A Sudoku With Just One Given Number?!

[@Shadow81989]

A Sudoku where we actually get a given digit!? Almost feels like a novelty at this point! xD

[@artursruseckis4242]

This was crazy. I quickly found the 7 in the middle row, then discovered that the puzzle is broken in box 1 and went to sleep. Some 10-15 minutes later, in the bed, my brain continued to play with numbers and 1+1 popped out. Had to climb out of bed and returned to computer :D

[@monnamonsta]

Nice story :D

[@jefferyzavala5456]

Sudoku addicting uh

[@bobkerolls13]

This video shows one of the quirks in Simon's explanatory style that I find so charming. He'll skim over some immensely difficult logic (for me) to quickly work out why a number has to be odd (or even why it's a strategy at all) but if it's a thermo sodoku he'll spend five minutes explaining why a 9 can't go in the middle of a thermometer...four times in the same video. And while that might seem like I'm being nasty, I really do come back specifically for this - that you get to really feel the consistency in personality and honest emotion every single day. Don't change a thing, I'm sure someone still hasn't worked out the 9 thing yet but got the even/odd thing right away :)

[@srwapo]

I love it when they work out some crazy logic to prove a number, but don't see a simple sudoku constraint that could have been used instead.

[@dhawkins1234]

@@srwapo Part of the reason why they're such good solvers is that they have so many patterns that they can try at any given moment. They never seem to run out of steam. So where you or I might spot an easier constraint than they do at any given step in the solve, we're far more likely to get stuck for longer once we can't spot anything. The best solvers can't always find the optimal solution path like a computer, but they can nearly always spot *a* path.

[@teliots]

He once spent over 7 minutes explaining an x-wing in a single video... after having already explained it hundreds of times before. The simpler the logic is, the more time he spends on it.

[@srwapo]

@@dhawkins1234 I mean, I learn something from the tangents, but it's definitely them putting on blinders when they see something. I find the most optimal solution cause I take an hour to do it right, lol! (or just start trying different numbers, which feels like failure)

[@robertmeadows1657]

And we’ve locked a three into rows two and three in box one, and we’ve locked a three into rows two and three in box three, so ask ourselves, where can a three go in box two? Well, it can’t go here and it can’t go here so it must go in row one in box two--for the fifty third time.

[@Afterthoughtbtw]

Surely by this point, the title should read: "A Sudoku with a WHOLE given number!"

[@toneloc7910]

You have a good point. And don't call me Shirley.

[@theatog]

I am waiting for "A Sudoku with HALF a given number!"

[@steve470]

@@theatog It's only the right half, so it could be a 3 or an 8. Hm...

[@bones343]

@@steve470 That's actually pretty brilliant. Gold star.

[@jaeusa160]

Then should the Tau Sudoku have been titled "A Sudoku without a given whole number?!" ;D

[@LornaM2304]

Simon's pure joy at solving a great puzzle is what I need at the end of a difficult day, thanks as always for a top notch video :)

[@Pyromonkey83]

@5:00 - "Aaand... And I've broken the puzzle...Oh... Oh!" - I said literally EXACTLY the same thing at EXACTLY the same point in the solve. This was absolutely INGENIOUS setting by Daoud to put this in here. It completely messed with my mind when I shaded the region as even. It only took a few seconds to realize the solution to it, but that was one of the greatest "aha!" moments I've had so early on in a puzzle. It instantly boosted this puzzle from being a good one to being an absolutely stellar one, especially when the trick repeats itself a little later on. Absolutely fantastic!

[@chuckmo14]

1 given digit is basically a luxury at this point

[@blabla-rg7ky]

1 given digit is 1 digit too much. I mean, look how easy it is for them to solve these puzzles. I want to see steam coming out of their brains and collapse them on the keyboards after 3 hours of intense thinking. That's why I watch this channel, not to watch ex-champs doing colouring books

[@eclectichoosier5474]

@@blabla-rg7ky Why would you want to do that to Simon? It would be like punching a Labrador! All it wants is to play, and bring you joy; you can't be mad at that!

[@ethanderrick8486]

@@eclectichoosier5474 You've got to admit, you'd like a blooper where Simon spent a reasonable amount of time before inevitably failing. He'd become human!

[@yvke1996]

You guys uploading is the best part of my day!! Thank you!!

[@orangestories5025]

Without even putting in a digit, he says he has broken the puzzle. Simon you can make me laugh enough to wake up my family haha.

[@96Eko1]

Simon gülüşüyle bir ailenin içini ısıtabilir diyenlerrr

[@engilaru]

I started this puzzle by writing down each possible combination of digits to make primes. Was pretty handy.

[@stevieinselby]

Me too! I like to attack these puzzles fully armed 💪🏻

[@BlackMorc]

I did that halfway through, and it made it much easier!

[@moonglum101]

Yup, it's good to have a full arsenal going into these things ;)

[@julieenslow5915]

I am afraid i was more basic. i had to remember what a prime is. looked it up. blushed. resumed puzzle.

[@btf_flotsam478]

You can easily get around it by noting that the composite numbers are either even or divisible by 3 (the first composite number that isn't is 25, well beyond the sum of two digits). This leads to something similar to parity which can be abused to make it a lot easier. Edit: You could also just remember the two odd composite numbers in the range, 9 and 15.

[@Stephen-Fox]

Oh good glad to see you're being consistent with how Mark's standardized his colouring on odd/even parity. Watching solves with cool bits of logic in them is always a pleasure, due to just how much Simon appreciates cool bits of logic, even if you found that very same logic yourself.

[@1fosters]

Yes! Orange for Odd as they both start with O and Blue for Even because of Mark's new jumper.

[@rbush88]

@@1fosters It's funny how brains work because this colouring is viscerally wrong to me because I see odd numbers as "cool" and therefore need a cool colour like blue or grey and see even numbers as "warm" and so need a warm colour like orange or red. It's not at all logical but my brain keeps insisting!

[@georgelionon9050]

green for odd and blue for even... I'll stick to that coloring!

[@georgelionon9050]

@@rbush88 nah evens are cool.

[@cobalt3142]

This was the exact opposite of the coloring I used, so it was a bit mind-bending checking my answers lol

[@rustlingtrees8987]

Wow, that was a great one! I've been watching your videos so much lately that when I do sudoku, I talk to myself in British English (my native language is German). That must be a good sign.

[@Goofie_spielt]

Same here ...

[@8466849]

OMG! After 10 hours and a few restarts, completed without watching the video. Great puzzle and thank you!

[@jonahcomstock3061]

Simon, you're spot on. I was so proud of myself for figuring out the parity logic because I've been watching so many of your videos, but then Daoud went and pulled a fast one on us!

[@thomasbui6175]

Given how many Sudokus with no givens recently, is 1 given still a shocker?

[@vctrsigma]

We probably have seem some 0 number thermos that work, but arguably sandwich, killer, and little killer still have numeric clues given.

[@KyleBaran90]

I do quite enjoy minimalist puzzles, they feel a little more elegant.

[@Miss_Skooter]

it depends on the restrictions. In such a puzzle with this kind of restriction, you wouldn't normally find a single digit. Other sudokus like killers or thermos can work without a given digit more easily.

[@jaeusa160]

I think it's kind of intended to be a youtube deal, like "clickbait", just a kind of sad necessity to try to pull in new viewers. I got here from a "4 given digits" video myself, whereas other titles don't necessarily have that kind of pull for new anonymous viewers. So it may seem silly to us who watch already, but it is more gripping to a stranger than most other titles.

[@GroundThing]

My feeling is that no-given sudokus usually hide at least one non-labeled given which can be fairly easily discovered, where as low-number givens often require a bit more work to get something out of.

[@thedizzyexplorer]

The diagonal logic was a stumper! I was feeling very pleased with myself on figuring out the first steps of the opening... only to plunge into despair when I thought I'd broken the puzzle so quickly. First of this type that I've solved (apart from that clue with the diagonal!) I should give the puzzle hunt another go.

[@0manderijn0]

thank you for posting these videos each day! ever since finding you through the algorithm deciding everyone on youtube would be interested in your viral video I have watched every single video that has come out (and even gone back through many of your old videos). It's one of he highlights of my day!

[@cottagebirder]

Enjoyed this! Thank you Simon and Mark for the continued content

[@xDelejtx]

It's a truly beautiful thing watching Simon getting excited over cracking a puzzle

[@arturslunga3415]

Double amazement. The creator and the solver, both genuises. Most beautiful puzzle I have ever seen, solved by some sort of wizard (?).

[@tobermorywomble23]

That is an outstanding puzzle - one of the most fun ones recently. Brilliant choice.

[@ZachPeacock]

One of my favorite puzzles so far!

[@UnderAcheiver1]

The way the puzzle is constructed to show you the 1+1=2 along the diagonal as quickly as possible in the logic is astoundingly brilliant. The way it leads you from the alternating parity of row 5, up along the chain, across the border into box 1, where you immediately apply the parity idea you learned from row 5, and discover both of the cells must be odd despite the seeming contradiction, only to realize that 2 is a prime number is just *art, genuine, genius, art* .

[@DrMashirito]

PepperOni It’s brilliant. Clearly devised to get you to remember about 1+1 and place a couple of numbers. After that, seeing Simon make the same mistake and realisation doubles up on the joy.

[@salathiel2013]

For the first time ever, I found myself actually shouting at the screen! I was waiting for you to finish the 9's and 4's for forever! Yay! Great video as always, Simon!

[@JoeLindell]

I looped back to this puzzle recently, and it was one of the most brilliant examples of clever yet approachable logic I have seen on the channel. Thank you!

[@iwarx1]

What a nice mind-blowing puzzle. Sure I could not solve it in 100 years but it was pleasure to watch it)

[@Coyotek4]

I spent about 10 minutes convincing myself the puzzle was broken, started watching the video … and stopped *just* short of the key facet when it occurred to me what I overlooked. Continued from there and finally finished at 36:37. I gotta be more careful with certain assumptions for certain puzzles.

[@srwapo]

I worked myself into that corner TWICE. I got to Simon saying "ah!" in the video when it dawned on me.

Exactly the same happened to me, just as he described the prime number rule it dawned to me.

[@thesolarfutureenthusiast1102]

Oh my, we are treated to a starting digit, this one should be easy.

[@SegaJunkie]

22:48 for me. One of my favourite solves recently, mostly because I too had completely ignored the possibility of 2 being a valid sum... until looking at box 1!

[@iwarx1]

Thanks for your content guys! One of best puzzle channels in KZbin

[@jonbrowne8334]

I have only been following the Channel for just over a week! The giggles of joy from Simon and his unbelievable logical mind and mathematical skills are hypnotising. I have gone from being unable to solve an easy sudoku, to solving expert sudoku, within this short period of time! Thank you so much Simon! I still cannot follow your unreal logic, but the pleasure I get from your videos, is aesthetically appealing in a way I cannot comprehend! The new meditation?

[@Alansshows]

Whew! Took me an hour and 13 minutes. I'm always amazed how these guys know exactly where to look for the next step.

[@thomashjelm2928]

I'm up there near you with 1 hour 20 minutes. Felt really good to be able to solve it on my own! This was a fun one.

[@iwarx1]

Thanks for grate content guys! One of best puzzle channels on youtube

[@bobblebardsley]

Athos, Porthos and Aramis love Sudokus where you have to find the parity of the grid. They love placing a certain odd digit so much, they got the nickname... The 3 Must-go-heres.

[@TheGroatesque1]

Ouch! :)

[@paulcook2961]

Had to read that twice but well done! Pun of the day.

[@bobblebardsley]

@@paulcook2961 Thank you :D

[@cscatliff]

D'Artagnan hates this reference.

[@n8style]

That was terrible...I love it :D

[@Aedi]

id love to learn more about how one goes about doing this. i just want to listen to them talk about the thought process of making this. It looked daunting but was beautiful

[@regrettablemuffin9186]

I can’t believe you actually noticed and picked your colours based on my comment about my synaesthesia! Thank you! It was so pleasant to watch with the colours matching up to which colours I see as odd and even.

[@RichSmith77]

To be fair, there were quite a lot of comments requesting Simon do it the way Mark does it, for consistency. Not just yours. :-)

[@regrettablemuffin9186]

Richard Smith Ah, I didn’t see those. Well regardless I’m glad he’s doing it this way.

[@matthewscanlon1190]

proud to say I found this trick and completed the puzzle in 53mins. Playing soduko with you everyday for the last 100 days seems to be paying off ;)

[@Melissa-ms5kq]

Your joy finding the second pair of ones gives me reason to live

[@jaeusa160]

@4:00 It may come up later but there IS an exception to Odds+Evens having to alternate. As you said, two 1s can add to 2, which is Prime, and this can occur if the two 1s are diagonally adjacent in different boxes, which occurs in 2 spots at the bottom of columns 3 and 4 of the grid. r7c3 could be part of a pair of 1s in either of two possible directions. Edit: And I missed r3c3 which turns out to be a huge deal! Neat. Edit #2: Okay I'm blind there's like 5 possible times, but at least I noticed some!

[@jaeusa160]

Honestly, your Parity and Sandwich grid coloring solves are some of my favorites. Not only does it help you in your logic solving the puzzle but, as a viewer, it's also just aesthetically pleasing AND fun to follow along with. Likewise on the Miracle Sudokus with Knight constraints and such, where you color in possible locations for all the copies of a given digit, and end up pulling 1 lose thread of logic "And suddenly we've done all the 4s".

[@antalbojtos4413]

New member of the CtC team: Alexa. Simon's voice is way more soothing though.

[@brettaspivey]

Oh, come on now, 1 number is a lot for this channel

[@peterhowitt3861]

This is the most fun it is possible have - this was great. The logic was sublime

[@JasonIsTheManWithThePlan]

I did almost all of the even/odd parity before doing sudoku and I loved the logic behind it. It worked very well.

[@Oblivion776]

This was genuinely another beautiful puzzle. Quite enjoyed this one!

[@bitflippingmuckraker2148]

I'm waiting for a sudoku with negative 1 given digit.

[@vctrsigma]

Would a "liar" sudoku count as negative givens :-) (www.gmpuzzles.com/blog/2014/07/sudoku-liar-serkan-yurekli/)

[@teliots]

The fourth of july kzbin.info/www/bejne/q6Sol618jdmbeNE and undarbeyo kzbin.info/www/bejne/bZPZk3duZ9CSrbc puzzles both arguably have -9 given digits since you have to work out what the letters stand for.

[@killerkonnat]

@@teliots I don't agree. You have given numbers. You just don't know which ones they are.

[@teliots]

@@killerkonnat By that logic every sudoku has 81 givens, you just don't know what they are XD

[@cscatliff]

"One of the squares isn't even a digit. It's a picture of a squirrel. I'm not telling which."

[@frankgerolmo4129]

One of my favorite puzzles from this channel (along with the island/ocean one from a little while ago). It was both super difficult and super engaging at the same time, and every step felt more like I had worked something clever out than that I had missed something obvious. Super glad that I was able to solve it without help, but then again, it took me 4 hours, so take that how you will.

[@Zombie-lx3sh]

Thanks for fixing the colors, much appreciated!

[@kjardine06]

The pair of ones in boxes 1 and 2 had me switching shades around for a solid 30 minutes before I figured it out!

[@diegobolso2005]

The logic that leads Simon to place #7 in box 6 is amazing! It seems so easy once he explains it, but it seems to me so hard to realize on my own! That´s probably why I am still not ready for this level! As Simon says: "This is just gorgeous!".

[@TomOostenrijk]

You are pretty good at Sudokus, man. I'm in awe. I can't Sudoku worth a damn.

[@Nevir202]

Keep watching, maybe buy one of their apps, you can learn. I had maybe solved two or three easy sudoku’s in my entire life until I found this channel near the beginning of the year, now I’ve beat all of the puzzles, other than the new queen sudokus in the chess sudoku app, and a good chunk of their sandwich sudoku app.

[@Stephen-Fox]

As @Nevir202 said, keep watching. Dive into some of their older videos, maybe. There are a lot of puzzles showcased on the channel, some of them more approachable than this one, and both Mark and Simon go over some very useful techniques to improve your sudoku skills - Before starting watching the channel I struggled with anything that needed more advanced skills than being able to spot a naked single or a pair, now I'm comfortable some of the easier of the advanced techniques thanks to them. (I'm still hilariously bad at scanning, mind)

[@bryandedon7459]

I've never seen someone get so excited so often when doing a sudoku puzzle

[@stephenbeck7222]

The two 1s he pointed out is surely the break-in. Simon wondered about the middle of the cross in box 2 that had to sum with 4 unique digits to make primes, well by the time he got there he already had it down to either a 2 or 4 which are the only such candidates anyway (along with 1 which must be eliminated as already mentioned). That’s where I started and all it got me was that row 1 column 4 must be a 5 or 7 since those are the odds that don’t both pair with 2 or 4.

[@Scuuurbs]

I agree that the 1s are the break-in. I had the incorrect assumption that adjacent digits on a line must _always_ alternate parity and went back and forth between "R3C3 MUST be odd" then traveled to box 3 and reached a contradiction... then started in box 3 and traveled up to box 1 to reach the conclusion that R3C3 MUST be even... then it finally hit me.

[@alienrenders]

I found the 1's right away. Didn't help me any. I'm just too slow at these.

[@joshd2538]

I saw the 1+1 trick early on but wasn't confident enough in my skills to be sure, so I checked to see your solution. I checked again when I had to do the 1+1 trick again. Thanks!

[@karlwaugh30]

Managed to do it in 37 mins without watching the video. I had thought I'd made a mistake with that double one and has to rewind myself and go again from the other angle. Had to stare at it before it clicked. Very fun puzzle.

[@weikel2000]

Loved the puzzle. Once again the even/odd parity was a blast, and I appreciated that blue was used for even and orange for odd this time, though I nearly switched my coloring because I expected that it wouldn't have changed for the video, but then I decided that it might confuse me and I'd rather be confused watching the video than doing the puzzle. I didn't figure out the 3-9 pair in left center square on my own, I was glad when it was figured out early on in the video, that was the first thing in the video that I hadn't already found on my own and it allowed me to finish the puzzle, but I was staring at for a good half hour at the point before I gave up to see what the video could tell me, and I was kicking myself when I saw that because I spent so much time staring at that triple. I did run into the even/odd problem in the first square, though I did it differently. After figuring out the square 4, instead of going off the center box up to square 2, I jumped straight into square, so I got that correct, but working backwards I run into the issue as I got back to the center box, but I immediately recognized that I could do the consecutive odds in the proper spot. I immediately looked to see if the trick could be repeated before I started figuring out more of the even/odds, just in case it would break the puzzle again.

[@cxeazn]

Solved it in 41 minutes with no aids! Usually I'm unconfident and keep the solution open on another tab so I can check periodically to see whether I'm on the right track, but today I decided I wouldn't, which makes me that much prouder of myself :) I also got stuck on the 1-1 pair in R2&R3, but I happy I pressed on instead of giving up!

[@fofotre8361]

I find really satisfiying to see the full-colored grid at the end.

[@AEPMUSlC]

At first I was just staring blank and with completely vacant mind at the screen for at least 20 min but when I realized the odd-even relationship and how some of the numbers were more restricted than others the coin dropped and the solve became sooo satisfying and smooth.

[@kamarulaqira3271]

All these sudokus are so intricate with their solutions. Can we have a video on how to create such sudokus? That'll be awesome!

[@KnightTobyas]

I think this is the first new gimmick that I figured out without watching the video. It still took me over two hours, but I loved figuring out the relationship between even and odd numbers on my own.

[@deleetiusproductions3497]

I don’t even know how many times this already happened

[@shocklab]

I found that writing down the graph (in graph theoretic terms) of the numbers 1 to 9 with lines joining all those which add to a prime helped a great deal. It helps to see the possibilities at the junctions.

[@dragonborne3277]

2:15 on 3rd attempt after breaking it twice. I love your phrasing; rather than "What am I missing?", you say "What does it want me to see?".

[@balkthor]

These are some prime levels of excitement from Colin.

[@RandomBurfness]

I solved this a day ago or so and Simon's solve path is way, way more elegant than mine!

[@AMajesticHobo]

Fantastic puzzle, beautiful solve.

[@toddbiesel4288]

That moment when you think that you've broken the puzzle... and then laugh... is when I paused the video and knew exactly what the problem, and subsequent incorrect assumption, was.

[@maaalene]

I concluded the 4 in r2c5 right away because it's the only digit that has four possible combinations for prime numbers up to 17. But then I got stuck and came back to watch you solve the puzzle with this neat even-odd technique.

[@thatpuzzleguy]

I got the top 1-1 smoothly, but then had a moment of panic when I deduced odd numbers in another linked pair. I don't learn, apparently.

[@89roddy]

What a nice puzzle! It was fun. I wrote down the possibilities for two digits to sum a prime so I can look at them. And while solving I coloured the evens and the odds. That helped me a lot.

[@eliaskar5084]

Let's get cracking: 3:00

[@1989someguy]

As usual, I loved watching you solve that. The puzzle itself was a little too math heavy (don't get me wrong, I love the maths) but I don't think that I know prime numbers like you do. Still, I could follow along with everything that you were doing, so I still enjoyed it!

[@ShirtsAreRare]

Amazing puzzle! I really enjoyed that.

[@RescueMichigan]

Great puzzle. I missed some sudoku in the midgame and ended up spending way too much time experimenting with parity in the lower-right to place an odd number in R9C9... only to realize it was was 9 by sudoku the whole time.

[@ryfors]

Hello! Thank you for you wonderful videos, I'm a big fan of both your channel and you apps! I was wondering if you could add stronger colors to the app? As a colorblind person the lines in this sudoku mesh with the color you choose (I think you said it was blue?). I have a weaker version of the colorblindness so I can manage, just wanted to ask for all my fellow people who struggle with soft colors!

[@Tiger21us]

I loved this one! Was able to do most work on my own too! Very fun.

[@seanmcdonough2683]

Still on First step of puzzle "... and I've broken the Puzzle". Nice to see Simon experience the same thing I do on almost every single one of these.

[@chess10x]

I usually take my time and solve these on my own then go back and watch the video. It always takes me much longer. This is the first time that my logic was incredibly different from Simon's. When I watched him solve it, I couldn't help but think how interesting this puzzle is because you can truly approach it different ways.

[@cyangoose]

Thank you for making the odds and even those colors. I’m not sure why, but that really bugged me for some reason when it was the other way around a few videos ago.

[@Nevir202]

Thanks, really appreciated the coloring scheme today.

[@SgtElev3n]

Kinda hard to see the gray lines on colored squares tho

[@Nevir202]

Elev3n True. Their software could benefit from the ability to automatically change lines to white when a cell is shaded. 🤷‍♂️

[@DanB-sh3wt]

I love how excited Simon gets when he sees a tiny new piece of logic he can use.

[@BlueCyann]

Yeah I had the same moment of confusion in box one, not a minute after deciding that yes, parity would in fact be a good approach to solving the puzzle, given that you could never get a sum of two. Good times. Unfortunately I made a mistake somewhere early that didn't break the puzzle for a very long time and was in no mood to start over.

[@jrbb494]

Thanks for making me smarter.

[@theatog]

Can't do the "which odd even pair had common numbers" in my head, so started with an quick excel sheet to figure that out. That took me a bunch of time. Twice I made an unrecoverable mistake and had to restart. Finally got it the 3rd time at 28:28. But added all the wasted time before I think I spent easily 2+ hours on this. The "careful me", if it could ever exist, could've done much better.

[@dcc1165]

This is a great puzzle. Although the time is listed at ~30 minutes, it's taking longer than that because I have to keep rewinding to before the interruptive ads show. Is there any way with these videos you could put the ads at either the beginning or end or have graphical pop-up ads instead? It's very frustrating to have train-of-thought interrupted like that.

[@ethanderrick8486]

I didn't get ads halfway through... I think they purposely don't put mid-rollers because of that (I certainly never have them) so I'm very confused about your experience!

[@dcc1165]

@@ethanderrick8486 I didn't think about it, but I believe reloading the page helps. KZbin inserts ads in whatever way they choose, I guess. You know, cuz Google is struggling these days, what with all this remote computing going on :).

[@Articision]

13 minutes in: "Maybe I've gotta do some sudoku" Gotta love this

[@LightDhampire]

When 5/6 was placed in box 4 at 23:34, only one of those could be even. along with r1c3, this determined both r8c3 and r9c3 as even. For my solve, this let me determine parity of the rest of the grid, After which, the even digits resolved themselves, followed by the odds.

[@fuji2086]

“And I’ve broken the puzzle. Oh.” Same here, Simon!

[@fuji2086]

Also, this did end up being quite a bit easier than I expected. Fun puzzle.

[@undergroundmonorail]

5:00 "This one's sticking out, that's gotta be even" Seeing as they're in different boxes and rows, could they not both be 1? edit from 10 seconds in the future: Oh, shame on me.

[@JuanMataCFC]

i realized it didn't need to be even as i was solving, so i guess i didn't make that "mistake" ... but that was to my detriment! because when i (much later) marked that cell as odd, it took me a while to notice the two odds next to each other and realize they both had to be 1!

[@stevieinselby]

@@JuanMataCFC Like Simon, I initially marked assumed it was even, then broke box 1 in almost exactly the same way, furrowed my brow for a few moments in puzzlement, then figured out that it had to be two 1s. I was very pleased with myself for that!

[@Zhon66]

@@stevieinselby I came at it from the opposite direction - I started marking parity without being sure which color was even or odd, then used the loop in box 1 to confirm that the last digit must be odd, circled back to row 5 with my newfound knowledge and went, "...wait a minute."

[@richardfarrer5616]

My solve path was almost identical to yours, including the belief I'd broken box 1 and my delight in realising that there was a way out.

[@justinwhite2725]

@13:00 I've been thinking from the start that you must be able to k ow what those 3 on the line are in the bottom middle box. There can't be that many prime numbers you can make without a 3 - especially now that you know you've got 2 evens and an odd.

[@victoriam6569]

Such an enjoyable puzzle!

[@orkedar8786]

Started the solve, figured that theres a mistake in the rules because of the odd/even constraint at the top left. Came back to see how Simon solved it. All I needed was for him to say "this is beautiful" instead of "this doesnt work" for me to realize what it was

[@AndreAy1975]

Solved it with much help from the video.

[@Stephen-Fox]

46 minute solve for me - Surprisingly quick given how long the video is to solve a very enjoyable puzzle.

[@killerkonnat]

I figured out the odd/even color parity immediately, but I had to retry it 3 times because I thought I had ended with an impossible situation, until I finally realised the prime 2 is actually possible when crossing boxes diagonally!

[@MistaUnicorn]

Why is this the 4th video of his I’ve seen today? I don’t play Sudoku. I don’t even really like Sudoku. But I can’t stop watching these. I need help.

[@noiplah]

Love it! Fun puzzle, fun solve, fun video :)

[@BryanLeeWilliams]

Love the addition to your apps. I recently changed phones and lost all my progress.

[@Emma-rw8yo]

Needed some help at the beginning to understand the core even/odd logic and a few or the first steps, but I was able to complete these puzzle on my own after relatively quickly :D