The World's Most Famous Puzzle Maker

*** STOP PRESS: BUY OUR BOOK WITH A SPECIAL DISCOUNT ***
To celebrate achieving 500k subscribers, we're trying to say thank you in a couple of ways. We're able to offer our Cracking The Cryptic Greatest Hits book at a discount for a limited period.

The coupon code is “500SUBS” and it can be redeemed at checkout here:

We'll also be releasing a free app full of handmade puzzles to celebrate reaching 500,000 subscribers on YouTube. Hopefully on MONDAY!

*** Today's Sudoku ***

Aad van de Wetering's sudokus have been watched about 10 million times on Cracking The Cryptic. And his latest puzzle, Swirling Fifteen, is a great example of why. We defy anyone to solve this and not enjoy it - it's just a gorgeous experience.

Give it a try at the link below:

Rules:
Normal sudoku rules apply. In every cage, the digits must sum to 15. The central 3x3 box (in grey) is "semi-magic" ie its rows/columns sum to 15 but its diagonals do not necessarily sum to 15.

*** Join Our Sudoku Club On Patreon ***

August's monthly reward is out and so far we've had over 2000 correct entries! It is a Genuinely Approachable set of Sudokus with Puzzle elements - we're calling it GASP! The feedback so far has been great with lots of people managing to finish the monthly reward for the first time.

Join us on Patreon for as little as $2/month to try it out here:

*** Our New App Is OUT ***

Our new app is OUT on App Store AND Android AND ON PC (via Steam)!!

We've completely revamped the interface. Now you download the basic app free and you can choose to download additional content. So 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 (so there's a killer sudoku, a miracle sudoku, a thermo sudoku, etc). 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: Phistomefel, clover, jovi_al, Christoph Seeliger, Qodec, Sam Cappleman-Lynes and Richard Stolk have all contributed sudokus!!

▶ Contact Us ◀

Twitter: @Cracking The Cryptic

Our PO Box address:

Simon Anthony & Mark Goodliffe
Box 102
56 Gloucester Road
London
SW7 4UB

(Please note to use our real names rather than 'Cracking The Cryptic'.)

▶ SUDOKU PAD - Our New App ◀

It's OUT on Windows via Steam here:

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. Already available on IOS and Android.

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▶ SIMON REACTION BOARD (!) ◀
With thanks to Andrea for creating this :)

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▶TRY OUR CLASSIC SUDOKU APP◀

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Melvyn Mainini

[oliviamartinez]

I’ve heard Simon explain "the secret" to me a thousand times and I still smile every time he explains it and says I’m one of his favorite people

[sarppagamer]

Thank you so much for being here every day.
My grandmother sadly passed away this morning and she's the person who taught me how to solve sudokus. Watching your videos has now been a daily habit of mine for a good while and watching this today reminded me of the times when I used to sit next to her as a child watching her solve multiple sudokus in row. They were almost the only times when she could just sit down and calm down teaching me to enjoy sudoku and it's calming effects as well.
I can't really put it into words too well, but I'm so thankful for you being here sharing this content, it is helping me stay grounded(?). Thank you so much.

[reganmartin]

About 15 minutes into the solve, I actually said out loud, "Oh, this is beautiful!" And then laughed so hard! I love this channel! It brings me so much joy!

[johnnywlife]

Solved by the world’s most famous puzzle solver

[stumbling]

I love that every time Simon tells "The Secret" he goes into 70's Childrens' TV Presenter mode.

[sjm]

"Aad is normally fairly generous with given digits... in the sense that he doesn't normally give me zero"

[debrawilden]

(About min 19-In filling in the green 6-9, Simon removed ALL greens in order to preserve only the solid greens so when he highlighted the greens, only the solids would be filled. I live Simon--He later realized that he wanted the flashed green cells back! It would been easier to MANUALLY highlight the solid greens to start with.)

[davidhughes]

I love the longer videos because of the drama, intrigue, insanely difficult logic, but loved this puzzle solve because it highlighted the pure beauty of logic. Thank you Aad, and of course, thank you Simon.

[Primefac]

I don't usually watch the videos I've solved solo, but I wanted to see if Simon used Phistomefel's Ring - which he did not! I started with the central box, got the 9 in Box 6 (which let me disambiguate the 78/69 pairs), then started filling out all of the 15s in the central boxes. I soon realised that the inner boxes were roped! After penciling those in, I could then pencil in the corner boxes (including recognising the Ring to place the 78s) and by that time it was just a case of using the given digits to fill everything out. Surprised to see so many different ways of solving this!

[Azeria]

01 hour 26 for me, it's a very good puzzle, and not too difficult for me to figure out eventually (especially with Sven's cage calculator!)

[ellisromero]

I think my first digit was the 9 in box 7!

I placed a 3 in the square in box 7, and then used the secret on row 4 to conclude that every row in box 7 added to 15.

Once done I determined that no combination of 6/9 with the 3 could make a valid 15 and thus the domino had to be a 78... the rest of the early logic from Simon held true for me with the difference bring I was pencil marking 69s and 78s!

A truly splendid puzzle.

[jaeusa]

@14:30 It makes me proud as a viewer that, as I sit here eating and watching, I thought to myself "Wait, there's a Phistomefel Ring here" and identified that each central square in boxes 1 3 7 and 9 had to be purple because 2 purples could not both inhabit a 3-cell 15 cage.
As irony would have it, Simon deduced the same in a a simpler fashion.

[SgTt]

Just discovered your channel today and what an entertaining video to start with. I’m not good at sudokus but watching Simon explain every single step of solving is absolutly fascinating. I didn’t think it was possible to solve sudokus that are so unfilled! Love the pedagogy and energy that you put info this. I can’t wait to watch another one.

[markp]

22:34 finish. I worked the opposite way that Simon did to differentiate the 15 pairs. Since the 6-9 had to be diagonal to each other in the 2x2 section in the magic-ish square, one of them would always be in row/column 5, meaning that the 15 pairs adjacent to the center had to be 7-8. THEN I established where they would go in the center box. I was slowed down a bit by trying to force regular sudoku and ignoring the cage sums, hoping that it would play itself out more. It didn't. Another amazing puzzle!

[ConflictZv]

I'm still new to these variant puzzles but I find them very satisfying to try and work out. Whether I succeed or fail it's interesting to see how my logic path aligns or diverges from Simon's. Sometimes I will find things immediately that he struggles to see and more often he spots things that would take me forever to deduce. Always more to learn, love the videos congrats on 500k and 5 years of brilliance intertwined with elegance <3

[klausku]

I really love Aad‘s puzzles. This is no exception. Took me a while longer because I missed the trick in the semi-magic box. My first digit was the 5 in box 9 and it went smoothly from there. A real masterpiece with beautiful and approachable logic. Thanks!

[carl]

The whole puzzle was "magical", not just the central box.

[jensstalberg]

Nice one, I had a totally different solve path (yes, double the time of Simon's...) by using the secret on the outer rows and columns. Since there was 30 in five cells, the other four had to add up to 15, and you need a 7 or an 8 to do that due to how the 15 dominos was placed. That put the high digit (7 or 8) in the corner due to similar colouring as Simon did, giving just a few alternatives to go. By then using the givens it was pretty straight forward to fill in the grid, and to disambiguate the later parts some use of the semi-magic square fixed that.

Really happy to have been able to solve this, Aad puzzles are not really in my leauge normally. Thanks for the brilliant channel, that really gives me so much joy.

[MarushiaDark]

Aad once again proving why he's the world's greatest setter.

[CineMiamParis]

My time is pathetic. My board looks like an Hawaiian shirt with a hangover. My vocabulary is PG-13. Yet, this is my 3rd non-Gas solve with no help. Simon, Mark, and the community, thank you so much for keeping my brain challenged. And congrats on the 500K.