the quintuple on the left. More practice needed...

[@JalebJay]

(2,1), (2,9), (3,5) trio screwed me up. So many guess and checks weren't working for me.

[@kaiseremotion854]

You could have placed that last 1 much sooner because the rows and columns canceled the other possibilities

[@Bennatte]

39:34 with no help, though I kept making the same mistake somehow and had to keep starting over

[@williampowalski4222]

37 minutes. i suck at killers but this wasnt bad

[@Coyotek4]

17:30 Considering the mess I made on a number of puzzles I solved today, I think I'll quit on a personal high note.

[@PaulWilkinsNZ]

Adding images to the intro somehow reduces the enjoyment of figuring out who is who.

[@immabreakaleg]

quintuple find on column 1 smh

[@wossaaaat]

Let down by my appalling mental arithmetic once again. Was spotting the logic, but getting incredibly simple sums wrong. Very shameful...

[@boskayer]

First!

[@boskayer]

To comment* was implied, was that so hard to graps ?

[@shane8037]

@@stagj you killed him dude

[@boskayer]

@@stagj meh, intonation kinda gets lost in text. And usefulness and niceness are both intrinsically subjective.

[@PaulWilkinsNZ]

[sarcasm deleted]