Yet Another New Sudoku Variant!

Normal sudoku rules apply. The sum of the digits on a line between two circles is equal to the product of both digits in the circles. In each calculation, digits may be repeated.

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▶Credits◀
Music: Tim McCaskey (Guitar) or Lucy Audrin (Piano) or Riffclown plays Mozart's Sonata no 16 ("Sonata Facile")
SOFTWARE: Thanks to Sam Cappleman-Lynes and Sven Neumann for their work.
Logo: Melvyn Mainini

Opening Credits: Joel Blundell

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Hi! We're Simon Anthony and Mark Goodliffe, two of the UK's most enthusiastic puzzle solvers. We have both represented the UK at the World Sudoku Championships and the World Puzzle Championships. We're also "cryptic crossword" aficionados. Mark is the twelve-time winner of The Times championship and Simon is the former record holder for most consecutive correct solutions to The Listener crossword. We hope we can help your puzzle solving while also introducing you to some of the world's best puzzles.

Thank you for watching!
Simon and Mark

[richardstolk]

Brilliant Mark! You followed exactly the intended path! I’m impressed again by your speed of calculating the possibilities by heart! Truly amazing. 😀

[Banz_FPSB]

118:45... Probably shouldn't have started it at midnight after having slept 3 hours the previous night, it made the calculations way harder than it should have :p

[ericpraline]

Lovely stuff. How Richard maintains quality as well as quantity is mind-boggling.

[BlossomBlue]

The 68 pair in column 1 makes it impossible to have a 3 in both ends of the short line crossing from box 4 to box 7. Therefore you can only place a 1 in r8c3.

[Coyotek]

40:53 ... I made a couple mistakes along the way, but did find a proper pathway to the end.

I loved solving this puzzle!

[jkid]

Had a lot of fun with this one but gave up after I reached a second contradiction and didn't want to go back again again... All the same I got most of it but it took some hour and a quarter. Big props to Mark ofc for the humbling.

[inspiringsand]

Rules: 02:38
Let's Get Cracking: 03:39
Mark's time: 21m49s
Puzzle Solved: 25:28

What about this video's Top Tier Simarkisms?!
The Secret: 1x (07:36)

And how about this video's Simarkisms?!
Ah: 5x (05:28, 07:25, 11:19, 18:27, 19:12)
Sorry: 4x (12:48, 15:23, 23:22, 25:13)
Brilliant: 4x (00:21, 00:50, 02:03, 25:30)
Hang On: 3x (16:38, 20:00, 23:18)
Lovely: 2x (25:07, 25:28)
By Sudoku: 2x (15:51, 19:29)
Approachable: 2x (01:14, 25:58)
In Fact: 2x (05:25, 05:28)
Bother: 1x (22:44)
Astonishing: 1x (02:18)
Deadly Pattern: 1x (24:55)
Masterpiece: 1x (03:36)
Obviously: 1x (04:31)
Progress: 1x (15:27)

Most popular number(>9) and digit this video:
Twenty Four (11 mentions)
One (79 mentions)

Antithesis Battles:
High (6) - Low (4)
Even (2) - Odd (0)
Higher (2) - Lower (0)
Column (8) - Row (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!

[emilywilliams]

Very interesting new variant. I feel as if it is kind of like arrows with double-digit sums, but easier and more straightforward. Enjoyed your video solve of it, as always, Mark. Thank you.

[pi]

ouf the calculation speed. Just remember, this is a professional.

[David_K_Booth]

What a clever variant! Although it's a completely unfamiliar rule, the puzzle is not formidably difficult, which speaks well of the skill of the setter.

[psiphiorg]

For the long line in box 1, the way I figured it out was by considering the end digits to be A and B. In algebra, A+B+AB = (A+1)(B+1)-1. By itself, that isn't too interesting, but subtracting r3c1 from 45 gives us (A+1)(B+1)-1 = {41, 42, 43}. Moving the 1 to the other side gives (A+1)(B+1) = {42, 43, 44}. Neither 43 nor 44 can be factored into two numbers between 2 and 10 (since A and B have to be between 1 and 9), that means (A+1)(B+1) = 42, so A+1 and B+1 are 6 and 7 in some order, and therefore A and B are 5 and 6 in some order.

There was another way to rule out 3-9-3 on the diagonal line in r678c123: Since the 68's in column 1 see each other, one of the 234 pairs in c1 and c2 is a 23 pair and the other is a 24 pair. Either of those would rule out a 3 in one of the endpoints.

[wanderlustwarrior]

40:48 for me. I'm a bit surprised the breakthrough at the start (to get the 6/8s) wasn't more useful throughout the puzzle for my solve. I solved the 6/8s by finding that r8c3 and r4c2 both had to be 1.

[piarittersporn]

A really interesting puzzle. I enjoyed it very much ( with an extra piece of paper! 🙂)

[Spicarium]

I think a sudoku like this could be also fun if it used not the digits 1-9 but the digits -4 up to 4. Could have some weird restrictions and implications

[jeffreyrosas]

5:45 “they could both be 3’s.” No. That would force the 234 pairs to both be 2, 4, which would result in 2 8s in column 1.

[sanabas]

Would like to see more of that variant. Was really elegant, flowed nicely, and quite approachable too.

My path was a bit different, box 9 isn't too scary once you have the bottom row done. 3 x anything needs 20+ in the final 2 cells, 4x5 needs 16, 5x6 needs the other 2 cells to sum to 4, all impossible thanks to the triple you already have.

[ninjan]

Your link for the Steam version of the 23-Puzzle links to Classic Team Fortress. Dont think that's intended! Great video, as always! Thanks for all the great content!

[Sam_weiqi]

Took me 38 minutes. I was really surprised that my solve path was so similar to Mark.

[bristolrovers]

Nice solve, very quick but accomplished

Obviously the puzzle is quality, look at the creator, it's pretty much a given

[TiagoMorbusSa]

The puzzle link is broken, I believe.