This Sudoku Looks Like That Numberphile Video!?

** TODAY'S PUZZLE ***
This is a simply phenomenal sudoku tonight from relatively new author blackjackfitz. It's called Overlap and it's certainly fair to say that the initial grid should put one in mind of a recent Numberphile video (in which Simon explained the Phistomefel ring... link below!) Is theory necessary to solve this puzzle though?

Have a go at the puzzle here to find out:

Rules:
Normal sudoku rules apply. Along a marked diagonal, digits cannot repeat. Cells along a purple line contain a non-repeating, consecutive set of digits. (These digits can appear in any order).

Simon's Numberphile video is here:

*** NEW SANDRA & NALA FOG PACK ***
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Other treats on Patreon include:
- the new James Bond sudoku hunt competition;
- Simon's latest forays into the world of Islands Of Insight;
- Mark's video looking at the new OneUp puzzle from Rodolfo Kurchan;
- his solve of Region Geometry by Emre Kolotoğlu (3hr 36min long...!);
- and Mark's latest solve of The Times Club Monthly cryptic crossword

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▶ Contents Of This Video ◀

0:00 Theme music & puzzle intro
1:02 Our Sudoku Club
1:24 Rules
3:37 Start of Solve: Let's Get Cracking

▶ Contact Us ◀

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[blackjackfitz]

Thank you so much for featuring this, what a lovely surprise!

This was originally set for the monthly puzzle prompt on discord where we were asked to use just a single constraint. Now you might be thinking “but you used renbans and diagonals!?!” But what is a diagonal if not a length 9 renban?

I kept the diagonals with the standard notation because it was less cluttered in the corners of the puzzle, and because it better telegraphed the break-in.

I will say that this puzzle was also inspired by Riffclowns sudoku hunt, I wanted to try something with overlapping lines and this is what came out.

Much love to everyone in this community, I hope you enjoyed solving this puzzle as much as I enjoyed making it!

[Babinzo]

The proof of Phistomefel finishes at 07:05 for those already familiar with it.

[iain_nakada]

There was a nice bit of logic that Simon bypassed. After identifying all the corner sequences, we now know the composition of digits in blue (and hence green). There's a 1, a 9, and 2 of everything else. We can then look at the 5-digit runs in green.

There must be a 12345, and a 56789. All runs contain 5 (obvs) and the 5s are duplicated.
We have 2 more slots that duplicate a value. What goes in them?
The second 2 required must be in a sequence 23456.
The second 8 required must be in a sequence 45678.
Therefore the remaining duplicated numbers are 4 and 6 (and can be immediately placed), and we know what the 4 runs are.

Excellent puzzle, blackjackfitz!

[taliesintown]

Digits?! In my puzzle! How dare blackjackfitz! It’s almost as if Simon will have to use a little known technique called Sudoku…
Looking forward to watching the video as always Simon!

[TurquoizeGoldscraper]

39:20 for me - very clever use of overlapping renbans and the Phistomefel ring.

[HunterJE]

13:41 I think for the diagonals version the yellow/orange shaded part is not necessary to the proof - all the cells on the diagonal not in box 5 are *already* on either the phistomefel ring or the corner 2x2s; a digit not in the phistomefel set at all won't appear in either copy, which forces both diagonals' instance of that digit in to box 5 and thus on to their intersection

[al]

Hmm, one from Simon's pre-record catalogue? unless I have my days wrong, but it certainly isn't Sunday which he introduced the video as.

[emilywilliams]

I downloaded this puzzle, sure that I could solve it all on my own. I looked at the Phistomefel ring and the corner 2x2s and did a lot of the thinking that you did, Simon - but I ran into things that were a bit beyond my ability to figure out, I felt - so I settled down to enjoy the video. Thanks - brilliant, of course. I was especially impressed that you figured out the usefulness of the overlaps, which I had an inkling about but could not fully flesh out.

[zaps-aim]

For what it's worth, the j in mahjong is generally pronounced like the j in jet, not the y in yet. Incidentally, one of the previous sudokus you solved - one where the final clue was in morse code embedded in the grid - was co-designed by a member of the UK japanese mahjong community, IIRC.

(and just by the by, mahjong in this context refers to the multi-player game, not the solitaire game: the difference between them is as large as the difference between playing-card solitaire, and poker).

Best wishes, and thanks for all the sudokus, from All-Ireland Mahjong.

[thejuggler]

That's an insane break-in, well done Blackjackfitz!

[nonyobisniss]

I gave up at this one. Then while watching an unrelated video I had a brainwave, returned, and completed it. Nice when that happens.

[inspiringsand]

Rules: 02:18
Let's Get Cracking: 03:52
Simon's time: 39m40s
Puzzle Solved: 43:32

What about this video's Top Tier Simarkisms?!
Phistomefel: 10x (00:28, 00:46, 03:59, 04:02, 11:28, 13:39, 18:26, 31:26, 36:31, 39:02)
Three In the Corner: 3x (32:12, 32:15, 32:27)
Bobbins: 2x (28:21, 28:21)
Maverick: 2x (08:51, 34:14)

And how about this video's Simarkisms?!
Sorry: 6x (10:35, 21:45, 21:57, 32:46, 33:23, 37:11)
Ah: 6x (07:39, 28:28, 30:10, 34:03, 35:35, 43:18)
Clever: 5x (25:14, 25:14, 26:46, 30:28, 31:36)
In Fact: 5x (00:55, 03:16, 07:31, 21:48, 32:10)
Hang On: 4x (07:39, 16:10, 32:35, 35:07)
Whoopsie: 4x (23:24, 23:24, 23:24, 29:40)
Beautiful: 3x (37:54, 42:56, 43:49)
By Sudoku: 3x (29:42, 37:42, 41:15)
Pencil Mark/mark: 3x (10:43, 38:18, 38:30)
Ridiculous: 2x (31:41, 33:08)
Proof: 2x (04:19, 04:26)
Obviously: 2x (06:47, 34:56)
Wow: 2x (11:06, 11:06)
What Does This Mean?: 2x (17:37, 44:07)
Nature: 2x (44:22, 44:24)
Symmetry: 2x (24:57, 40:29)
Good Grief: 1x (41:18)
Goodness: 1x (43:24)
What a Puzzle: 1x (43:30)
Bother: 1x (40:52)
Naked Single: 1x (37:13)
Nonsense: 1x (07:42)
In the Spotlight: 1x (32:31)
Brilliant: 1x (44:25)
Fascinating: 1x (17:29)
Going Mad: 1x (36:46)
Deadly Pattern: 1x (42:34)
Gorgeous: 1x (26:46)
Take a Bow: 1x (43:36)
Magnificent: 1x (41:45)
Progress: 1x (22:11)
Weird: 1x (07:01)

Most popular number(>9), digit and colour this video:
Fourteen, Sixteen (4 mentions)
One (96 mentions)
Green (35 mentions)

Antithesis Battles:
Even (3) - Odd (0)
Black (5) - White (0)
Row (8) - Column (5)

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!

[stevieinselby]

After marching confidently into several dead-ends – when I thought I had seen how the renbans had to be constituted but then realised I had got it completely wrong – I eventually proved to my satisfaction that the outer corners were some combination of 1, 2, 3, 4 / 2, 3, 4, 5 / 5, 6, 7, 8 / 6, 7, 8, 9, with the overlap cells on the inner ring being 4, 5, 5, 6 ... but I couldn't see how to move on from there 😵‍💫
(It may have been for artistic effect, but am I right in thinking that the small squares in the corner boxes are superfluous to the solve?)

[frankjiang]

Finished in 11:48. But I admit I took a nap between reading the rules and solving for real as I needed more sleep before solving anything. I had been noodling for a little bit before taking the nap, and before I went to sleep realized that the middle parts of the 4 corners had to contain a 3 or 7 guaranteed which guaranteed that they had to contain a 234 triple or a 678 triple which made the break-in pretty trivial with the numbers in place and made solving this really straightforward.

Fun puzzle!

[NoobixCube]

The first couple of times you said "Ma-yong" I was thinking "nice use of the soft J", because I was fundamentally damaged by Anchorman, but the urge to correct is rising. The J is as the G in Geoff, or giraffe, or the J in judge, jam, and jelly. Across Asia there's a variety of different phonetic pronunciations, including different words entirely, but in none of them is the J a Y! ;-)

[june]

32:16 "I didn't do anything for a 3 in the corner!" - Simon, after cracking logical problem after logical problem for more than 28 minutes straight without being rewarded with a digit until a minute ago...

[louisesuth]

that was just such smooth setting! lovely!

[chocolateboy]

I got 95 minutes. I tries to do it all in my head, but I had to write down my thoughts on paper. That really helped and made seeing the interaction between the corner clues, the blue clue, and the existing numbers much more noticeable. I really like this one. Great Puzzle!

[DarrenNakamura]

Finished in 80:11. This is a perfect example of a puzzle I wouldn't have had a chance of even starting before I started watching Cracking the Cryptic. Some wild deductions in the start. I'm wondering if there was a simpler way for me to do it, even.

[ericpraline]

Clever construction. Am having a torrid time at the moment with CTC puzzles, perhaps I'm running out of steam, but it only took a few seconds of watching Simon's solve, without any direct hints, to somehow focus my mind and take a decisive step.