Four Zeds/Zees - but Don't Go to Sleep!

Normal sudoku rules apply. Digits on an arrow sum to the number in the attached circle. If the Nth digit from one end of a coloured line is X, the Nth digit from the other end is 10-X.

▶ SUDOKU PAD - Our New App ◀ NOW AVAILABLE - 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 it is NOW AVAILABLE at these links:
On Amazon: Search for “SudokuPad”

▶ OUR PATREON PAGE – JOIN THE COMMUNITY, SUPPORT US AND TRY OUR PUZZLE HUNTS◀

▶Our merchandise is all here: ◀

▶ CTC FAN DISCORD SERVER◀

▶ OUR BACK CATALOGUE – ALL CATEGORISED WITH LINKS!◀

▶ WHY NOT TRY OUR CLASSIC SUDOKU APP? ◀

▶ OUR KILLER SUDOKU IS ALSO AVAILABLE◀

▶ YOU CAN ALSO TRY OUR SANDWICH SUDOKU APP ◀

▶ TRY OUR CHESS SUDOKU APP◀

▶ HERE’S WHERE YOU CAN TRY OUR MIRACLE SUDOKU APP◀

▶ THERMO SUDOKU is available too!◀

▶ YOU CAN ALSO TRY OUR ARROW SUDOKU APP ◀ Here are the links:

▶SEND US PUZZLES TO SOLVE/CONTACT US◀
Snailmail: Mark Goodliffe, Box 102, 56 Gloucester Road, London SW7 4UB

▶FOLLOW US◀
Twitter: #crypticcracking
@crypticcracking

▶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

[steve]

10:40 for me. I really like the puzzle.

Logical error around the 7:45 mark. It seems Mark misread the arrow and put a 9 in r2c5 when it should have gone in r1c7, and just got lucky in that they both happened to be 9s.

Turns out, that was fairly easy to prove logically from that point. The 5 on the arrow forces a 9 into r1c7 and a 13 pair in the other 2 cells on that arrow. The 9 forces a 1 on the other end of the yellow line, disambiguating the 13 pair, and the newly-placed 1 forces a 9 into the other circle via the yellow line.

[Trias]

I've had a really rough time lately and these puzzles help me keep my mind occupied with something else than my problems. Thank you so much for that.

[fluscim]

82 minutes. Now to learn how to do better than that. :-) Edit: with a mistake? Wow. Ok. Realised 5 early, as in probably 20 min :'-D. Mark's efficiency comes from (at least) a faster mind, a knowledge of sums by heart, and a panoramic view of what interacts with what. I can work on the second and try to emulate the third. Useful to reflect on how to improve. Thanks for the puzzle (Adrian) and the channel (Mark, Simon et al, patrons) and the app (Sven, patrons).

[andrewnelson]

I never grokked that r2c8 had to be 5, I was treating it as unconstrained and that really gave me a roadblock that slowed me down for quite a while.

[jwolfe]

I had 20:00 exactly, even with distractions. I noticed right away the 5 thing and was kind of surprised when Mark didn't. Our solution paths were actually quite different. There was some cool logic the way Mark did it and there was some different cool logic the way I did it.

[nickatty]

I really liked that unusual rule, and the way the arrows and the lines interacted was very nice indeed. I take things a bit slower (as otherwise I make too many horrible mistakes) but this time was only a couple of minutes slower than Mark which is quite something. I liked it in that I kept having to stop and think, but never got completely bogged down and not sure what to do.

[stevieinselby]

I really enjoyed that ruleset, and I can a lot of potential for some very interesting ways to use it – great work 👍🏻
Completed in just under 15 minutes – pleased to say I realised the 5 trick early on, and also that I didn't at any point add up the digits on an arrow _and then put the total in the circle for a different arrow_ 😜. I started with the arrow in box 4, which was surprisingly restricted from the start.

[Kaiser]

Loved this ruleset! It took me far longer than I'd like at 44:46, but enjoyed every minute.

[markp]

8:28 finish. Realized the center 5 on the odd lines right away, which helped start me off. From there, it was just seeing how the X-lines (™) 🤣 and arrows interacted with each other. An excellent little puzzle!

[Ardalambdion]

Thanks for an interesting use of a palindrome line. As I have noticed much of lately is that there is a strict path in the first 3rd of the puzzle, but here I could start almost anywhere.

[jacobcombs]

34:01 I zeroed in on those 5s pretty fast, while wrapping my head around the X and 10-X rule then moved to the 8 and 2, then started filling in circles and it all just flowed together so nicely. Love this puzzle. And I was only 50% slower than mark instead of the usually 100-200% slower!

[srwapo]

47:29, spent like twenty minutes staring at it before peaking at the solve and THEN realizing that a 5 had to be in the center of an odd length colored line!

[lukaszpiotrluczak]

You got better prenuntiation than many foreigners and some Polish people :) good job.

And you polished this puzzle very well - it wss nice to watch.

Thank you!

PS: Don't even try to spell my name - many Polish can't do it right ;)

[benjaminrealy]

29:56. Favourite ruleset ever...so far. 10/10

[oldguydoesstuff]

I joined you in a stumble near the end. Of course, I also joined you just to GET near the end. I did get started by dealing with box 4, pretty quickly figuring out there was only one possible arrangement of digits along the Z line. Then some faffing about with the arrows until I broke down and started watching your solve. I didn't figure out the thing with 5 on the yellow line until I watched you do that. That was the breakthrough I needed to get moving again.

[davidh.]

67:28. It was slow, but never really difficult, and never hung up for very long. And the way the pairs interacted around the grid was quite fun to figure out. That makes this a good one in my book.

[TiagoMorbusSa]

Holy crap, the way you manage to find out where the mistake is! So efficient and calm, I immediately rage quit when I make a mistake like that XD

[RaghavendraBommaraju]

At 7:47, is the circle in box 2 also pointing to the arrow in row 2? If not, why is the center cell in box 2 a 9? Couldn't it be a 7? Thanks!

[jaredbitz]

Fun bit of logic that I didn't see Mark use - the three squares on the arrow in box 4, plus r6c2 have to add up to 20. But since the two cells on the arrow itself sum to the digit in the circle, that means the three together must add to an even number. This means that r6c2 is even, which I used in my solve to eliminate the possibility of a 9 being in that cell.

[Jodawo]

I actually like that new rule better than I like the palindrome rule. I think this new rule could create some very interesting new puzzles. Once you learn the characteristics, such as, if there is a center to the line it will always be five. This was definitely a fun puzzle and congratulations to the center not only for getting a feature but also creating a new rule set that has so much potential.