Is This The Greatest Quadruple In Sudoku History?

[@kimberlypreston6204]

Watching Simon play sudoku is like watching a football game everyday where you know your favorite team is going to win! Great job, Simon!

[@BozoTheBear]

Well said! I often smile when Simon is stuck at the start, thinking oh man this is gonna be good.... because of course it is!

[@jonbrowne8334]

For the most composed man on the planet, loved Simon losing his shit with his phone! Hysterical 😂😂😂😂😂

[@DanielColborne]

Genuinely burst into laughter and got bizarre looks from my family.

[@Nimsshow]

He now knows my frustration at trying to solve anything beyond a basic sudoku.

[@brianj959]

I just love that his reaction to a buzzing phone is not to turn it off, but to throw it on the ground!

[@boman987]

This is why I tell my wife to keep our newborn infant away from me while solving my daily CtC puzzles. He’s at the stage where he buzzes too much and I can’t turn off the notifications. Edit: Doctor says buzzing is abnormal. On our way to a specialist. Apparently there is a way to turn it off.

[@DanielColborne]

@@boman987 Ativan

[@Sujisan4]

This has got to be one of the best puzzles ever showcased

[@MaximilianKoestler]

I find it amazing how Simon, during his explanation of the Phistomefel Ring, has intuitively arrived at using the term "bag". That is, in fact, an alternative mathematical term for a "multiset", and therefore exactly the correct word for describing multiple copies of the same digit.

[@amoswittenbergsmusings]

I think the use of 'bag' for 'multiset' stems from the world of software engineering. It is a very powerful concept - both in maths and in software. In the latter it is underused IMHO.

[@kevinwilde8246]

I believe I heard either Mark or Simon say something about the two of them being accountants, and if I'm correct about that, it isn't outside the realm of possibility that he does in fact know the term from some form of mathematics education.

[@danielwynalda6700]

@@kevinwilde8246 i believe simon was an investment banker. I think in the q&a for the last subscriber milestone he said that

[@AuntyAwesome]

@@danielwynalda6700 and also in one of their podcasts

[@jaydyer3999]

Watching this completely made my day! I always enjoy watching you solve puzzles, and seeing you do mine, especially as you followed the logic perfectly, was wonderful. Remarkably, the relation to Potatohead's puzzle was completely coincidental, and I was amazed when I watched your video of that one a few days ago. Another amazing puzzle with great logic of its own, that I admit I completely failed to solve myself.

[@alantaylor846]

Congratulations -- and many thanks - for creating this gem!

[@TheSonicPerson]

Yeah, I'm actually not the first person to discover the logic with the knight's moves that I used in my puzzle. Apparently that has been known since last summer but I discovered it completely independently. And I only discovered it because I was solving Palindrometers by Easily Amused, which had 1s go in the pedals ruling it out of the row 5 and column 5 cells in boxes 2 4 6 and 8, placing it in the central cell.

[@michaels4340]

Brilliant puzzle!!!

[@AussieJohnny]

Jay.....my dog, Louie, is very upset with you. Twice during Simon's solve I applauded and Louie jumped off of my lap and glared at me. What a fantastic sudoku. Congratulations.

[@jaydyer3999]

@@AussieJohnny Watching CTC with a dog on your lap sounds delightful, I'm jealous.

[@SeanWomack514]

I just want to share my appreciation to our illustrious hosts that they take the time and effort to prove things in slightly different ways than they have before. It not only helps new viewers, but it also entertains old viewers that have heard it before. Kudos!

[@ChrisParr]

I'd watch a video on "Explaining set theory: Evolving and improving methods in Cracking the Cryptic videos over time." 😀

[@nolans11]

I have watched Simon prove the Phistomel Ring dozens of times yet I still never skip it. Great solve Simon!!

[@tessabrisac7423]

Beautiful! From puzzle to puzzle, we are discovering new properties of the sudoku grid that slowly complete what we already learned about the rings and sets. In fact the sudoku grid has changed a lot (for me at least) in the last two years, from an amorphous stage to a very organized and structured field. Thanks to all setters, solvers and watchers for this, so amazing!

[@TheErPelu]

When I joined this channel during the 2020 pandemic I couldn't even expect someone could set a sudoku like this one. Absolutely mind-blowing. The level of sudoku setting being featured on the channel lately it's getting just ridiculous! Great great puzzle 🙂

[@ahouyearno]

I started watching because I wanted to learn about x-wings to solve a sudoku that had me stomped. I learned about concentric phistomephel rings, jellyfish, winged swordfish, colouring and uniqueness instead.

[@TheErPelu]

@@ahouyearno what a trip! :)

[@thorbjrnhellehaven5766]

2:06 Yes! The reaction by Clover was wonderful. I would like more of them.

[@jdogg5639]

If the derivation of the phistomefel ring already makes sense to you, with creating 2 sets and removing the overlap, just a quick note that the "expanded" ring can be derived in a slightly more straightforward way than Simon's way at 34:00 without having to think about duplicate counts. Instead just put rows 1,9 and boxes 4,6 into the first set, and columns 2,3,7,8 in the other.

[@rizka7945]

34:15 Alternative proof to this theorem which avoids confusing double counting of cells: - Blue set: columns 2, 3, 7 and 8 - Orange set: rows 1 and 9 and boxes 4 and 6 Remove overlapping cells and done!

[@amoswittenbergsmusings]

Beautiful! So clean.

[@slapusillydawg]

My face when listening to Simon's proof of the Phistomefel ring even though I've heard him explain it in multiple videos 😲

[@emo6577]

I think it’s a nice marker of how far I’ve come that now not only do I know the proof but I really understand the principles behind it!

[@jaeusa160]

Did your face do anything :O like when you realized you can rotate this proof 90 degrees as well?

[@bruresende]

Simon nervous because his phone won't stop buzzing but not picking it up at all... So relatable... I feel you, Simon... As always, brilliant puzzle, lovely break-in, genius turn around in the middle, really really enjoyable!

[@leojs5673]

I haven’t even watched the video yet, but just from the thumbnail, I feel pretty confident to answer “yes it is”

[@theryanmark]

CTC video is live! Step 1 talk about daily updates Step 2 queue maverick Step 3 let's get cracking Step 4 mention phistomefel ring and ponder if it's reliant to this puzzle Step 5 prove phistomefel ring Step 6 find a single digit that goes only one place outside of phistomefel ring Step 7 throw phone away Hahaha love it! 🤣🤣🤣

[@meme-ge8tq]

“It turns out experience at cracking hard puzzles DOES help!” The only part of this video I could’ve understood without Simon’s help

[@TheSonicPerson]

This was a wonderful puzzle that showcases logic very similar to the logic in my puzzle. It was such a joy to solve. Also thanks for mentioning me.

[@crazypomp927]

First we get a puzzle proving that an anti- knight Sudoku can have at most 1 digit not in the Phistomofel Ring and it has to go on the central cell. Now we get a puzzle proving the same thing for diagonal Sudoku. This is peak Sudoku time.

[@TheSonicPerson]

Yes, you can thank me for the antiknight discovery

[@Coyotek4]

This puzzle defeated me ... I needed to read this comment to see what I missed. [EDIT - OK, maybe I needed a bit more than this]

[@bcsmith]

“We’re basically done” 45 minutes later, and we’re done…

[@idova]

as soon as he said that, i said out loud 'oh boy you are asking for trouble'

[@PixieCinnanom]

Well, of course, with Sudoku ... that's a highly relevant number. ^.~

[@Vrplumber]

I don't know why I found it so funny, but I lost it when Simon tossed his phone across the room.

[@MaikaSHTsukiko]

i agree, I was eating and I almost choked. SO funny

[@margaretmcnarry4298]

I also found it funny, most likely because he is usually so composed, even when he gets excited about the beauty of the solve!

[@widgetb]

Every time Simon explains the Phistomefel Ring I get a little closer to understanding it well enough to independently think of it and apply it in sudoku! (And now my mind is blown by this expanded ring!!) Great puzzle and wonderful solve as always Simon.

[@mohamadsalemamaraya224]

i love the way u explain

[@pengwyn1]

Thoroughly engaging and immensely enjoyable, start to finish. Thank you, Simon (as always!) and Jay. Brilliant!

[@AdventCloudStrife]

Ever since I learned about SET and the Fistomephel (LOL sp?) ring, I wondered if one could construct puzzle that required two different SET considerations to solve. I'm glad to see it brought to life. Good stuff.

[@amoswittenbergsmusings]

Right letters, wrong spelling 🤣

[@TheSonicPerson]

It’s Phistomefel

[@dkosmari]

At some point we might need multiple layers of coloring in the app, so we can switch between different set colorings.

[@jleclanche]

@@amoswittenbergsmusings it’s one set of the letters efhilmopst in any order with the letter e double counted.

[@crystalgehrt8861]

Simon, the reason we have all these amazing puzzles to solve/watch is because you got the crazy idea to start posting sudoku puzzles and your personality is such that people can't help but to love watching you solve them. You're so excited and amazed every time. And because of the popularity you have brought to the channel, more people are seeing great puzzles and setting even greater ones. It has all snowballed to a wonderful community full of brilliant setters and enthusiastic viewers/solvers, and the puzzles only get better. Thank you for making sudoku the brilliant, mind bending, fun game it has become.

[@sjoerdng]

First time i saw this explanation of the ring. How elegant.

[@shawnward6607]

"I cannot concentrate with this buzzing" Throws phone away "there I got rid of it" This is my dream... just ignore my cell and toss it away... maybe some day. Thanks Simon!

[@tessabrisac7423]

Not often do we happen to see Simon’s cold rages on the channel, but it seems to be an outstanding feature behind the scene!

[@shawnward6607]

@@tessabrisac7423 I know its odd/crazy... i just adore simons reactions when solving... it is like me when i am doing reall instensive grading work or storm drain work... I get crass and just say... leave me alone for the next 10 minutes!!!

[@boman987]

I just turn off all vibrations on my phone. Nothing is that important.

[@goliathcleric]

I take one look at this puzzle and I immediately think, "Ah, yes. Phistomefel. Even in the puzzles he doesn't create, the devil appears."

[@andrewsparkes6275]

Ironically, I filled in the 12345s first, and noticed the low-high thing first, so started filling in the colors as 1-5 being yellow and 6-9 being red. That definitely helped me far more than the ring!

[@inspiringsand123]

Rules: 03:22 Let's Get Cracking: 04:58 Most popular number, 'high/low'-ness, colour, box and parity this video: One (153 mentions) Low (9 mentions) Orange (41 mentions) Box 1 (3 mentions) Even (4 mentions) What about this video's Top Tier Simarkisms?! Maverick: 2x (04:55, 05:03) Knowledge Bomb: 1x (07:46) Three In the Corner: 1x (44:08) ​Scooby-Doo: 1x (26:26) And how about this video's Simarkisms?! Phistomefel: 26x (08:39, 09:20, 09:30, 09:32, 10:52, 10:59, 11:21, 11:30, 14:47, 18:24, 18:54, 19:06, 20:41, 20:52, 23:42, 32:52, 33:19, 36:16, 36:58, 37:03, 37:16, 40:49, 51:56, 52:18, 52:26, 52:26) Sorry: 8x (09:25, 11:24, 21:44, 29:20, 30:14, 31:16, 34:20, 43:17) Hang On: 7x (15:07, 22:56, 33:24, 33:24, 34:37, 44:23, 46:12) Good Grief: 5x (06:39, 11:04, 11:22, 22:02, 47:54) Beautiful: 5x (10:02, 11:06, 11:19, 18:08, 45:34) Magnificent: 5x (39:46, 39:49, 44:15, 44:17, 51:06) Goodness: 4x (11:14, 41:52, 49:17, 50:59) Stuck: 4x (09:20, 21:44, 25:39, 44:58) Gorgeous: 4x (11:10, 45:43, 50:23, 50:23) By Sudoku: 4x (25:50, 40:05, 40:19, 47:05) Naked Single: 3x (29:19, 39:37, 44:25) Schrödinger Cell: 3x (16:45, 16:47, 52:01) I've Got It!: 3x (10:40, 10:44, 47:35) Clever: 2x (23:22, 51:24) Brilliant: 2x (02:29, 51:02) Shouting: 2x (05:09, 31:21) In Fact: 2x (01:42, 42:31) Obviously: 2x (04:41, 19:16) What on Earth: 1x (27:26) Out of Nowhere: 1x (29:11) In the Spotlight: 1x (44:11) Horrible Feeling: 1x (27:45) Fascinating: 1x (25:35) Extraordinary: 1x (51:13) Ridiculous: 1x (38:19) Deadly Pattern: 1x (41:58) Take a Bow: 1x (51:10) Come on Simon: 1x (29:52) My Phone is Buzzing: 1x (11:22) Doesn't get a Song: 1x (40:34) FAQ: Q1: What is a Simarkism? A1: A Simarkism is something that Simon and Mark typically or frequently say. Q2: How do you do this so fast? A2: I'm not made of flesh and blood, but of sand ... Q3: Why don't you include 'XX' and 'YY'? A3: Probably it's already on the list ('Scooby-Doo' for example), but not mentioned in this video. But if you think it's not, tell me what you'd like me to include and there's a good chance I'll add it! Q4: You missed 'XX' at 'YY:ZZ'! A4: That could very well be the case! Human speech is hard to understand for computers like me, especially British sometimes! Point out the ones that I missed and maybe I'll learn! Q5: Could you turn these statistics into videos? A5: I've been playing around with the idea and I'm open to input as to what people would like to see. Let me know if you are interested in this and/or have suggestions.

[@the-yw1cm]

26 mentions of "Phistomefel", I know this'll be a treat

[@cooldude8475]

phistomefel at 5:10

[@flwi]

@@cooldude8475 they use the youtube autogenerated subtitles to find the phrases. (I did the same thing recently because I was interested in it and needed a little coding challenge) Apparently the youtube algorithm understood "the victim fell at me" 😂

[@cooldude8475]

@@flwi oh I know, I only pointed it out because in Q&A they said that it would be useful.

[@inspiringsand123]

@@flwi If you want a little coding challenge, then try to match 'Phistomefel' consistently! Check the subtitles at all of the timestamps that I detected ;) @cool dude: thanks!

[@dubtak4976]

I was expecting a previously undiscovered third ring to be necessary at the end. Like a horror movie jump scare.

[@StefanPettersson]

I agree with Simon. The setter videos are very interesting. Keep 'em coming!

[@lizmartin1930]

Simon, as always, continues to amuse and entertain. Phone throwing, excitement over simple deductions, and appreciation for brilliant setting: all things I would expect of a video from him. I love CTC and have finally fallen back in love with sudoku, even getting my kids in on the JSS pack. Thank you for the videos and the work you put into them.

[@alessandrobuzzin7982]

20:23 most epic "act of valor ever". Well done, mr Simon :)

[@brucejones533]

Wonderful battle! Congratulations on your victory. Loved it.

[@nicoles7652]

I love the little self-joking (deprecating but not) moments like at 7 minutes "it's practically done!... but maybe not." It gives such an airy vibe which makes it very approachable to watch these videos for someone like me who'd never manage to solve puzzles like this in a million years.

[@Qazqi]

Stealing a trick from Rangsk, when you explain SET that involves double counting a digit, you can avoid the double counting by interleaving eliminations. For example, in the expanded ring, you can highlight all four corners in blue as you did and then rows 1 and 9 in orange. Instead of doing all 4 orange sets immediately, do orange-blue eliminations on those two rows first. The corners end up as white. Then you add columns 1 and 9 and the corners naturally turn orange without double counting even appearing. That's the main point I find people have trouble with when understanding these SET tricks, so it should hopefully make the explanation more accessible when you don't have an alternate proof like you do for regular Phistomefel.

[@bool.]

The expanded Phistomefel rings can also be proven without double-counting. For the fully expanded version (not sure if these have specific names), highlight C2, C3, C7 and C8 in blue, and then R1, R9, B4 and B6 in orange. Cancel as normal. For the middle ring, you can have C1, C3, C7 and C9 in orange, and then R2, R8, B4 and B6 in blue.

[@neilturton1427]

Sir, take a bow! This one took me several hours and you managed to solve it in under one. I'm impressed! I'm also grateful that you walked us through the logic. It is beautiful.

[@elainedenning]

I vote for you grabbing your guitar and a mic, belting out your best rendition of "That's three in the corner", and then edit it in at the appropriate moment at every available opportunity!

[@balkthor]

Man, I wish I had my own personal branding where a Devil was stamped on all my work at the office. Lucky Phistomofel!!!

[@garrettsmith9788]

Mark gets a call. Hold on a minute, it is Simon. Simon gets call and throws the phone across the room.

[@th.nd.r]

Great puzzle and solve once again!!! Jay Dyer, another apparently incredible setter who deserves more channel features! How did they even come up with such a cool concept??? What I find so cool about that is that it’s the exact OPPOSITE quadruple than what you might get in the corners in, for instance, some diagonal arrow sudokus. Very cool

[@TheFreeBro]

Just got into the GAS puzzles from discord and I keep finding myself saying “What am I supposed to appreciate here...” when I get stuck

[@pietvanvliet1987]

Would like to see Phistomefel do a variant on 'setter reacts' to this one. And if you would excuse me, I need to take my hat off to mr. Dyer now.

[@longwaytotipperary]

Loved Clover's video! Looking forward to watching this - it looks great! Also will watch when Simon and Mark host the author's panel!

[@amoswittenbergsmusings]

I'll basically watch anything these guys put out - I know that nothing will hurt anyone. They can read the phonebook for my part.

[@longwaytotipperary]

@@amoswittenbergsmusings Same, Amos, same. 😊

[@GarfieldConnolly]

Another wonderful hour in your company. I couldn't do the hard bits, but I saw some of the easier Sudoku numbers earlier :)

[@joeloedeman5160]

It would be fun to see a stream of a setters round table. Get to know a few, maybe have each bring a favorite setters trick or two. Just a thought.

[@andrewgrant6516]

If there is some sort of Nobel prize for sudoku, I would like to nominate Jay for it. Standing on the shoulders of giants, sure, but blimey what a view!

[@zacharyn5520]

This puzzle is genius! So glad I got to see this solve. Great job!!

[@nickburton5871]

Does anyone else find themselves saying, in their best somewhat incredulous Simon voice "Oh! Where does the 3 go in line 4...?!" ? Love the videos, Simon!

[@gregind01]

20:15 "I am going to throw my phone out of the window in a minute!" buzz 🤣🤣🤣

[@tricia1072012]

"For pure pleasure let's not put a five in orange." This moment sums up everything I love about this channel.

[@gc2009able]

Aaahhhhh! I was stuck for so long with the deadly patterns at the end and I finally had to watch the rest of the video and then Simon pointed out the clue outside the puzzle, which I had *completely* forgotten about! I feel so silly.

[@Stuartdouglas19]

Incredble trick there. so not just one SET but two - first time I think I`ve seen that. I`m sure other setters are now getting lots of ideas in their head to expand on this

[@unoacaso105]

It's very simple: I see a satanic figure in the thumbnail, I click the video.

[@BozoTheBear]

Very very very nice puzzle! I needed quite a few hints, but was so blown away by the famous quadruple that I coloured them with all 9 colours!

[@Zardox2]

Been waiting all day until I could settle in with a beer, and some snacks! I actually opened the puzzle, and though i would laugh at my audacity... but... I actually was able to find a bit of a start! 😳 Ok... couldn't work my way through it... but a few months ago I would have fainted dead away at the mere THOUGHT of any attempt! Also... a resounding YES for more reaction/commentary videos from setters. I really enjoyed Clover's explanation of her thought process for the break-in! Thanks CTC... This channel ROCKS! Edit: WOW! Now we know why it was Rings... Plural! Brilliant puzzle, Jay!

[@wade_23]

20:19 and just like that Simon YEETed the phone across the room lmao

[@angelmay27]

I love your proof of the Phistomefel ring! Makes so much sense!

[@harkelin]

Thank you for this video! Looking forward to it - lets get cracking! ×stuffs face full of popcorn×

[@Steevscool]

I was trying to reach you about you car's extended warranty, but you chucked the phone.

[@denniswieduwilt4546]

I wanna see a best-of moments and reactions from CTC, in and during sudokus

[@jamesheath2173]

Broke the puzzle. Started over. Broke it again. I can't figure out what I am doing wrong. Time to watch the video, I guess.

[@57thorns]

Quorum means the least number of voters needed in an assembly. It really makes sense for those properties used. And having one low ring for the normal Mephistomefel, and a high ring for the expanded ring was genius. Through it all it was a minimal use of "voters" to fill in the grid, and using the diagonal twice was another great move. Loved watching the solve, it did not _feel_ that hard with Simon leading me through it, but I wonder if I could have made it through on my own.

[@solfeinberg437]

Wow, I really like Jay Dyer's puzzles now. Came here from another CTC Jay Dyer. Clover talks about what makes a puzzle interesting and enjoyable, the relation between work and reward. These are incredibly interesting. They yield lots of fruit - using both sets of Phistomofel rings. And rings being in the title. So many quintuples, quadruples, triples, and pairs (eventually). Good puzzles, as Clover says, make you feel really smart. I got a couple of ideas from Simon. Literally all I heard him say was rings (plural) and knew - okay, let's look at the other one. This style of logic really suits me. I feel totally brilliant!

[@andrewjanssen8663]

So frustrating when Simon used the 2-4-6 triple in box 4 to eliminate a 6 from r3c2 and then utterly failed to see that the 7-8-9 triple next to it forced a 6 into r3c1.

[@jeffreytennant6980]

Absolutely positively magnificent logic

[@laszloliptak611]

Beautiful puzzle. For the second version of the Phistomefel ring it is not necessary to go over the proof again (especially a different one: instead pick rows 1 and 9 and boxes 4 and 6 to get four sets of 1 through 9, then pick columns 2,3,7,8 for the other, then delete common elements). It is sufficient to start from Phistomefel's identity, and swap rows 1 and 3, rows 7 and 9, columns 1 and 3, and columns 7 and 9. One can obtain quite a few other versions by swapping different rows/columns.

[@Stephen-Fox]

Me: "OK, I get to this point but I don't have the foggiest of where to go from here" Simon, 24 minutes in and far before I got stuck "Why is it called quorum rings, that concerns me" Me: "...Oh. _solves puzzle_"

[@andilee3537]

wow. What a stunner. I don't think I've ever solved either a harder or more beautifully constructed puzzle as that. Absolute mindblower to find the quad in the central square.

[@andilee3537]

Watched the video and so enjoyed what Simon did - but I did it a completely different way - finding the middle square quad rather than the outer one - which didn't use the second Phistomefel, and only needed the first standard ring

[@martinepstein9826]

Phistomephel AND a Phistomephel variant! And both use the same ingenious logic with the diagonals. That's wild. All this SET reminded me of a puzzle Mathologer posted recently. It has an elegant solution using an aforementioned technique if anyone wants to give it a try :) Puzzle: You have a rectangular grid of cells with an even number of cells on each side. Each cell is given one of 4 colors in such a way that every 2x2 region contains 1 of each color. Prove that the 4 corners of the grid are all different colors.

[@andrewgrant6516]

The third Phistomephel ring is around the inside of box 5, and there is a maximum of one digit that can't be in it, which also has to go in the centre square.

[@tessabrisac7423]

😹… and same thing in every other box, and we have 12 rings altogether! 😂

[@dwarfmunder4860]

Am I the only one who keeps expecting that when Simon does the "three in the corner", he'll pause slightly between "spot" and "light"? But then I always expect Mark to sign off with "Bye for now and bifurcate!"

[@INGALIL]

This is probably one of my favs on the channel. Amazing puzzle, and a what a great solve Simon!

[@lmelior]

Loved that one! I needed a bit of help twice, first at the break-in and then eliminating the 5 out of the corners. But still, it was so immensely satisfying creating all those different triples and quadruples, eliminating possibilities from the diagonals, and finally figuring out the little killer to resolve it. Great puzzle and super enjoyable solve as always!

[@iwatchTheYogscast2]

Gotta say I really love how the ending isn't just ok now the puzzle is basically solved, just gotta fill in the didgets, but that there's actual substance to it with the 29 clue

[@donaldsnyder1543]

Wow nice puzzle, out of my league but interesting none the less. Also showcases Simon Variant Sudoku , which is always a bonus. (3 you know where 😁)

[@jaydyer3999]

When I was watching the video and realized Simon was going to get to sing eventually, I couldn't help but smile.

[@hauntedmasc]

alas, i was very hopeful we'd be seeing all 3 of the phistomefel variations; i do think the solve is slightly easier when the middle ring is also considered.

[@jaydyer3999]

I had a look into that myself, and found that the middle ring can be used for a few eliminations (e.g. by realising there needs to be a 1 in one of the corners of the middle ring). All of those eliminations follow easily from the logic in the outer ring though, so it's very easy to miss. If someone does come up with a puzzle where all three rings are required though, that'd be pretty amazing.

[@wynq]

@@jaydyer3999 I keep hoping someone can set up a triple ring as well. It needs to be titled "Insetption" (in-set-ption), because it is a set ring w/in a set ring w/in a set ring.

[@AllenBaranov]

I would love to have a "Mark reacts to Simon's solve" video :)

[@thorbjrnhellehaven5766]

34:33 to fix the double counting, and make it general: Any two rows, and two columns, with overlap in four different boxes: Make them orange and add red for double (You have 4 sets of 1 to 9, in orange + red) Make four boxes with double counting blue (You have 4 sets of 1 to 9 in blue) Remove red+blue from cells, leaving irange behind (Orange = blue) Remove orange+blue cells (Still: orange = blue) This generalized approach can be used for many different patterns, including both paterns in this solve.

[@jonasbranstrom5323]

You absolutely blew my mind Simon, thank you for that! And thank you for the marvellous explanation!

[@CuratedPile]

Great puzzle! I happened across the 3rd ring, between the other 2, the 4 corner cells in the 4 corner boxes are the same digits as the center cells in the corner boxes plus the middle 3 cells in rows/columns 2 and 8. This came up once I noticed that the 4s in boxes 2,4,6 and 8 were all in that middle row/column. I used this to set some digits by coloring and removing matched digits from both colors.

[@ozlich]

Sometimes you solve alongside Simon. Other times, you're just a passenger. Brilliant.

[@mohamadsalemamaraya224]

i love ur puzzles

[@maximehedde3648]

Magnificent puzzle indeed !

[@AllenBaranov]

At 49:50 the easiest way to finish is to see that c8,r6 can not be a 9 because minimising the other numbers would still add to 30. Simon ignores that and finds some arbitrary number elsewhere in the grid and does a complex calculation that results in the same outcome. Because it is Simon.

[@shashipancholi]

quick way to highlight the expanded Phistomefel ring: - columns 2, 3, 7 & 8 are four complete sets (blue group) - rows 1, 3, 4, 5 & 9 are five complete sets BUT box 5 can be removed to make it four complete sets (orange group) - blue and orange groups are identical - remove any overlapping cells from both blue and orange groups - remaining blue and orange groups are still identical

[@kordellcurl7559]

There’s also something with the 11/10/11 that makes it that you can know where the 4s and the 5 go because if you put it in the bottom of the L(the single cell not the 3 length cells) you can say that it is a 123.

[@Coyotek4]

Every time I feel like I got a bead on these puzzles, something like this comes along and kicks my ***. Spent 20 minutes on it, got nowhere, quit, came back, spent 20 more minutes, gave up, checked the comments (which gave the amazing rule involving Phisto with X-Sudokus), went back, made progress, got stuck AGAIN, gave up and watched the video ... and saw that I needed ANOTHER variation of Phisto to finish. (From the 36:52 point of the video, I was able to make it.) Too tough for me.

[@tim_hutton]

There's a nicer way to explain the expanded Phistomefel ring: highlight columns 2, 3, 7 and 8 in one color, then rows 1 and 9 and boxes 4 and 6 in another color. No double-counting needed.

[@THEPELADOMASTER]

Schrodinger's cat isn't alive and dead at the same time forever, it's only until you check which one is it. The same as a sudoku cell that hasn't got a digit in it. So technically, a sudoku is composed of 81 schrodinger cells that are simultaneously 1 2 3 4 5 6 7 8 and 9, that collapse into one unique sudoku solution when you solve the puzzle.

[@Swisswavey]

That took me ages and I feel like I've been beaten up. It's too late to watch the video now but I'm betting Simon found a lot of things much more easily than I did. I'll find out tomorrow...

[@jdyerjdyer]

This one was not easy. It started off very easy, but runs you into a brick wall pretty quickly. Then you go, "Aha!" seeing that the four cell 22 cage is forced. Then you drive around a bit only to run into a boulder. Then you go "Aha!" again realizing that the three cell 22 cage is forced. Now you can drive your beat up, smoking ride home feeling like you cheated death! :) See the video for the two "Aha!" moments. Simon found them. I found the first one myself, but had to get help in seeing the expanded ring's implications. Very nice trick! Thanks for a fun, beat your head against the wall, afternoon! :)

[@allikin75]

Am I the only one imagining scrabble tiles with numbers on them in scrabble bags when Simon explains the Phisto ring? :D

[@apiyo_puzzles]

Wonderful stuff!

[@Whothewaynecares]

It's pretty fascinating to me that i witnessed a pro learning something new in a previous puzzle AND apply that knowledge on this one. I was pretty sure it was a one time discovery when he did that on the other puzzle.

[@fulltimeslackerii8229]

so now not only in a knights move sudoku can only 1 digit not be in the ring, but now in a diagonal sudokus too! this is an amazing expansion!

[@Sullrosh]

The ring can actually be used with any two rows and 2 columns that don't cross the box 5

[@RichSmith77]

Isn't it any two rows and any two columns that cross in four different boxes? I don't think there's anything special about box 5.

[@Roblilley999]

That moustache is making you a rebel, throwing your phone like that

[@derekwalsh1973]

Every time Simon explains the Phistomofel Ring I promise myself I will skip past it next time......but I never do

[@bruresende]

I lie to myself like this every single time too... It's just not possible...

[@tessabrisac7423]

This time, it was indeed minimum and crystal clear.