The Hardest Sudoku Of Them All: Simon Vs Phistomefel Live

Simon attempted the new Phistomefel puzzle in a livestream. It's fair to say this is one of the most extraordinary sudokus ever made.

You can find the puzzle here with an example of how it works:

You can play the puzzle here:

Rules:
Every digit from 1 to 9 has to appear once in every row, column and region.
The regions first need to be determined. Every region is a set of nine orthogonally connected cells.
A digit in a circle indicates the number of borders between regions it sees in its row and column. Note that the edge of the grid does not count toward this total.
Remark: There is no negative constraint regarding the circle, i.e. there can be uncircled cells containing a digit that equals the number of edges seen in the respective row and column.

Patrons of the channel on Patreon can watch a video where Mark solves the example puzzle from the logic masters link above right now.

*** Our Patreon - The Best Sudoku Club In The World ***
You can join us on Patreon for as little as $2/month and access a lot of extra content. Today Mark has added his solve of the example from Phistomefel's new puzzle! This will give you an idea of what Simon will face tomorrow.

▶ SUDOKU PAD - Our New App ◀
You can now input your own classic sudoku puzzles into our software using our new App! The app also comes with 12 handmade puzzles from us and we're also releasing occasional bonus puzzles too. Get SudokuPad at these links:

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[sushirunner]

I just had the vision of Simon sitting in a huge stadium that is packed with people, there are massive screens everywhere and he is doing a live solve. The crowd is chanting "bobbins! bobbins! bobbins!" and sings along whenever there's a "3 in the corner, ..." :-D

[wesilvermagnus]

I’d love to see livestreams of extremely hard puzzles like this become a semi-regular thing!

[timduffy]

The biggest mistake made during this solve was at 2:02:21. Simon says "When judged by a jury of [Phistomefel's] peers..."
However, it should be obvious that Phistomefel has no peers

[Jodawo]

In the beginning it's very slow. Most of it is Simon getting his head around the constraint. It is like Simon is teaching himself how to use the new constraint just as the setter probably did when he came up with the concept. It does increase in speed and in enjoyment as we go along. For as difficult of a puzzle this is Simon did a very good job keeping us on track. I think that is the beauty of seeing Simon's solves. They are not only enjoyable but we go along the journey with him. It's exactly what a good movie would do.

[gd_]

You should be proud of yourself. Yes for solving the puzzle (which was epic btw) but more because you had the courage to do it live, knowing so many people, including your peers were watching. Respect.

[Terraloper]

That outro made me want to cry. This man is an international treasure.

[Pheehelm]

One particularly fun bit from the chat on this stream was when we started sharing facts about Phistomefel. A few of them I remember:

Phistomefel set a 5 on a German whispers line and the solver accepted it.
Phistomefel set a 1 and a 9 on a between line.
Phistomefel once set a ten-cell thermo.
Phistomefel once set a palindrome line in a single column.
Phistomefel set a miracle sudoku that was confirmed by the Vatican.

[Playmaker]

Without doubt this is one of the GREATEST Sudoku solves ever, and to think that I could even keep up with every deduction from Simon is even more incredible. Elegant puzzle with elegant solve path!! ;)

[Hker]

You know -- there has been so much emphasis on how next-level hard this puzzle is, what with Phistomefel's warning and Simon's "fear", but if we subtract out his chat and the distraction associated with that interaction, he did that puzzle in mere "movie" length. I'm beginning to think Simon could do any logical puzzle in a reasonable video. So impressive!

[JPgreekgaming]

That's it, I'm cancelling Netflix...This right here, this solve alone was far more entertaining and an incredible emotional roller coaster, more so than any big movie I'v seen all year! I genuinely teared up along the way seeing Simon so stressed and worried (feeling sorry that he is wasting our time... how much more wholesome can you get) and finally breaking it open and that final sigh of relief!

[SnowTheJamMan]

Fantastic stream Simon, you kept aplogising for being slow but i was fully engaged for the whole two hours, and so was everyone in chat. That guitar outro was the perfect ending to the stream.

[inspiringsand]

Rules: 9:43
Let's Get Cracking: 10:52
Puzzle Solved: 2:07:36
Simon's time: 1h56m44s

What about this video's Top Tier Simarkisms?!
Bobbins: 6x (04:42, 04:44, 04:44, 04:46, 07:02, 2:01:26)
Knowledge Bomb: 2x (27:53, 1:51:39)
Goodliffing: 1x (1:55:47)
Three In the Corner: 1x (34:13)
Cooking with Gas: 1x (54:41)
You Rotten Thing: 1x (1:17:32)

And how about this video's Simarkisms?!
Hang On: 20x (17:03, 21:22, 29:27, 29:41, 36:58, 37:01, 40:37, 40:37, 41:21, 41:23, 41:25, 1:00:27, 1:27:22, 1:31:24, 1:34:22, 1:35:12, 1:35:13, 1:38:22, 1:38:22, 1:40:29)
Beautiful: 16x (29:35, 29:38, 35:39, 35:40, 1:12:27, 1:26:58, 1:38:55, 1:38:55, 1:39:01, 1:43:18, 1:56:43, 2:05:06, 2:10:13, 2:10:26, 2:11:10, 2:12:11)
Sorry: 14x (03:35, 08:07, 09:18, 30:12, 34:40, 38:54, 51:47, 1:18:48, 1:26:20, 1:26:31, 1:57:47, 2:07:48, 2:09:16, 2:15:02)
Phistomefel: 11x (03:48, 05:44, 06:01, 30:49, 47:47, 1:12:33, 1:49:30, 2:01:52, 2:02:10, 2:02:24, 2:12:41)
Goodness: 11x (34:36, 49:28, 1:01:43, 1:36:27, 1:43:03, 1:43:06, 1:48:39, 2:08:00, 2:08:32, 2:08:34, 2:09:35)
Nonsense: 11x (14:05, 14:07, 22:53, 42:34, 50:57, 54:16, 1:02:57, 1:06:46, 1:08:12, 1:08:25, 1:24:39)
Obviously: 7x (06:12, 36:41, 38:35, 1:36:47, 1:44:47, 1:50:27, 2:00:09)
In Fact: 5x (34:04, 1:04:22, 1:50:49, 1:56:37, 1:58:12)
Surely: 4x (24:30, 24:33, 1:23:28, 1:26:04)
Ridiculous: 3x (22:53, 2:02:01, 2:02:12)
I've Got It!: 3x (1:40:38, 1:40:40, 1:40:53)
Good Grief: 2x (03:30, 05:33)
What a Puzzle: 2x (2:08:06, 2:09:00)
Clever: 2x (1:12:49, 1:12:53)
Stuck: 2x (04:28, 07:06)
Come on Simon: 2x (1:47:59, 1:50:09)
Magnificent: 2x (08:43, 2:02:37)
What on Earth: 1x (14:15)
Nine In the Corner: 1x (2:10:20)
Bother: 1x (2:00:52)
Naked Single: 1x (1:55:41)
Secret: 1x (2:08:52)
The Answer is: 1x (1:52:09)
Out of Nowhere: 1x (1:58:48)
I Have no Clue: 1x (52:31)
Brilliant: 1x (2:02:28)
Break the Puzzle: 1x (1:36:19)
Fascinating: 1x (2:11:52)
Incredible: 1x (1:55:37)
Extraordinary: 1x (05:53)
Gorgeous: 1x (2:11:15)
Oh It Can!: 1x (09:41)
Disconcerting: 1x (1:24:03)
Epiphany: 1x (07:08)
Witty: 1x (1:58:28)
Proof: 1x (2:02:06)
Going Bananas: 1x (00:37)

Most popular number and colour this video:
One (202 mentions)
Green (76 mentions)

Antithesis Battles:
Even (15) - Odd (2)
Lower (4) - Higher (2)

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!

[grimsqueaker]

What an emotional roller coaster from Simon. Nervousness, absolute concentration, relief, awe, embarrassment, and all with the greatest humility. Thank you for being brave and giving us this amazing solve.

[dionarlyn]

Absolutely brilliant. Simon's humility and appreciation for a mad genius level puzzle WHILE being a mad genius is so endearing. Just been watching this week, and such a fan of this channel and Simon.

[PvPSteve]

Phistomefel interview on how this puzzle was set would be really interesting!

[xOscarAx]

when he was nervous at the end playing the guitar i nearly cried. your such a wholesome person. amazing solve, im so glad i was able to follow the logic from the start, you have a nice way of explaining logic in an understandable way. thank you so much

[maljamin]

Once, Phistomefel set a sudoku with fewer than zero given digits.

[thoughtbyte]

LEGENDARY puzzle, LEGENDARY solve. One of the great achievements of the channel. Bravo!

[brianarsuaga]

What an incredible puzzle and an incredible solve. A couple years ago I could never have guessed that watching someone else solve puzzles that I can't would be so entertaining.

[anthonyserafini]

As the beast emerges from the shadows, a great fear strikes the men’s heart. The sound of their swords falling to the ground was second only to the sound of the earth shaking to such a dark presence. It many eyes lacerated the soul of those who tried to face it.
But, when all hope was lost, one Knight, covered in fear, manages to stand against the horrific creature. It was no other than Sir Simon, from the house of Cryptic, known amongst all kingdoms as one of the mightiest knights. He starts to march in the direction of the beast. As he gets closer, a devilish voice begins to taunt his heart. The one known as Phistomefel speaks in Simon’s head:


—Phistomefel: Ah, wasn’t expecting any one else. You might have challenged me in the past, brave knight, but now you are facing my greatest creation, one that even I fear. Do you really hope to achieve victory today?


— Sir Simon: Well, it is my duty to fight. You might think it’s possible for you to win, but the answers is no. For me, a dangerous creature is no more than a puzzle. It has a hidden weakness that needs to be discovered. Therefore, I should give myself a go. So — he says while raising his sword and shield — let’s get cracking.