This Sudoku Was Made By A Wizard

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▶ABOUT US◀
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 eleven-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

[ItsSansom]

Find yourself someone who talks about you like Simon talks about symmetry in Sudoku puzzles

[zanelamb]

When I saw that all the complement numbers totalled to 9, and the central 3x3 has all the pairs opposite each other surrounding the 9, my brain melted. What a beautiful, satisfying puzzle!

[sihplak]

The thing I noticed about the symmetry is that all symmetrical number pairs add up to 9. In other words, every time you solve a 1, you solve an 8. Every 2 solves a 7, every 3 solves a 6, and every 4 solves a 5.

[Kolateak_]

“Oh, it’s over” “Wait it’s been 20 minutes?”
I don’t know why this was in the recommend but I just sat and watched someone play sudoku for 20 minutes but I swear it was more like 8

[drunkenknight]

How is this the best let’s play I’ve seen

[NovaGuardian]

I don't even like sudoku. Not sure why this was recommended to me. But I watched it all and still gave a like just because of Simon's reaction and pure joyous wonder. Even if you don't like something yourself you can still see the beauty in something that someone else is truly passionate about.

[DevilishlyDutch]

That’s not a puzzle, that’s a piece of art

[shadyparadox]

It's not part of the rule set, but the solution wraps around the "consecutive" rule as well, in that no 1's and 9's are adjacent in the final solution either.

More than that, the adjacent rule also wraps around the edges of the board as well.

Even more than that, the knight's rule wraps around the edges too.

[migi]

As a physicist whose whole career centers around symmetries in nature, it was wonderful to see this symmetry blossom like a flower from such seemingly innocuous initial conditions.

[briancouchman]

When you figured out that 1 and 8 were paired I said that forces 9 in the center center... and it did.

[policarpo]

And Gurth’s symmetrical displacement is hiding in this puzzle, even with so few digits!

[tone]

Absolutely lovely puzzle. I noticed the potential for Gurth's symmetrical placement pretty early on, but assumed it wouldn't actually come up because the additional rules gave a way to break the symmetry later on, but it was cool to realize that even with all the extra restrictions it still worked. (Although I don't know if it _has_ to work, since a solution could put 1s next to 9s in order to make itself unique without breaking the initial symmetry.)

[OrestisRT]

Took me 2 hours, but solved it. This was one of the most satisfying sudokus I've ever seen.

[wheelc]

Here is what I guess:
Each pair of symmetric numbers sums up to 9 (so 9 has to be on its own and therefore has to sit right in the middle).
So if we rotate the entire sudoku 180 degrees and sum up all the corresponding digits we get all 9's except 18 in the middle.
Also since 9 has its special role there's no need to give any 9's at the beginning.
And for the 4 pairs 1-8 2-7 3-6 4-5, to minimize the initial clues the designer avoids giving the 1-8 pair due to the consecutive number rule.
And for the initial positions, putting the numbers closer to the middle maximizes the power of the knight rule, hence minimizing the number of initial clues.
Given the rigidity of the additional rules, I wonder if this is the only possible configuration under the new rules and only 8 initial clues (treating its reflections and rotations as the same).

[aaronstrager]

As a mathematician, this puzzle got me so excited the instant the “trick” was discovered (I’m still not sure how it ended up in my recommended videos though)!

[Lee]

Not sure how YT got me here, but it did and I love it. I never did any Sudoku with rules beyond the standard ones.
This was a work of beauty. I neer thought I'd enjoy watching Sudoku solving THIS much. Great vid, instant sub.
Rishi, please create more of this!

[BryanLeeWilliams]

I'm tickled at how tickled Simon gets by the symmetry of this puzzle.

[xXBlazingDragonXx]

I stumbled upon this quite randomly due to YouTube's wild algorithm, but I'm not mad at all. I used to be fascinated with Sudoku puzzles when I was younger, and watching you get excited over such an expertly built puzzle has inspired me to get into Sudoku a little more. It's a seemingly simple puzzle game that has more layers to it than many could ever guess. I love it.

[KingApeiron]

I'd never done a sudoku with rules beyond the standard set... this one took me an hour XD

[oitzmark]

actually a not bad watch, unsure how i got here tho #youtube algorithm