The Foggy Killer Sudoku

[@Visumation]

Hi Simon and all the the CTC testers. Thanks a lot for giving my puzzle a go on the channel. Really appreciated.

[@steve470]

It's a really good puzzle - you definitely earned the feature.

[@Visumation]

@@steve470thnaks❤

[@cooperleher10]

I loved your puzzle!

[@Anne_Mahoney]

Nice puzzle: hope to see more of yours!

[@chiarra644]

OMG!!!! I hope he emails back what she said. That was the sweetest proposal and omg omg omg omg!!!!!!!!!!

[@WorldsPhamous]

I paused the video to start looking at the comments

[@Ardalambdion]

Simon is right about one thing, the world needs more love.

[@longwaytotipperary]

Amen!!!

[@yadiracamacho499]

That poem was so beautiful, good luck Michael!

[@masonweddle6243]

Absolutely beautiful. I'm on the edge of my seat! I need an answer!

[@Alex_Meadows]

If the question is "What's for dinner?" I'm going to be very upset. Good luck, Michael!

[@MeriaDuck]

❤

[@longwaytotipperary]

😄😊

[@RickyRatte]

Imagine if this wasn't written by any Michael, but just by a guy who hoped he'd troll at least one pair of Michael and Jenna

[@xerodeus2337]

Wait is this Simon back now and not a long ago previously recorded video? Seems like it so glad he's okay!

[@TheMeanderingduck6]

I'm out of the loop. I've only seen the comments on the past few videos about them being prerecorded. What happened to Simon?

[@xandermouser2216]

He was always fine he was just in new york

[@xerodeus2337]

@@xandermouser2216 a lot of us must’ve missed that because one video he said he was starting to not feel well and wasn’t sure he was gonna make it through the video and then the next few days after that we’re all pre-recorded videos from sometime ago

[@arandamei2189]

@@xandermouser2216 Not via American Airlines this time we hope!

[@leeuwevdh]

@@xandermouser2216 where did they say this?

[@RoderickEtheria]

27:04 Simon, just look at the cages already in view. The dashed line always goes into any cage on its edges or corners. You have bent cages already visible showing how it would look.

[@grahamania]

00:48:40 for me. Wonderful puzzle. Love how fog and cages can work together with the clue position! Kind comment.

[@Jigkuro]

Done in 17:01 which makes me worry what Simon missed. Guess it's going to be a 'yelling at screen' day. 😂

[@longwaytotipperary]

OMG!!! What a wonderful poem from Michael to Jenna Marie!!! And to have Simon with the dulcet tone voice read it to her!!! I hope we will hear the wonderful answer soon!! Also - great to have a foggy puzzle and Simon back live and well!!! Oh and happy birthday Michael!!

[@davidrattner9]

Great to see you my friend. Happy holidays. Hope you have been well❤. The poem was exquisite indeed and Simon certainly did it justice😊😊 Simon with fog is a match made in heaven. Splendid to have him back for us "live" 😊😀😁

[@longwaytotipperary]

@ Also hope you are well and have happy holidays!! ❤️❤️❤️

[@Gnarlf]

Normaly the solve is the most exciting part of the video. Today however 😍

[@tremkl]

Well, I ALMOST solved that on my own. I got stuck, pulled the video to what I was stuck on. Simon paused the video and said “You can get this square”. I left it paused until I solved that square, then solved the rest of the puzzle on my own. Simon just told me where to look. 😂😂😂

[@Antiknight]

Great break-in and lovely deductions in the mid-solve! Loved it!

[@davidrattner9]

Always a joy to see you write about puzzles on here. 😀

[@Antiknight]

@ Thanks David! It’s always a joy to see you in the puzzling world.

[@ChrisStavros]

This is a very nice puzzle for novice level solvers like myself, it takes you through the puzzle step by step, keeping your eyes on what's relevant for solving the next part.

[@MarkBennet10001]

One digit/value is twice the other could be technically more correct for a black dot, as well as easier to understand. eg in a 0-8 puzzle with modifiers it would be possible to have a 0:0 dot.

[@MeriaDuck]

Ow dear that would be trippy 😂

[@netkissa]

I did it! I did it! I usually can't solve these puzzles but this one I did! I did watch the begining to get the hang of the puzzle. But not far enough to have any actual numbers placed on it.

[@zadrik1337]

I loved the Christmas Three song.

[@TheokeS85]

27:08 over the years Simon has made this “assumption” many times. And he’s never been wrong. However he has dismissed it every time.🤔 Never change Simon, never change.

[@leefisher6366]

Welcome back to full health, Simon. I just thought of a devilish idea for fog of war creators: the idea of having a fully fogged out grid, where the first digit HAS to be worked out by trial and error, but you can then complete the Sudoku... no matter where that digit was. (This would have to be normal fog, of course). I imagine the grid would have to have a lot of clues all over the place to cover all contingencies.

[@Anne_Mahoney]

That's like one of those "check your skill level" puzzles that were popular a couple of years ago, where you can choose whatever you want for one particular square (say, r5c5), and you're told some values make it easier and some harder. It would be neat to combine that with fog. (Hmmm: and a very smart rat?)

[@leefisher6366]

@@Anne_Mahoney I like the way you're Finkzing...

[@titusadduxas]

1:08:09 - Brilliant puzzle!

[@brspies]

Lovely puzzle. Really masterful use of so-called "cage furniture" to aid deductions. Even the clues that seemed uncomfortable unrestricted ended up giving me useful information once I had the sense to look them in the eyes.

[@Xiuhtec]

32:15 solve for me, love fog puzzles because it's much clearer to me where to look when, stopping me from my usual tilting at wild geese on the wrong end of the grid.

[@EllaABo]

Welcome back, Simon!

[@HunterJE]

18:13 Oh no, the return of Simon's most dangerous pencil-marking habit of just deleting all the pencil marks and re-marking with all the options, losing useful narrowing of options previously done

[@PassionPopsicle]

He fixes it at 20:14 for anyone screaming 😂

[@brianj959]

Yes, he does this a bit too often for my comfort too, with corner pencil marks in particular; although, he doesn’t wipe out centre pencil marks too often just to replace them again with more centre pencil marks! His ‘grid memory’ is often surprisingly good even when he does this - although he does occasionally losing efficiency, particularly given his scattergun approach to basic sudoku in general. For a beginner to intermediate solver (like me), it is not a habit I would recommend we emulate. :)

[@jaeusa160]

@27:00 It's not an assumption though. You can see what a 3-cell bent cage looks like in box 9. Clearing fog never adds details to an already-revealed cell, revealed cells contain all their visible info. So I feel it is a disservice to your information to consider this r6c5 could be uncaged when you have the visible information that it is 100% caged. To me, this is no different than declaring r5c5 and r6c6 to be caged cells, it is based on the same visible information and is no less valid.

[@jvcm8649]

83:28.. spaced out a bit in the middle and it was pretty difficult at some points too.. but it was very satisfying to solve!! loved it

[@A_CC_K]

Fog of war is my favourite puzzle type.

[@MarkBennet10001]

I remember solving this - it is beautifully conceived.

[@Paolo_De_Leva]

_"Dinamic fog"_ is not an appropriate way to describe the innovative _"fog of where"_ introduced by *James Sinclair.* Standard fog is not static. It moves away very quickly when you place correct digits, and fog of where does the same. The only difference is where it lifts, not how swiftly it reacts. I would call it *smart* or *selective* or *remotely controlled* smog.

[@stuffedlegoguy461]

22:29 for me! Was nervous by the semi-long episode length, but got it done relatively smoothly!

[@sophieliu8735]

I had so much fun with this one! The cage shenanigans felt so stupid in truly the best possible way

[@ashleyandreoni8023]

Never been so early! Love your channel!

[@Tokikosworld]

@45:26 Why can't the bottom digit not be a 2? Or why can't the middle box digit not be a 7? I can't see it at all!

[@BijickY]

At First I was also surprised. But there‘s already a 7 in the middle box. Just Sudoku. 😊

[@1specified]

26:48 this is true; you can see it in the bottom right

[@MaierFlorian]

Finally a Christmas Three again ♥

[@AWanderingSwordsman]

39:05 for me. That was some pretty cool logic in the top left. I feel like I dialed in on what it meant decently fast. EDIT: Also I wonder what the intended path was later on. I was able to use uniqueness to solve the 2 15 cages (they can't both be 6+9 because they'd make a deadly pair and none of these rules can break a deadly pair). Man I love when uniqueness lets me skip steps. It feels like accessing a late game area in a video game before you are supposed to get there and grabbing some massive xp or late game gear.

[@st3phgr1ce]

Glad to have you back! ❤ That 1 in box 8 was screaming for a very, very long time 😂😅

[@Kirbyfan87827]

Finished in 42:43 with help from the video. Pretty good!

[@A_CC_K]

You know the video is going amazing when Simon is colouring!

[@gregind01]

Good to see Simon back again, not just prerecorded! 👍

[@eddieharwood7788]

What a fabulous puzzle.

[@constanza1648]

I don't know if it was intended or not, but I kept making deductions here and there in the puzzle without a logical path, maybe I didn't think hard enough about the new information I had or I missed some clever and deep deductions that make the puzzle go for a less bumpy path. Nonetheless, I ended up in 29:22, good time for me.

[@drummerjrc]

If the rules included the statement, “This puzzle has a unique solution,” would you allow yourself to use uniqueness to disambiguate?

[@CharlesGregory]

I'd love to see a Q&A style interview with Simon and Mark where they ponder questions like this!

[@stangerrits6712]

I remember doing a puzzle once where it was explicitly stated in the rules. Not only the fact that it had a unique solution, but that you had to use it to be able to solve the puzzle. So if it's stated like that, yes I would use it. Otherwise I would assume it has a unique solution but not use it.

[@stevieinselby]

Yes, and it has been done. There was a puzzle that explicitly required you to use uniqueness to solve it - "Killed them with Uniqueness" by AFrayedKnot on 27 June 2021 - which was an absolutely fantastic puzzle, one of those ones that just has you laughing your head off as you solve it, well worth checking out.

[@franzelmagetower]

Loved that puzzle. Never seen a more interesting column 3! 37:11 here.

[@philipjames1599]

39 minutes for me. Really great video. Love fog of war

[@srwapo]

44:21, got stuck a lot of times. That 8 cage in box 7 did a lot of work that took me forever to see.

[@wanderlustwarrior]

Happy birthday, Michael, and congrats on your daughter! I hope she says yes!! 26:32 for me.

[@PassionPopsicle]

Early today - and a fog of war no less, what a treat.

[@piarittersporn]

Brilliant puzzle.

[@ElysaraCh]

"we have never published a puzzle that has two solutions" I'm pretty sure it's happened at least once, but it wasn't due to uniqueness issues

[@humbertoseghetto5218]

43:15 I would never shout about that, Simon. Maaaybe about the 3-4 pair in the same columm, but only a little

[@awilliams1701]

it's been a while since I watched CTC. I did see the original "dynamic fog" as you called it. Sounds like there have been more.

[@rhparvez]

Same here, started watching again a week ago. Enjoying these dynamic fogs. There's a video titled like "Breakthrough in Fog" 3 weeks ago, it all started there.

[@euphud]

I'm waiting for Judah Maca-three to make an appearance next week. Please make that happen!

[@levb258]

Such a fun puzzle!

[@hinkovanderboom9256]

To be honest, sometimes i don't see the conclusion he makes. Why the 1 on the first row above the 5? At 24:39 oh now i see it because of the 3 in the top row.

[@zobososhizion6478]

00:45:33

[@paulparker9593]

A warning to those solving in Dark Mode - the dot colours are inverted!

[@keoshine]

63:59 because it took me *way* too long to realize that the digit in R4C1 had to be in the 8 cage in box 7..

[@Rach881101]

41:18 for me. Nice puzzle!

[@ThePhenomBot]

Is simon back? Or is it one more pre recorded video?

[@DiederikdeVries-f9t]

My tired brain took 83:03 to solve this.. But hey, it's a solve!

[@PathOfShrines]

Nice puzzle. 37:11

[@mahtabhashemi950]

Awesome!

[@michaelmatter1222]

Très bien 👌

[@fuxpremier]

40:21 for my time. Good use of the fog to interact with the geometry of the killer cages. This gave rise to nice logic. Pleasant puzzle.

[@zoltankalovics7910]

how many people were completely thrown off by the "clue" being inside "" in the killer rules? :)

[@Roblilley999]

You didn't tick at the end

[@TurquoizeGoldscraper]

36:03 for me.

[@AndreAy1975]

Solved it without help from the video.

[@boomergames8094]

O Christmas 3!

[@LednacekZ]

20:55 why does he assume that the 16 extends into box9? those could have been 2 different cages. There is no rule that says that cages cannot overlap. Either he is working with a different set of rules than us or he is making a giant leap of faith here.

[@RichSmith77]

It isn't stated, but isn't it a standard rule that cages don't overlap? It's like cage furniture. It's only convention that means a cage boundary in one cell means the cell on the other side of the boundary isn't in the same cage that has done a tight u-turn. By similar convention, cages never overlap.

[@LillaJag]

As far as I know a cage in a killer sudoku can never overlapp with a other cage. It's common knowledge if you have solved a killer sudoku before!

[@NetMaple]

There's also no rule saying the cages CAN overlap.

[@LednacekZ]

@@NetMaple true but fog sudoku tend to have quite weird rules.

[@NetMaple]

@@LednacekZ sure, but I was more trying to indicate that assuming a puzzle feature (that isn't ubiquitous) because the rules don't expressly prevent it is a weird way to approach this. Like the rules also don't say the cage clues are in base 10, but I wouldn't randomly assume they could possibly be in base 8

[@Epic-1224]

18 minutes for me

[@robertcousins2274]

35:33 for me