This Puzzle is not Nonsense

On our new app, there's a FREE pack of puzzles by Prasanna Seshadri and a paid pack: DOMINO SUDOKU! Prasanna's free pack includes one puzzle for each variant of our existing apps. Domino Sudoku is a pack of 100 handmade puzzles (40 on launch, 5 added each month for a year) by some of the best constructors in the world.

▶Music◀Tim McCaskey (Guitar) or Lucy Audrin (Piano) or Riffclown plays Mozart's Sonata no 16 ("Sonata Facile")

▶SOFTWARE◀Play the puzzle in the video by clicking the link under the video (above). Thanks to Sam Cappleman-Lynes and Sven Neumann for their work.

▶Logo Design◀Melvyn Mainini

▶Opening Credits Design◀Joel Blundell

▶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 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

[darreljones]

This puzzle is easier if you remember the rules about symmetrical sudokus (which Simon explained in an older video): If a sudoku has complete symmetry, and a unique solution, that solution must be completely symmetric as well. In this case, the symmetry is rotational: All 1's map to 3's, 2 similarly maps to 4, 5 to 6, and 7 to 8. Any such puzzle always requires one digit map to itself, and in this case it's 9. Not surprisingly, there's also a given 9 in the central square.

[emilywilliams]

This was great, Mark, a very interesting puzzle and solve. As I always do, I learned more things to think about when solving this type of irregular/windoku kind of puzzle. As I watched you, I felt that the key to this one was paying close attention to the different regions of the puzzle. Rows and columns are easy to scan; the irregular regions are not as easy; the windoku areas are kind of familiar but it is easy to miss something. Very good demonstration of NOT being a stormtrooper and scanning very well on your part, I thought! Thank you (and Simon) for all that you do to bring two puzzles a day to this channel. That is not all I'm thankful for, but it is what comes to mind right now! (And meanwhile, as I'm writing this, it appears that CTC has 499k subscribers ... almost ready to tip over that amazing and well-deserved number!)

[davidh.]

Well, it was 2½ hours for me, almost exactly. Quite tough, and one of those hunt-and-peck types that can be so frustrating to work on. Even though I know some of the tricks of irregular and windoku, I found it extremely hard to find places where they actually applied. At least the symmetricity helped.

[wanderlustwarrior]

39:41 for me. I thought I was quick, but I wasn't even close to this video's length. Still, once it clicked, it really started moving along!

[bluerizlagirl]

This was a lovely puzzle -- and a great exercise in remembering to rub out redundant pencil marks when placing a full digit!

[rayflyers]

The video length is not 3 hours, but I can't be sure that the footage isn't playing at septuple speed.

[inspiringsand]

Rules: 01:17
Let's Get Cracking: 01:54

What about this video's Top Tier Simarkisms?!
Maverick: 1x (09:31)

And how about this video's Simarkisms?!
Sorry: 6x (03:32, 05:44, 09:40, 15:20, 15:32, 16:14)
Symmetry: 6x (02:39, 05:16, 05:19, 15:59, 16:29, 19:52)
Ah: 5x (06:07, 07:20, 10:51, 13:15, 13:47)
Goodness: 3x (04:39, 08:33, 09:28)
In Fact: 3x (10:40, 17:40, 17:56)
Obviously: 3x (04:50, 14:09, 20:56)
Clever: 2x (22:47, 23:11)
Lovely: 2x (08:21, 22:43)
Brilliant: 2x (00:28, 21:03)
Pencil Mark/mark: 2x (02:36, 09:12)
Bother: 1x (17:28)
Nonsense: 1x (23:13)
Hang On: 1x (19:31)
Progress: 1x (10:16)
That's Huge: 1x (15:56)

Most popular digit and colour this video:
One (61 mentions)
Red (16 mentions)

Antithesis Battles:
White (3) - Black (0)
Column (16) - Row (11)

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!

[faddy]

Superb solve. Tamed a really difficult puzzle.

Spotted sets and geometry seemingly with ease. Sometimes it feels like Mark uses his brain to take a sledgehammer to puzzles but this solve was a chiselled masterpiece.

[longwaytotipperary]

This puzzle made my head hurt. Mark was fabulous!

[garlicgalore]

Crazy fun! A super learn-as-you-slog-through lesson in symmetrical puzzles. Thanks to Bill, and thank you Mark for letting me catch the solution to the x-wing nines before you did! 😁 Made me feel like a pro!

[logiciananimal]

Knowing from the start that there will be still other 1-9 regions helps.

[pixllo]

Ouch, took close to 2 hours to solve this... couldn't scan for my life.

Going to sleep now, work tomorrow will be a drag. Anyway, thanks for the puzzle haha

[dertigerbauch]

17:29
It's funny how Mark just ignores the fact that 9s inr7c9 and in r3c1 are ruled out by the bottom right and upper left regions...

[chipsounder]

Fantastic puzzle, so many different sets and symmetrical logic, great solve to👏👏👏👏

[danielcamp]

A quirky puzzle that I had quite a challenge getting my head around but I got a great deal of satisfaction from solving it.

[Ferrindel]

Hardest "easy" puzzle I've ever tried on this channel.

[hockeyhacker]

23:14 ... To be fair trying to see the regions is kind of hard to do and so could make for easy mistakes. If the program allowed different colored thick lines it would be a lot easier to see the regions. I think it would be fairly difficult if you have a hard time differentiating between the regions because multiple thick black lines near each other is not easy to see which cells are in which region, the fact it is symetrical helps a bit, but having a few different thick line colors would help a lot. Like if the 4 outter regions had say blue lines around 2 of them caddy corner and red lines around the other two in the opposite corners and then the middle "z" shape had say a purple line then the four regions not on the outside but not the "z" shape would be a lot easier to see. But all black, for example where the "z" shape is I kept seeing the 5 and 6 by the 9 as in it because of not seeing the lines between the 5, 9, 6. A highlighted edge is a lot easier to see on a mostly black puzzle then a black line is, it kind of blends in making it harder.

I personally would have opened the puzzle, screen shooted it black putting it in mspaint and then drew different colors around the regions and put that multi colored guide up on the second monitor to reference to see the regions because as you fill in more numbers it is harder and harder to see the regions because the thick black lines are harder to see when there are numbers in the puzzle.

Maybe that should be a future update to the app is the ability to change the color of the thick lines when making the puzzle so that the regions can be easier to see when the puzzle is in progress.

[raineca]

Jigsaw and Windoku are my worst variant. So I will happily watch this episode!

[Coyotek]

In general, I struggle on both Jigsaw and Windoku sudokus ... so I guess I shouldn't be shocked that it took me nearly an hour (59:05) to get through this one.

Tough puzzle (for me)!

[phihau]

I had a very hard time following this one. Might be all the different shapes and boxes, and the logic. But still a great video! Im moving on from a novise