The Worst Puzzle I've Ever Been Sent

[@DieHard111]

Die Hard Here. Thank you for the feature and the praise! I am so glad you solved this puzzle - I got as much enjoyment from your solve as I did from setting it. This puzzle was derived from another puzzle (Knight Shift), which you can find on LMD (a warning: this one is even more difficult) - but I had the idea that the concept would work even better as a fog-of-war puzzle. When I set the naked single 9, I knew I had to complete it!

[@longwaytotipperary]

What a fantastic rule set!!!

[@Paolo_De_Leva]

I can't imagine a more impressive and peculiar combination of such an original and masterfully described ruleset with such a cool, smart and magnificent construction. 👏👏👏👏👏👏👏👏

[@JaymanOttawa]

That was one of the coolest puzzles of all time! Bravo sir! :)

[@David_K_Booth]

I like the humour. You casually threw us the first digit like a dog biscuit, and we happily caught it, but then we found out we had to earn our supper. Lovely work.

[@kindlin]

@@David_K_Booth It was like an intro to the otherwise new and complex ruleset. By understanding the middle cell and the 2 rules, you get a small intuition for how the other rules interact on all the other cells.

[@charliec.6285]

My theory on poor ratings on Logic Masters Germany vis-a-vis Fog of War puzzles: Unlike other types, FOW puzzles can be brute-forced by trying digits until you see fog revealed. I've noticed that difficult fog puzzles on LMD are often "solved" by people who don't usually complete non-fog puzzles of comparable difficulty. If there are people who only complete a puzzle because of trial and error, I imagine they might be more inclined to give it a lower rating.

[@Robert_H.]

Sounds like they need an error score that shows how many wrong numbers a person typed in. I can't imagine who would end up going to the trouble of retyping the solution of the soduko with another account just to make a bad rating displayable.

[@Tahgtahv]

@@Robert_H.The problem is LMD doesn't have a Player, all you do is type in whatever digits are requested. For FOW puzzles, by the time you go to entering something on LMD you don't need to guess at the answer.

[@SilvrSavior]

Maybe a counter that is added to every time an incorrect digit is entered that can clear fog. The software is smart enough to check if fog is present then it clears it with a correct entry, then it should be capable of checking & tallying up all the incorrect entries.

[@charliec.6285]

The website doesn’t interact with any software. To mark a puzzle as complete you must enter a code chosen by the setter (usually the digits in a row and column that aren’t filled until the end of the solve).

[@_aullik]

The start of the puzzle is super easy and fog puzzles usually lead you on an understandable solve path. I got the 5 in the middle easily, then i made a mistake ruling out the 5s in the corner and placed the 1379 and about half a minute later i noticed my mistake but by then it was too late. I had a lot of fun watching Simon solve the puzzle, but it was definitely to hard for me and i should not have tried it.

[@DieHard111]

Die Hard Again. Thank you everyone for your all comments. And a special thanks to Simon for his incredible enthusiasm which is highly infectious. A few points of note: 1) Yes, it is possible to deduce that the corners are not 5s as a first step (this leads to a contradiction). But this does not take you very far, and I'm glad Simon found the naked single 9 first - which is exactly as intended. 2) Yes, it is also possible to deduce that R3C7 is a given 7. This takes a bit of look ahead (bordering on bifurcation), but it is a valid (if unintended) opening. Again, I don't think this takes you too far. A number of people have noted this won't clear the fog around the given digit - that is a feature of SudokuPad to signal its valid, but not the intended step. 3) I recognise not everyone loves this puzzle. That's OK. Simon's reaction made my year!

[@michaelawilliams]

I love it!

[@grithog5399]

I really wish the rules had indicated that the fog won't clear if the digit is a hidden given. It really set me back a bit since I assumed I must have made an error. Right, the 7 doesn't take you too far, but it can set you back quite a bit if you assume you made an error. Having the fog not clear seems more like unfair than it does "feature," especially since there is no indication that the "feature" has meaning. A great puzzle otherwise. A rules clarification would have tidied it right up.

[@Freeeez3]

@@grithog5399 very likely that die hard didn't know either, since this is technically a bug in the software.

[@v0id_d3m0n]

​​@@grithog5399 it does say "*may* clear the fog" rather than "*will* clear the fog" which could be an obscure indication of this

[@grithog5399]

@@Freeeez3 But he’s saying it’s a feature, right?

[@lunaverse4977]

I've been watching this channel for a few weeks, despite not having played sudoku myself since I was about 12, and for some reason i decided that THIS was gonna be the puzzle i tried for myself instead of just watching you do it. I must reiterate: have not done this since i was 12, and am now an adult. It's definitely NOT a beginner friendly puzzle, and i don't know what posessed me to choose it, but i did it. Took me 4 hours, but i did it.

[@tessabrisac7423]

Wow, congrats!

[@lunaverse4977]

@@tessabrisac7423 the satisfaction was definitely worth delaying my dinner until 10 pm, although i don't think i should make a habit of trying to solve puzzles right before cooking.

[@mostman]

Nice!

[@sirgeremiah]

I've been a regular sudokuist off and on for years, but never anything other than standard sudoku, and never the really hard ones. I watched two of Simon's videos and lept head-first into these bizarre variant rulesets. I'm still not very good at them (especially when they are used backwards, as with the knight's move here), but I love it, anyway.

[@OsnofAhcor]

that was brave

[@bobstreet2491]

I was surprised at how long you made us wait before mentioning digits "mutually satisfying each other".

[@TiagoMorbusSa]

That was pleasing.

[@Umbra451]

This is the orthogonal snake touching all over again

[@bbgun061]

Those digits are VERY good friends!

[@sirgeremiah]

@@Umbra451 Absolutely. Simon seems so tame, then does this so blatantly.

[@brookepearson]

@@bbgun061 all I can think of is "and they were roommates" lmao

[@pelahnar4]

Myvdad was reading a book about logic puzzles yesterday and asked if I'd heard of "Simon Anthony" who was quoted in the book and described as "making some youtube videos on sudoku" I completely blanked without reference to Cracking the Cryptic and said no, until it slowly dawned on me, the yes, I _do_ watch someone named Simon and...wait, yes his last name _is_ Anthony...

[@PauxloE]

This was the fastest first digit I ever found, but then I got stuck.

[@Schmogel92]

Interesting. If you copy the grid, rotate it around the center 180 degrees and add up overlapping cells you get 10 everywhere.

[@LithmusEarth]

Bro. That's so Wild.

[@athomasone]

Is there some kinda phistomafelesque thing that caused this? Or just some byproduct of the knights move constraint? Or Die Hard just made it that way?

[@melaniehall5885]

​@@athomasone I don't have the answer, but I'd guess it either has to do with some knights move black magic, OR the puzzle constructor figured out that it easily works that way, and did it because it was easiest to set. I'm leaning more towards the first one. Knights move can lead to weird logic shenanigans

[@simsplayer9952]

One other thing I saw is every # including the 5 has 2 boxes with the # in same postions.

[@jonotick]

Part of it is definitely a flow on from the fact the numbers obeying the box rule would add to 10 with their rotated pair

[@tarquinioprisco8459]

39:54 "2 is not 5, unless you turn it upside down" 😂

[@S_Black]

The break-in can also be argued by the 5 alone (and not some other digit). 5 automatically obeys rule C, but normally each digit can only obey one rule. Not two. So 5 in box 5 breaks that. The only way around is that is using the exception for the center digit.

[@thezanycat]

I’d argue the 5 isn’t the break in at all, rather Simon’s second placed digit is the true break in

[@0LoneTech]

​@@thezanycatBeing a bit stuck right there, I agree.

[@cerebralcomics]

Pretty cool how each individual digit is not only in its 3x3 box, but also in its cell. Amazing setting.

[@cryptikkcries]

OH YOU'RE RIGHT!!!!

[@mranderson978]

Actually the rules of the puzzle make this the only possibility, so Simon could have filled in those digits from the very outset. The knights move rule excludes them from being in any other spot.

[@challicerobinson6273]

@@mranderson978 That is what I thought too but was starting to wonder when Simon didn't get it. Only started to solve it myself when yelling at six months ago Simon through the screen didn't give him a hint...

[@IamNeminh]

​@@mranderson978 he did say that he saw the pattern but didn't want to fill it in because he didn't have the logic of "why" (?) so it would have been guessing, wich is not allowed

[@bananaman2]

I loved the symmetry of this puzzle and noticed early on how the positions of paired digits (1+9, 2+8, 3+7, and 4+6) swap places when rotated around the grid. I imagine that must be a consequence somehow of the knight's position requirements but I can't begin to plumb the depths of that logic.

[@Valkhiya]

So this is really funny, I actually found a bug (?) in the fog logic. In a board position very similar to 34:16 in the video, I deduced that r3c7 had to be a 7 (the 7 in box 4 helped me reach that conclusion), so I wrote down the digit, but because it's a given digit it actually just revealed that single cell and not lifted the fog around it.

[@dannyzwolf4546]

I think that works as intended, but you did stumble on an unintended solve path.

[@tenientebustillos4019]

This happened to me as well. It was not an actual guess but a deduction. Had to check the video to verify my input was correct.

[@RenameJames]

I love watching how excited Simon gets solving these puzzles. I can't help but get excited right along with him. This was a beautiful solve to watch. Simon was very Simon in this video.

[@brianarsuaga5008]

This was too hard for me to do fully alone, but I'm pretty sure this is my favorite puzzle on the channel yet. It's just so elegant, and it really felt like I was.. not so much teasing apart a beautiful knot, but being given a tour of this beautiful knot that someone discovered exists in nature. It was also amazing how many different ways you could apply the mutually-exclusive conditions, when at the start of the puzzle they seem to be saying nothing at all. Truly an achievement, thanks for bringing this to us all

[@pedrosaraiva1411]

Normally fog puzzles are easier for me than any other variants, because normally you have always some numbers or lines already revealed ,so its easy to understand were to start. But this one was absolutely brutal, because you even after put the 5 in the middle square , you really have to work hard to know where to look net.

[@AnaFromTheShire]

Ahhhhh my happy place, just as I've gotten home from a super hectic day... As someone with high anxiety levels which affect my life in multiple ways, Cracking the Cryptic, Simon in particular, has been an absolute godsend. I can feel the tension leave my body as I watch him go into battle with each puzzle. And on a personal level, his gentle and gentlemanly manner, compassion and wholesomeness are like a hug for my mind after dealing with a wild and sometimes terrifying world. I'm wrapped in warm blankies, got the cats lined up along me, hot choccy in one hand, and a big smile on my face! Thank you so much Simon and CTC, arohanui from New Zealand

[@ChasePhillips7]

Simon, you are a treasure in ways i can't possibly describe. You and Mark and your partners absolutely have an invite, thank you so so much for saying that about me and Cheryl and Vegas! If you need a physical invite, send me your mailing address and I'll prove it!

[@emilywilliams3237]

I am so glad that this channel solves these very hard puzzles on a regular basis. I always learn something about how to think logically, and, when I think about it, I realize that it was not all that long ago that a thermo sudoku would have seemed hard to me. So maybe these more complicated puzzles are aspirational for me in the same way that the types I once found difficult are now not all that difficult. Simon, the grid coloring, your reasoning and explanations, and all of your pencil marking all served to make this puzzle make total sense. Am I going to turn around and solve it? Not today. But sometime, maybe ... Oh yes, one more thing that was impressive was that the fog was meaningful in this puzzle, and because it was completely fogged over it did not lead the witness, so to speak, as much as other fog puzzles often do. Thanks so much, Simon. I loved it.

[@bobblebardsley]

Agreed, and why I don't complain about hour-long videos even on days when I don't have time to watch them in full, I'll always try to watch the break-in and learn from that. I'll usually only attempt the puzzle if the video duration is less than 30 minutes AND I understand the rules, otherwise I'd still be solving it by the time tomorrow's video pops up!

[@davidmiller9485]

@@bobblebardsley Which is cool and all but I like the longer videos because I get to see Simon solve using various form of logic (form being used sorta loosely here). That's the great thing about recorded video. You get an opportunity to watch the video based on the time constraints that each person may be dealing with.

[@bobblebardsley]

29:26 "And this is going to be lovely, because it's going to allow us to sing 'Ah, You Rotten Thing'." All together now...! Ah, you rotten thing! How dare you give me naught? How dare a digit bring less logic than it ought? I went the long way round to prove what you must be, and yet you, rotten thing, gave nothing back to me. Bobbins, bother, blast! I loudly vent my wrath while moving not-so-fast along my logic path. Now digit, can you tell how grumpily I sing? You scoundrel of a cell; You rotten, rotten thing.

[@RomanKrow]

@@bobblebardsley this is brilliant!

[@bobblebardsley]

@@RomanKrow Thank you 😊

[@rokualvin6428]

You have multiple nearly superhuman skills. It is a given that you have a brilliant mind for solving Sudoku puzzle. But you also have an incredible gift of sharing your thought processes on the fly. You bring the viewer along with you as you work. This combination is fantastic for a KZbin Channel. And finally you have an enthusiasm for what you are doing, that is infectious. It is like a treasure hunter following a map, and feeling joy at each intellectual discovery, and not only feeling the glee of discovery, but sharing it with the viewer. I truly enjoy watching your videos!

[@guyb7005]

49:18 I'm shouting at my screen "7 in box 8!!!" but alas, I am too entertained by your articulate wit and eventual mastery

[@Sidnv]

"Deadly pattern somehow resolving itself": Simon, Die Hard gave you the digit that resolved it :)

[@radvermin1541]

Was getting frustrated with the extra hard sudokus I was attempting. Found your channel and saw how to think through the harder ones. I can solve them through simple deductive logic rather than guessing. Thank you for your channel. I'm enjoying them again.

[@thecalculusofexplanations]

I would love them to use some sort of eye tracking software for a solve, I think that would be fascinating.

[@iancastro2414]

Fun fact, it's possible to prove that the corner digits are 1, 3, 7, and 9 without using the numbers "given" in box 5. You can only put 1 in row 1 in the cells R1C1 or R1C2, if you try to put in any other cell, you will get the following: * R1C1 will be 5. * R1C9 will be 3. * R1C2 will be equal to R2C4. * R1C8 will be equal to R2C6. And there is no place to put 5 in box 2. If you apply this to column 1, you will have that in column 1 the 1 can only be in R1C1 or R2C1, so to satisfy both conditions the 1 must be in R1C1. The same applies to 3, 7 and 9 for cells R1C9, R9C1, and R9C9, respectively.

[@Rob-oj9bj]

One issue I came across while solving: If you put a correct digit in the puzzle which is also a "given" under the fog, it no longer clears fog AROUND the filled in cell. Not sure if this is intentional, but the first time it happened I thought I had made a mistake (filled in r7c4, nothing around it was cleared. Only indication that I had a correct digit, I realized after a moment, was the digit was black and not blue.)

[@RichSmith77]

This issue caused me to waste half an hour rechecking logic that was correct all along. (Wasn't helped by having pre-coloured the cell, so the fog lifting just in the cell wasn't noticeable.)

[@stephenleow9876]

I spotted some faulty logic that gave a 2 early at: 29:00 A 2 in the middle of Box 2 is NOT in its own box; it's in square 5 of box 2. I believe the correct logic would be to get the 2 in box 9 first, then once you have the 2s in columns 3 and 7 you can properly get the 2 in column 5 and go from there.

[@simonramchandani9560]

@@stephenleow9876 jep ive also seen that

[@Bonehead777]

Someof the ratings on logic masters are just wrong because it depends who has solved them. There are definitely some folk who solve puzzles and just give them terrible ratings. No idea why it means that much to them. I have literally watched updates on a few of my puzzles and noticed big drops in ratings with certain solvers. And I know when I have created something that in no way deserves the lowest marks. I will bet that I am not the only one who has spotted this. Of course, the vast majority of solvers are completely fair so if a puzzle has a lot of solves, it is much more likely to get a fair rating for its’ quality.

[@charliec.6285]

I think that's just the riSK OR Peril setters have to be comfortable with when posting their puzzles there.

[@Bonehead777]

@@deadeaded yeah,it is a real shame. Won’t stop me posting though. 🙂

[@Bonehead777]

@@charliec.6285 It is. Hopefully, eventually I can get enough of a name for good folk to always have a try. 🙂

[@BigAsciiHappyStar]

Ouch!

[@Jagnathbaba]

What I like about this puzzle is the fact that the conditions are relatively easy to understand but you have to keep thinking about its implications on different positions in the sudoku. Like, how you started with a 5 in the center, then went to the corners and then went to the middle cells etc. You basically keep discovering new things which is amazing.

[@hewholimpsmartin]

That is terrifyingly amazing Excellent solve

[@dannystirling5458]

This puzzle was an amazing watch! My favorite moment was my realization that, with only 1 one on the board, the pink squares at 51:11 had to be a 1, since every other digit breaks a rule.

[@awilliams1701]

I noticed that each digit had to appear in it's own cell in its own box. when the box positions are numbered the same way.

[@memyself8340]

From 13:31 to 14:50, Simon explains why his "5" pencil mark is removed from fows 2 & 8, and columns 2 & 8. Which then removes 5 as an option in the corners. Then at 20:05 to 20:20 he almost sees it again. I love it when I see a logic that he doesn't, but he always finds lots of ligic that I don't. Therefore, he always wins and I am entertained. Thank you Simon. (If you ever hear me yelling at the screen, just remember that I have time to scan while you are doing the hard work.)

[@davidhughes7174]

A fog of war puzzle that turned into an amazing sudoku puzzle that ended up being re fogged in blue. Astonishing, again. Thank you Die Hard and Simon.

[@BanaiFeldstein]

If you stick with the fives at the beginning, plus look at those cells where there's only one place to put a number a knight's move away, you can figure out that five can't go in any corners because they have nowhere to go in other boxes, the stuff he got to somewhere in the 40-50 minute section.

[@DominikWegerle]

That was my thinking as well, but i'm not shure if that can be logically deducted. He mentioned it at 13:35 and then never ever got back to this restriction.

[@altaybatuhan4560]

26 minutes in MY MIND IS BLOWN WHAT IS THIS PUZZLE

[@TheDecagn]

I came to get a hint on this puzzle as I got stuck when the number 7 in box 3 (bottom left of box 3) did not reveal fog. After looking at the correct digit that simon put in, i saw that it is the same as I put in, so I’m annoyed that i spent so long trying to decipher why I was wrong when in reality I wasn’t, but the fog just decided to not reveal the surrounding area for some reason EDIT: after following through, I recognise that i managed to decipher that a 7 was there even though it was already given (after you clear fog), which is funny as from what I can tell, that 7 did not need to be a given!

[@JasperJanssen]

Maybe it was given precisely to avoid fog lifting?

[@michaelawilliams]

Simon says "if there is a 9 here, then there must be a 9 there"... then he proves the 9 goes there and completely forgets the other 9 for the rest of the solve.

[@matthiasvancampen3770]

I think I might've overanalyzed it today. But you can now from the very bezinning (after putting the 5) that the corners are 1,3,7,9. Take a look at box 2 for example: the 3 bottom digits AND the central digit need to make an appearance in row 1. However as the central 5 sees all of these and they either rescue a number from row 1 (r1c3 or r1c7) or they must be special. Since two digits of this 4-some need to be special, you know they're the 1 and the 3 in row 1 that don't need to be 'rescued'. By symmetry 1 and 7 appears in column 1 and don't need ti be rescued. Therefore 1 is in the top left cell of box 1.

[@cinny.]

This whole puzzle is really easy, actually. When you find 1 number, you immediately find another number. each number on opposite sides of the board (opposite sides of a line from bottom left to top right) add up to 10. Im pretty sure(?) this is correct

[@handtomouth4690]

​​@@cinny.And you just assumed this for the whole board right from the start?

[@SuperPlienie]

I like all the puzzles but the fog ones always make me very happy!

[@eddieharwood7788]

That was a really hard break in, but the thing that really held me up was nearing the end when a 9 failed to clear fog. I deleted a long way and got to the same point, so I went back almost to the beginning and still had the same problem. Then I though that perhaps I had accidentally coloured the cell with dark grey and lo and behold the gog disappeared. What a numpty!!!

[@JakeRoeder]

It would have taken me DECADES to come to the conclusions that Simon needed to move forward after recognizing the corner constraints. But, man, was that ever the most brilliant deduction! Well played, Die Hard, well played.

[@thomasstubtoft2544]

the way to logic the 5s away from the corners is to think of a cell next to the corner, ie. r1c2. Either it is a 5, which would prevent the corner from being 5, or it is not a 5, moving the 5s in the middleboxes to the edge by kingsmove, and again preventing 5s in the corners. Once I saw this and Simon did not, I could not keep watching as my yelling at the screen became to loud :) .... an skipping to the end, of cause Simon, master solver as he is, found another way.

[@PeterFreese]

Right - this would have immediately given him all 4 corners for 1,3,7,9.

[@TeamCykelhold]

Hmm...the 2 in the fourth box meets two conditions. That breaks the puzzle, sadly. Same with 8 in the sixth box, 7 in the third box and so on. Is it me who doesn't understand the rules or what? They are constantly broken when a digit is both in its own box and a knights move from itself.

[@wilmirosa7076]

Same, the 3 in the box 7 also breaks the rules, I don't get it

[@funnyjesterman]

"Box" in the rules refers to the 3x3 grid. Box 1 is the top left 3x3 grid, Box 2 is the top middle 3x3 grid, etc. It has nothing to do with where a number is specifically inside of a box.

[@handtomouth4690]

Not to be a rude(but a little bit), but should probably learn sudoku terminology before criticizing puzzles, especially this one that literally explains to you the box concept in the rules.

[@TeamCykelhold]

@@handtomouth4690 Lol yes that was rude and assholery. No need for that. I asked if it was me who did not understand the rules. Instead of explaining why, you make a fool out of yourself being an asshole. I later understood what was going on, but it doesn't matter. Your comment didn't bring any value whatsoever, and I see that many other poeple didn't quite get the rules as well. I didn't critisize the puzzle, I merely asked why something was seemingly wrong. See if you can manage to not be such a d1ckwad in the future, people will thank you if you can turn yourself around.

[@titusadduxas]

I assumed 5s couldn’t be in the corner because I thought that with knights move puzzles Phistomofels theorem stopped the centre digit being in any of the 4square corners.

[@RichSmith77]

Sorry , but that's not the rule. If a digit is missing from the Phistomefel ring, then it has to go in the centre. But this only applies that way round. It does not mean the reverse, that a digit in the centre cannot appear on the Phistomefel ring.

[@NightChime]

1:00:59 - A tidbit of logic I enjoyed here in box 9 with the 146s, is that because the grey digits can't be 6, there must be a 6 between red and green. Take that to box 8, and the orange digit is 14. Granted, I don't recall if that does a whole lot, but it's a fun little extrapolation.

[@altreusplays]

This rule set is tremendous! I love the device of requiring each cell to meet one rule but not more than one.

[@LarkyLuna]

I was trying to set a "digits see themselves on knights moves" sudoku on my free time This will be inspirational lol

[@jrparker811]

This is an incredible work of art. A beautiful puzzle. Everyone should give it a go. There are logical conclusions on the placement of digits just from the rule set. Then the fog starts to lift.

[@pianissimo7121]

the box number digit always has to go in its own cell, ie, 1 in box 1 goes in cell 1 and 2 in box 2 goes in cell 2 etc. This can be done at the very start itself without needing any other clues simply because of the ruleset. That is amazing. Edit: I might be completely wrong. Need to check my logic. If someone else can prove/disprove me please feel free to do so.

[@adrianhead6272]

I thought that too. It just seemed so obvious and yet no one (Simon included) mentioned it. It's probably why it got the average rating.

[@pianissimo7121]

@@adrianhead6272 i didn't find that logic myself. I only got it after Simon pointed out how row 1 and column 1 works with the rules. What's funny is i thought Simon would find this when he mentioned about the 1,2,3 and 5 being in their own cells and then he forgot about it.

[@RichSmith77]

Why does 1 have to go in position 1 in box 1, etc? That doesn't follow automatically from the rules.

[@pianissimo7121]

@@RichSmith77 it kinda does. If 1 isn't in cell 1 in box 1 then the 1 in row or column 1 from box 2 or box 4 respectively will have to be a knights move away from box1 1. This means box1 1 is following 2 rules which is illegal, so the only way it can satisfy a single rule is if it's in box1 cell 1

[@RichSmith77]

@@pianissimo7121 Sorry, I must be being slow. Why can't the 1 in row 1 be in box 4 and be a knight's move away from a 1 in box 7 (or vice versa)?

[@rizka7945]

Interesting how you can start the puzzle with (at least) two different logics: 1) Simon argues that for the center cell to fulfill two conditions it has to be a 5. 2) My argument was that the 5 in the center box automatically fulfills at least two conditions so it has to go the center cell.

[@gogogo123454321]

That's the same logic.

[@steve470]

@@gogogo123454321 "There's only one digit that can be placed in the central cell" and "There's only one place 5 can go in box five" are not the same logic.

[@mareksroka5629]

@@gogogo123454321not quite. One is saying that the center cell can ONLY be a 5. ("what are the option for that cell?") The second is saying that 5 can ONLY go in the center cell.("where can 5 goes in box 5?")

[@rizka7945]

@@gogogo123454321 It's the same conclusion through different means.

[@Mennoo_]

I remember this one while it was still up for testing in the CtC Discord server. Unfortunately it had some issues with pencilmarking foggy cells, where given digits in the fog couldn't be pencilmarked. Lucky that issue has been resolved by Sven. When I tested this, I made one assumption that the corner cells would be the box numbers, and was able to continue from there in the the version of the puzzle at that time had much more given digits in the corner boxes. Problem at that time was that a lot of pencilmarks would had to be eliminated by a suddenly revealed given digit. It's good to see that Die Hard significantly improved that process. The puzzle seems to flow much more natural now. Die Hard later explained in the discord server the method involving those digits against the middle of the centerbox' edges, but I didn't quite get it at that time. So thanks a lot for explaining that part so clearly. Only really good sudoku solvers would be able to deduce such logic. If you are able to put such logic in your puzzle, you deserve nothing but praise for that (and definitely more than a 74% rating). In my opinion, people shouldn't rate puzzles on LMD very low (unless it's obviously designed very badly). Even if you don't like the solving partly, there is always a part where you can at least admire the logic that went into the puzzle. Every puzzle on LMD is created by someone who spent time on it, and imo that should never be demotivated by a ridiculously low score. I saw it also with my first puzzle I posted on LMD (still my only one for now). It got to a point where it was rated very highly with 95%, but one 0%-rating dropped it to 90% (puzzle has 5* difficulty, so not many solvers, hence a bigger impact). And even tho he messaged me with reasoning and feedback which I do appreciate, I still believe that 0%-ratings would be irrationally low, and either 40%-ratings should be the lowests you should give for a puzzle for which you see time and effort has been put into it. Nevertheless. This puzzle and the solve path i've seen now deserves all the credits. Good job Die Hard!

[@brunomcleod]

1:07:49 the subtitles interpret the f and the d (the frequencies of the other notes likely come into it) as the word "thank" and "you"! That's awesome

[@peterhowitt3861]

I was totally baffled by Simon's logic path on this one, unless I completely misread the rule which I don't think I did.

[@ArseneMichiels]

Hey! This was a fantastic puzzle. I was surprized when i saw the video because you didn't need to use the same start as I did (except for the five, obviousely). I started by proving, I think, that the corners needed to be digit of the box (n in box n). Because if let's say (1;1) is a 5, then either (2;4) or (2;6) is a five which means either (1;2) or (1;8) is the number of the box (because it only sees a 5). It can't be (1;8) because it would force (1;9) to be a 5 wich would break the sudoku. so (1;1) being a 5 would imply (2;4) being a 5 and (1;2) being 1. Repeating this vertically would then imply for the same reason (2;1) being 1whicl leads to a contradiction. By symmetry, I could immediately write the four corners. I was so prowd of this and I am amazed that it was not needed. Sorry for my pour englich. I hope this is understandable ;)

[@austinsinger7565]

I had to start over because I got stuck. After watching a few more minutes of you, I realize I had the rules wrong. The second was way better. I finished it in 40:25. Yay it felt good to finished one. This is my first solved puzzle since watching you. Now I can go back to see how you solve yours. I learn doing the section b first really help.

[@steves1371]

I did it in 82:25, my first solve of a puzzle from this channel!

[@studgerbil9081]

No idea why this was rated so low. The ten digits were hardly given since they were obscured. The break in "5" was easy but nothing else was easy at all.

[@NeilCrabbe]

I haven't got to let's get cracking yet, but my first thought when I saw a completely blank grid is there's a 5 in the middle. Then I read the rules and I still think there's a 5 in the middle. Is this the Dunning Kruger effect? Have I been watching CtC long enough to think I know what I'm doing?

[@darthrainbows]

Brilliant puzzle! I had a devil of a time getting the break in, but once I figured it out, the solve was very satisfying.

[@mike1024.]

I love the way this puzzle starts right off the bat.

[@Raven-Creations]

I know apprentices on their first day are often sent to the warehouse for a bucket of blue steam (and make sure it's fresh), but a bucketload of fog? I think the reason for this puzzle's fairly low difficulty rating is either that people overlooked the possibility that the corners could contain 5s, or they figured out why 5 cannot go in any corner. @ 27:41 - "that's not how to do this" - You were so close to figuring out why 5 cannot go in any corner, you just needed to think a little longer, but you gave up. The digit corresponding to the boxes on the edges must be in their edge's row/column. Therefore 1 in box 1 must be in R1, 2 in box 2 must be in R1, and 3 in R3 must be in R1. However, this applies to the columns too, so 1 in box 1 must be in C1, etc. This means 1 must be in R1C1, and similarly for the other corners. If you'd spotted this, your solve would have been much, much easier. Although X was in position X in box X for all X, I couldn't figure out if this was forced by the rules, or whether it worked out that way for boxes 2, 4, 6, and 8 under the influence of the given digits. This was a brilliant puzzle, that falls into the "discovery" class. I'll remember this one for a long while. A nice ruleset, especially when combined with FoW. I thought that the rules could have included some fake rules like arrows, or kropki dots to give you hope for more helpful revelations as the fog cleared. It was clear from the rules that only additional given digits could be revealed.

[@wolfieisacat13]

Seeing him struggling to kick it off comforts me bc it shows that even experts struggle sometimes :)

[@escapedlunatic27]

I did solve this eventually, but there were a couple of points at which I had to "cheat" by guessing. Fascinating to see the deductions Simon made which I missed - but even more so that such a puzzle can exist at all. It seems amazing that just those conditions, and the specification that (except for the centre cell) they're mutually exclusive, can not only lead to a unique solution but make it possible to deduce. Kudos to the composer.

[@ianward71]

Wow.. what a beautiful puzzle and a great solve by the maestro. Kudos to Simon and Die Hard

[@derekswager]

at about 50 minutes into the video I noticed the 10's compliment rotational symmetry

[@penningmeestercgkdelft9159]

Maybe Die Hard could also design a Jules Verne-themed "Phileas Fogg-Of-War" puzzle, named "Around The World in 81 digits", with a nice Passepartout around the grid...? Surely he could Fix this...

[@Anne_Mahoney]

That's so clever that somebody's *got* to take it up! 😸

[@koenth2359]

Here's an idea maybe for Sven to consider, in order to discourage just guessing to clear fog. Wrong guesses will increment a variable keeping the wrong-right count balance for that cell, and every time the right number is entered, it will decrement the cell's variable again. Fog will only clear once the count is negative. So if, due to a mistake, the fog does not clear away, you'll have to enter the right number twice (by entering it, erasing it and reentering).

[@longwaytotipperary]

Oh yay! Foggy puzzle!!! Recovering from nasty virus watching all my favorite KZbins and eating ice cream!! Feeling much better!!

[@lexifer1711]

took me like 6 hours but i enjoyed the heck out of it. i solved it in a different much worse way lol its really a pleasure to see you work through these so methodically.

[@fynnsternis6432]

i love negative constraints like that but they are usually the hardest because you have to think so much differently

[@MikeMJPMUNCH]

I'm confused by the rule set as it says "Each digit satisfies only one of the following conditions" but there are a few numbers that are both a chess knight's move away and in normal reading order.

[@RichSmith77]

"in reading order" just means the boxes are numbered left to right, top to bottom, so 1 2 3 4 5 6 7 8 9 Condition 2 is met by any digit in its box number, e.g. the 9 in box 9 (the box in the bottom right).

[@TeamCykelhold]

@@RichSmith77 yes and plenty of them are and satsified more than one condition since they are ALSO a knights move away from itself. Look at number 2 in the fourth box.

[@RichSmith77]

​@@TeamCykelholdThat's only satisfying condition (a), namely it's a knight's move away from another 2. It fails (b) as it's in box 4, not box 2. It fails (c) as it's not a 5. So it satisfies exactly one of the three conditions. The position within a box is irrelevant. The boxes (not cell positions) are numbered according to reading order. Box 2 is the top middle box. Only a 2 in box 2 has to avoid being a knight's move away from another 2.

[@TeamCykelhold]

@@RichSmith77 Aah ok I see. Thanks.

[@inspiringsand123]

Rules: 01:47 Let's Get Cracking: 08:05 Simon's time: 57m51s Puzzle Solved: 1:05:56 What about this video's Top Tier Simarkisms?! Bobbins: 1x (33:21) Knowledge Bomb: 1x (10:33) Three In the Corner: 1x (29:38) Cooking with Gas: 1x (15:40) You Rotten Thing: 1x (29:28) And how about this video's Simarkisms?! By Sudoku: 14x (10:00, 50:04, 51:23, 52:04, 53:32, 57:26, 58:09, 58:12, 59:27, 59:30, 1:00:05, 1:02:40, 1:03:09, 1:04:35) Ah: 12x (01:14, 12:14, 12:14, 20:45, 25:32, 29:28, 40:27, 41:17, 49:04, 56:37, 59:01, 1:03:27) Hang On: 11x (03:54, 25:23, 25:23, 45:02, 45:02, 45:54, 45:54, 46:50, 56:28, 56:34, 1:05:59) Sorry: 6x (00:37, 15:44, 19:18, 27:33, 33:24, 1:05:32) Obviously: 6x (02:09, 04:12, 09:57, 16:26, 27:02, 1:05:43) Incredible: 5x (26:38, 59:49, 1:06:53, 1:06:53, 1:07:28) Nature: 5x (26:31, 34:06, 51:12, 57:14, 1:06:40) Pencil Mark/mark: 5x (33:56, 36:17, 40:08, 49:06, 55:06) The Answer is: 4x (21:40, 37:07, 41:53, 56:49) Surely: 4x (31:28, 39:20, 54:28, 1:07:26) In Fact: 4x (07:20, 22:49, 39:46, 1:02:54) Beautiful: 3x (05:57, 31:40, 31:40) What Does This Mean?: 3x (09:16, 47:42, 57:20) Naughty: 2x (25:39, 42:10) Lovely: 2x (29:27, 59:15) Intriguing: 2x (00:30, 05:27) Good Grief: 1x (40:16) What on Earth: 1x (35:51) Goodness: 1x (26:25) Out of Nowhere: 1x (51:23) Nonsense: 1x (29:20) Bingo: 1x (25:20) Stuck: 1x (47:57) Horrible Feeling: 1x (19:18) Brilliant: 1x (1:02:54) Break the Puzzle: 1x (24:35) Fascinating: 1x (26:16) Extraordinary: 1x (05:10) Ridiculous: 1x (1:05:53) Deadly Pattern: 1x (49:22) Unbelievable: 1x (26:19) Full stop: 1x (1:06:11) Whoopsie: 1x (53:25) Fabulous: 1x (36:46) Juxtaposition: 1x (59:15) That's Huge: 1x (56:37) Panache: 1x (1:06:34) Cake!: 1x (07:53) Ab Initio: 1x (16:44) Symmetry: 1x (16:36) Most popular number(>9), digit and colour this video: Sixty, Seventy Three (2 mentions) Five (123 mentions) Blue (21 mentions) Antithesis Battles: Even (2) - Odd (0) Shaded (2) - Unshaded (0) Outside (2) - Inside (0) White (2) - Black (0) Column (20) - Row (13) 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!

[@maoman4855]

Why did I have to scroll so far to find this comment!? You're usually up near the top.

[@Zorrky]

My eureka moment was when i realized the box digit has to be in the digit number place as well. Strange Simon had that idea as well pretty early, but he didn't think it through and the key being the middle digit what do 2 conditions at once. But for every other digit, in order NOT to meet 2 conditions, they have to all be in their digit place on it's own box. And you can pretty much deduce at the very start, almost making the whole puzzle visible. Very nice! :)

[@SG2048-meta]

I just don’t understand this though. I can’t figure out why the box digit will satisfy 2 conditions if it isn’t in its digit number place. I’ve been thinking about this for a while but I really cannot figure it out. Can somebody explain this in simple terms?

[@Zorrky]

@@SG2048-meta Because othervise you just couldn't fill row 1, column 1, row 9 and column 9 with the digits 1 to 9 (once only for total). As you can see, the digits are all are on the perimeter and since normal sodoku rules do apply, every box contain it's own digit (like box 4 must contain a 4), but that's already meets it's requriment. Now, if you don't put 4 (in box four) to it's number place, you literally can't put 4 in row 1 to meet it's own condotion or if you do, it will break the "only one condition can apply" rule. Try to just put 4 in anywhere else in box 4 than it's own number and you will realize, in column 1, it MUST be there. And that logic apply to every digit in it's own box. But it was an eureka moment, i can't recall my tought process quite clearly now, it happened in an instant.

[@SG2048-meta]

@@Zorrkyaaah I see now!

[@Mephistahpheles]

@40:00 Simon gets the 2 which was my first digit. I used the "2 in it's own box" which forces the 2 in box 1 to be paired with a 2 in box 4. That quickly leads to the 2 in box 9. And that's the end of my "brilliance". Didn't get far in the puzzle at all. I was somewhat surprised Simon didn't pick it up immediately after the "naked 9". The two 2's in rows 6 & 7 force it, as well.

[@VeritasUnae]

Such a sublime rule set. Very cool to see this solve, even if I didn't have the time to spend giving it a go myself tonight.

[@PeterFreese]

I kept shouting at the screen that the 5's had to be on the outer edges of boxes 2, 4, 6, and 8, because they were blocked by knight's move by the cells directly adjacent to the 4 corners. That would have jumped you along much more quickly to getting all the 1-9s in their own boxes, but you found other ways to make it work. :)

[@scarfboyxiv]

Let me start by saying this is my first solve of any puzzle featured by the channel. I started watching last year and have always been a huge fan of sudoku-style puzzles-the wildest variant I had tried beforehand was Wordoku, but there are only so many non-repeating 9-letter words. The Fog of War mechanic really intrigued me since Simon started featuring such puzzles. I had always been curious to try solving some myself, but I always ended up watching the video first. I feel that if I immediately go to solve the puzzle after I watch the video that feels like cheating. This unique ruleset really spoke to me, though, and so I finally tried my hand at the puzzle first before watching the video. What fun this puzzle was! Now, granted, tricks like The Secret™and the Phistomephel Ring are not as useful as they typically are, and I have not watched the video as of this writing so I have not learned Simon's newest discovery yet, but this was a fantastic test of logical digit placements! I started my reasoning with the center digit as there was an obvious way to fulfill its exception but worth it to prove to yourself why it works that way. I also took longer during my solve to fully understand the true meaning of the second constraint-whether that placement was intentional or accidental-as I kept telling myself that the logic behind it was fallacial. As Die Hard explained, guessing was not allowed so I forced myself to explain to myself why that placement works. I did get there in the end after solving completely for the 2s, 7s, and 8s starting with box 9. 4 and 6 were definitely my hardest digits to place, especially in reminding myself that no knight's move can reach the digits in their respective boxes. I did almost fall for that trap in my logic. Twice. But when I noticed a certain special property of the center box, everything else pretty much fell into place. You could say Die Hard summed it up nicely. (I did take a curious peak into the comments in the middle of my solve and saw some people saying things about other transitive properties of the puzzle, but that all flew over my head pre-video-watching.) I also did get confused by R4C2 with SudokuPad's "feature", but thankfully I noticed the shadow of the fog breaking away. Oh, and the black number eventually. I finished with a time of 158:26, though I think a sixth of that time could be cut for formatting my solve. I don't have Simon's fancy setup and I color coded each digit. I'm still proud I managed to solve this puzzle. Die Hard, thank you for inspiring me to actually solve one of these. Like I said at the start, this was a fun solve! I can't wait to see more of these kind of foggy logic restraints in the future.

[@mackenziearchitects]

I've been doing sudoku (at best to average level) for years without knowing there was an 'adjaceny' rule........... Doh! Came across this site yesterday & this puzzle today. Made good progress on this one by learning that u gotta read the rules, CAREFULLY. Onwards & upwards.

[@Amelie-lq3zi]

what’s so funny is that he just gracefully solves these really hard puzzles but constantly misses the really easy sudoku stuff

[@HalfBakedLunatic]

Excellent! I have a few puzzles on Logic Masters Germany where I think the ratings have been unfairly stifled ... so I know how you feel!

[@randomjunk1977]

As a shorthand for the "knights move domino" situation, which isnt really a domino, I propose the name "charlie horse"

[@nightmotherasmr]

I don't understand any of this, but I love how happy Simon is when he figures something out :) I just watch for the positivity.

[@andilee3537]

I think the rating is about right. It has a fascinating break-in the early part to clear some fog is full of discovery, but eventually it just descends into a horrible morass that has no clear path through it. A great idea that had a terrible ending. I got so bored i gave up shortly after clearing all the fog.

[@justinfarmer8371]

Only Simon can get excited for the same logic in the same puzzle lol grate solve

[@curtiseichner1306]

3 in the corner, losing its religion. 5 in the middle, gaining its condition.

[@chocolateboy300]

I finished in 241 minutes. This one was hard. I was able to get a couple digits, being 2s in r2c1 and r4c2, and 7s in r5c3 and r3c7. The 7 in r3c7 confused me as I put it in, because no fog cleared. I realized why, because it is a given. How strange? I got hard stuck and could not make any progress from there. I had to give up and watch the video and see that Simon points out the restriction on inner center cells of boxes 2,4,6, and8. That was finally enough to get me to finish. Great Puzzle!

[@wolfmoon5720]

Funnily enough each digit being in its own position within its own box was how I initially understood the condition in the rules. Felt silly when I saw how Simon interpreted it so it was nice to see they did follow what I was originally thinking as well!

[@joeg451]

"Two is not five, unless you turn it upside-down" Simon, I have a secret to share with you...

[@lin-ni2885]

there was nothing more infuriating than having you have eight sevens and then just moving on to another digit

[@sakkikoyumikishi]

I think this is the first time *ever* I got to the break-in faster than Simon. As soon as I read the three conditions (even before I got to the part about the exception), I realised that there must be some shenanigans going on with the 5 in box 5, since there is no way only one of these conditions can apply to it *and* normal sudoku rules still be in place. So when I read that the centre space fulfills two conditions, the break-in hit me right away. Very fun It's also possible to immediately deduce quite a bit about the very corners of the grid. Since those can never fulfill condition a) (since all cells that are a knight's move away from them are also in the same box with them), they have to be either a 5 or the number of the box. We obviously can't have more than two 5s in the corners, so the options for the corners are, going clockwise, 3 or 5, 9 or 5, 7 or 5 and 1 or 5, and we know that *at most* two of them are 5s (and if there are indeed two, that they must be in either box 1 and 9 or box 3 and 7). While this is not immediately useful for another digit, it does put a fair bit of pressure on 5s... and also means we have an at least 50% (potentially better) chance of a three in the corner 😉

[@EwYoureCringe]

Me the first 10 minutes: “THE CORNERS, THE CORNERS” lolol

[@rectrlgaming]

don't know if anyone noticed this but there is a flaw in the rules , that is the five in the middle box (5) either satisfy three conditions if its in the center or two if its not and that is not allowed.

[@epylar2]

Two is allowed

[@rectrlgaming]

@@epylar2 but three?

[@handtomouth4690]

​​@@rectrlgamingwhat's the third condition? It certainly isn't a knight's move away, so it literally can't fulfill 3 conditions.

Wonderful puzzle! Knights move relations are a fascinating subject. Note for the cognoscenti: sudokus with a great amount of symmetry in its solution grid has its equal digits in knight move relations. Known for setting symmetric puzzles I have set puzzles where all digits are in knights move relation when you view the grid in a toroidal manner. This puzzle makes clever use of not viewing the grid in a toroidal manner and the fact that numerically symmetric puzzles has the digit 5 in the center square.

[@danielepicone1480]

I tried this puzzle myself and the second digit I got was r3c7, which to my surprise was a given digit and hence did not reveal any fog! I think this bug is part of the reasons why it has such low rating.

[@Jesthers]

Had to watch to 37:06 to solve. Absolutely wonderful puzzle. After that break-in it was a great time of me tying digits together in a little buddy-system, deserved recommendation from me :D

[@r7u0s7]

"2 is not 5... unless you turn it upside down." hahaha

[@matthewbondi380]

I immediately made a mistake by assuming the corner 1, 3, 7, and 9 were givens like the center 5, overlooking that they could indeed be 5s and satisfy a condition. I was correct, but didn't notice my overreach until after I cleared the fog :(

[@IBAndreas]

I made exactly this same error by first placing the 5 and then placing 1 in 1,1 2 in 2,2 3 in 3,3 etc. However, even though I totally neglected the possibility of 5 being a digit the fog was indeed revealed now in every single box and made for an easier solve. I didnt even realize the error of my reasoning until AFTER solving and then watching Simons solve and scrolling down for this comment. I can totally understand the easy ratings on LMD. I would have rated this a 2 and just assumed my (lucky) solve path was correctly reasoned.

[@jasonmetcalfe4695]

Magic square logic at its finest I'm amazed Simon didn't spot it and go over it for people once again