The Best Palindromes In Sudoku!

[@borkvanderbeldt]

I am Sebastian, thank you very much for the well-wishes, you made my birthday.I have made sure to thank Elizabeth properly.

[@Dodrebur]

There was a small logical error, but it produces the same result at the same time. In Box 8, Simon neglected the possibility of the black dot being a 12 pair (dark green would be 134, but 1 would be in the middle, forming a 234 Renban), but the logic is only slightly different. It creates a 1234 quadruple in row 9 which forces R9C5 to be 6, rather than a 123 triple forcing R9C2 to be a 4. The difference is negligible, but strictly speaking, the possibility should have been accounted for. Great video! :)

[@arandommonth765]

i don’t think the 123 triple even needed to be said, the B in R9C7 makes R9C2 a D digit which must be 4 from previous pencil marking

[@twalander]

@@arandommonth765while you are correct; IMHO Simon ruled out the 1 from C5R9 way earlier than he knew there was a B in R9C7, so it just makes it a lucky shot…

[@baumundallesandere]

Thanks for the explanation :)

[@MattYDdraig]

26:34 When Simon asks "What is beauty...?" in a puzzle, how appropriate that it is followed by solving this masterwork. I'd agree with Simon that the beauty doesn't come from anything in the degree of difficulty but can come from so many places. The joy of an "a-ha" moment, or the elegant combinations of seemingly unrelated rules colliding in way you never saw before. The sparsity of clues that somehow provide the perfect information to complete a solve, or the bizarreness of a wrogn puzzle finding order out of utter chaos. And thank you CtC for providing us with so much of this puzzling beauty.

[@Orenotter]

With arrows we get underway. With palindrome logic we play. Dots and renbans are fun. When the whole thing is done, "And that's the puzzle." I say.

[@DrZZZee]

Surprisingly, Simon somehow missed a much less convoluted deduction: simply remembering that a bottom purple digit must appear on green palindrome, therefore box 8 renban+black dot can never be 1234, and the only arrangement that works for the arrow is 126. The rest unfolds in a very similar fashion.

[@TheEricthefruitbat]

Missing the easy way, and backing into a convoluted way, is standard Simon.

[@Acylumgaming]

I would even add to the difficulty discussion that if some deduction is too hard and takes like 45 minutes of hitting your head against the wall to get it, even if the logic is pretty all you're thinking afterwards is "Thank god that's over."

[@emanuelfer456]

Its why for me the 2-3*is normally on the spot. A good 20 - 30 min of logic and satisfying solving without it being too easy or too hard

[@martysears]

Brilliant puzzle Nell, very happy this got a feature. Awesome interactions between the palindromes, renbans and arrows. And very cool and surprising that the contents of the palindromes all ended up being different, and not filled in til right at the end. I agree that this is one of the most interesting palindrome puzzles I have seen.

[@davidrattner9]

Coming from you..I constantly cherish what you say about other puzzles and setters!!

[@dkamm65]

After getting the red digit in box 1, you could have deduced red was 9. Red could be placed in column 2 in row 5 as it can't be on the palindrome, then it could also be forced into column 7 in box 6 as it couldn't be on that palindrome either. That leaves only one place for it in box 9, in the arrow's circle, forcing it to be a 9.

[@chipsounder4633]

Very elegant ❤

[@Dinandino]

Doesn't this give two possibilities for the red digit? Either row 7 or row 9 (both column 8)? (from which you can show that row 9 column 8 is a 9 , but not neccesarily red)

[@jasminski08]

This comment makes me feel so seen ❤️ this was the deduction I used and I was surprised that Simon didn't use it! I bounced the red around the grid and limited it to either position 2 or 8 in box 9. It doesn't prohibit red from being a 6 necessarily, but it does mean that regardless of whether red is 6 or 9, the arrow total in that box has to be 9. Because of the 1 on the box 8 Renban that forces the 621 triple on the arrow.

[@jasminski08]

I hope that made sense, I'm a long time viewer first time commenter but it's exciting to read through the comments and see how others achieved the solution. It makes me feel validated as a sudoku novice, especially when Simon has a very different solution path

[@crashtextdummie]

It's possible to show that R9C8 is the red digit before resolving any of the arrows (via R5C2 being red, forcing red into either R4C7 or R6C7). The situations in boxes 8 and 9 resolve cleanly from there.

[@saiyanprince989]

Yep. Simon being Simon. Starting a logic tree and then promptly forgetting it.

[@stevieinselby]

I think Simon had a lucky break in this one ... I can't see why r9c5 couldn't be 1, with 2 on the dot and surrounded by 3-4 ... that's a valid renban line with 2-3-4.

[@Happyjew666]

R9C5 could have been 1, until the 4 is discovered in Box 7.

[@stevieinselby]

@@Happyjew666 But the 4 in box 7 was discovered by using a 1-2-3 triple that wasn't justified because two of those digits could have been 4. Sure, you can go another step further and then you've got a 1-2-3-4 quad, which puts 6 into r9c5 but there's at least two steps there that Simon skipped by not considering all the possibilities for box 8.

[@Happyjew666]

@@stevieinselby r9 in box 8 must have a 1 in it. This rules out 1 from R9C2. The 2/3 in R8C5 must be in r9 in box 9, and thus must be in R7C2. That leaves only 4 in R9C2 (also due to a virtual 123 triplet).

[@RichSmith77]

​@@stevieinselbyDoesn't he still have a 123 triple in dark green + r9c7? If r9c5 was 1 (which I agree he missed pencil-marking), he still had 2 on the peak of the renbans and 3,4 either side of the 1. Along with 'B' he'd just marked in r9c7, that still uses 123 in those four cells along the bottom. (In fact, it's immediately broken because it's actually a 1234 quadruple along the bottom leaving no fill for r9c2).

[@pixllo]

I'm such a nincompoop. Took me nearly 20 minutes just to understand the break in even though I had been staring at it in the face. It had such a simple yet sophisticated elegance I had to come comment here and thank the setter.

[@Paolo_De_Leva]

Unquestionably *cosmic class* geometric interations between clues. Thanks a lot to those who recommended this beauty and to Simon for featuring it.

[@glum_hippo]

This puzzle is soooo retro, but not in a bad way. Some of this logic hasn’t been seen on the channel in some time. Thanks Nell!

[@bethanyhunt2704]

I loved the way the numbers keep chasing each other around the grid. 10/10

[@Rubrickety]

I loved this puzzle! Lately I've been getting a little exhausted trying (and often failing) to solve puzzles with brain-breaking rulesets. I sometimes miss the "old days" when more of the CtC puzzles featured familiar elements used in surprising ways.

[@raysouth1952]

Lovely puzzle. I lucked out quite early by tracking a particular cell around the grid (not Simon’s 23 pairs) which resolved the arrows. From there it was a smooth path to the end. Very enjoyable.

[@GlaucoHass]

You see Simon is having a good time when he knocks his hair from well behaved to some variation of a street fight after a pub backgammon clash.

[@chocolateboy300]

I finished in 56 minutes. The geometry of the renbans on the palindromes, and therefore the arrows, was a very cool break-in. It was just as cool finishing the rest of the puzzle. Great Puzzle!

[@emilywilliams3237]

Very, very interesting. I might put this one on the "try this sometime with the video at hand" list because I doubt I could get very far on my own. But I loved watching you solve it, Simon (and you made it under the time limit, clearly).

[@tyrgannusgaming6657]

I approve of this palindrome layout

[@Raven-Creations]

At the 32 minute mark, where you're apologizing, you could have noted that B cannot be on the arrow in box 9. Since it must contain one of the 23s, it must be A in R7C8. This puts A on the renban in box 8, along with 1 and B, making the renban a 123, with 46 in R9C5. This was very clever setting, and that bent renban really mixed things up nicely.

[@anaayoung9142]

This one was amazing! Great that I could solve almost full by myself (minus the start 😅). But with some colouring I could find the red digit before the little ones 🤔 (I did have the 23 in box 9). Because the red can't be on the palindrome at box 4, so it is at R5C2. This make the red at box 6 eitheir R4C7 or R6C7. Making the red the R9C8 in box 9! (Because it can't be on the palindrome there eitheir!). Thanks for the solve! 😊

[@michaelandersen-kk4fc]

almost missing the dateline, is the main source of excitement in Simons life

[@douglasmagowan2709]

Where you get stuck between minutes 30-35. You almost had hit when you placed red in box 1. Where is red in Box 4? There is only one place for it. Then where is red in box 6 and box 9? And with that red must be 9.

[@RichSmith77]

This was my path too. I thought it was neat that it didn't matter if red was 6 or 9, it forced the circle on box 9 to be 9. If red was 6, then it had to go in r7c8 in box 9, making the circle 9. And if red was 9 then it had to go in r9c8, so again the arrow circle on box 9 was 9. Edit: Although I still had red as possibly being 6 and in r7c8, which you seem to have ruled out? I did that later.

[@sherifkkvtm]

This is how i break into it from 25:10. marked 69 orange in Region1 R1C3 then Region4 R5C2 (using Simple sudoku and paliandrome lines). Then in Region6 it will be in column 7. So in region9 it will be in R7/9C8. We know region9 arrow must have 2 or 3 (126 or 134) and it must be in R7c8 (row 8 already have a 23 pair). Orange is not 2/3. so it is in R9C8. Commen digit is 9 so orange is 9.

[@frankjiang1857]

Finished in 21:45. Lovely logic here to differentiate slightly the quadrants of the puzzles to make the puzzle solvable. I think for me a name which more mirrors the way to solve it is reflections and refractions. Fun puzzle!

[@koulchin]

At 12:00, the easier way to see it is to ask where the digits on the renban in box 2 go in box 1. They cannot go in row 1 by sudoku and they cannot go on the palindrome because they would be reflected into box 2 and conflict. So they must go on the arrow.

[@awilliams1701]

This palendrome configuration is in the CTC app. For the longest time I didn't understand the puzzle. I'd just bifurcate. But then it occured to me what they were actually doing. This lightbulb moment that Simon shows at the 9 minute mark cut my times in half or more on that puzzle. lol

[@dolf370]

Sorry for missing your B-day yesterday. So a belated congratulations. May you solve sudokus for many a decennia yet.

[@smylesg]

19:14 Purple mountain majesties (below) the fruited plain.

[@inspiringsand123]

Rules: 05:25 Let's Get Cracking: 07:53 What about this video's Top Tier Simarkisms?! Bobbins: 2x (23:18, 27:53) Three In the Corner: 1x (07:25) The Secret: 1x (39:30) And how about this video's Simarkisms?! Ah: 14x (07:07, 14:01, 14:01, 18:14, 21:50, 23:00, 24:50, 26:28, 30:28, 34:51, 36:18, 38:17, 40:21, 45:30) In Fact: 6x (03:28, 03:28, 10:26, 14:42, 16:40, 27:14) Clever: 4x (36:06, 48:08, 48:43, 48:45) Beautiful: 4x (03:48, 14:05, 14:05, 48:05) By Sudoku: 4x (35:38, 40:58, 46:40, 46:43) Cake!: 4x (02:12, 02:12, 02:23, 04:42) Weird: 4x (10:43, 10:43, 11:05, 35:16) Goodness: 3x (10:31, 28:49, 47:38) The Answer is: 3x (14:19, 38:46, 39:11) Brilliant: 3x (01:47, 03:21, 47:57) Gorgeous: 3x (39:06, 43:06, 43:13) Hang On: 3x (01:21, 15:55, 44:52) Obviously: 3x (00:35, 15:14, 26:54) Sorry: 2x (11:05, 32:06) Lovely: 2x (16:01, 42:12) Shouting: 2x (04:22, 04:34) Pencil Mark/mark: 2x (35:43, 44:36) Symmetry: 2x (24:43, 48:48) First Digit: 1x (37:22) Come on Simon: 1x (27:53) Bizarre: 1x (36:55) Masterpiece: 1x (04:54) QED: 1x (42:25) Marries Up: 1x (29:40) Nature: 1x (02:45) Most popular number(>9), digit and colour this video: Twelve (3 mentions) One (102 mentions) Red (21 mentions) Antithesis Battles: Even (4) - Odd (0) Black (17) - White (0) Row (19) - Column (9) 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!

[@JohnGisMe]

Thank you for this.

[@oliverwhiting7782]

The video's only been up for a minute and you've already analysed the whole thing! I'm really curious, how does the bot watch the whole video so quickly?

[@nestoreleuteriopaivabendo5415]

​@@oliverwhiting7782 Maybe he's a patron and watches before everyone else. Or maybe he is Simon himself.

[@Situayo]

​@@oliverwhiting7782i guess it analyzes the transcript

[@JohnRandomness105]

33:20 Continue with red, placing that color around various blocks, specifically 4, 6, and 9.

[@jonathanwest6266]

Love how Simon's logic is always back to front - easier question, where do the renban digits go?

[@chipsounder4633]

Absolutely gorgeous puzzle.. im going to watch this many times.

[@Swisswavey]

Nice puzzle, a relaxed 25 minutes. Lovely logic and a neat denouement

[@tBagley43]

1:09:55 really cool how the different lines in the puzzle work together :)

[@iabervon]

In boxes 1 and 2, rows 2 and 3 have 3 digits in common due to the palindrome. If they had a fourth digit in common, that would put 4 digits in row 1 in box 3. So all the digits on the arrow in box 1 must be in row 1 in box 2.

[@sagov9]

I think there was a logical mistake here though, after finding the option for 134 on the arrow with 4 in the middle on the black dot, Simon does not ask himself if there is another option with the same digits, ie. 1 in the middle is possible. Therefore the 1-A pair Simon finds around 36 minutes in was not validly deduced.

[@bethanyhunt2704]

30:15 Aah, Simon should have kept going with the dark green digits. There is definitely something wrong with 1,3,4, because I assumed it was that, and soon discovered it doesn't work!

[@chaosredefined3834]

I think I missed something. How did we ignore the bottom renban being 324 or 423, with the 1 being on the middle and the arrow in box 9 being 8-134?

[@derekjc777]

You are correct. 134 in row 9 cols 4-6 doesn't have to be 143/341 with 123 on the renban, which is what Simon chose. It could be 314/413 with 324 on the renban. Fortunately Simon chose the correct option.

[@Happyjew666]

It was a (fortunate) accident on Simon's part. However, as soon as 4 is placed in Box 7, it resolves R9C456.

[@MyriamTT]

Palindromes, how I've missed you !

[@thejuggler42]

What a fantastic puzzle! Glad I paused the video to solve it myself before watching.

[@Hakucho64]

From 25:44 onwards, if Simon had only done Sudoku on As and Bs in box 9, he would have cracked it wide open a lot earlier.

[@michaelmatter1222]

Simon if you are in a time pinch you can always set Playback Speed to 2x and you'll solve the puzzle twice as fast 🧠

[@jinkela7295]

The reason why the renban in box 8 isn't a straight line (like the ones in boxes 2 4 and 6) is that if the renban in box 8 is straight, the 2's and 3's in boxes 1 4 6 and 9 will form a deadly pattern.

[@chipsounder4633]

Spotted something easier at 19 mins in, where is green in column 1. Even easier is red in row 1. Well placed scotoma.

[@chipsounder4633]

Then ask where is red in column 2 as red can not go on the palindrome then box 6 then box 9... Red is 9.

[@stonehornet1171]

Amazing solving Simon! I feel like you were extra sharp today

[@malvoliosf]

I will forgive you, as a Brit, for not calling it “purple mountain’s majesty”.

[@themuffin437]

33:30 for me, a puzzle with a really satisfying break in

[@Kirbyfan87827]

Finished in 36:48 with help from the video.

[@henriknobinder7395]

I agree completely with your thoughts on difficulty and beauty. I posted something similar in a comment on one of Mark's more recent videos, though I used the words that a puzzle should aim to be fun and interesting rather than beautiful. In the end, however, we both probably mean the same thing.

[@josephbentley1300]

33:57 for me, thanks for the puzzle as always

[@PathOfShrines]

Marvelous puzzle; really neat logic. 33:41; very happy with that solve.

[@RealCadde]

How long are you going to ignore the LAST step of sudoku on A and B? Ask yourself the question, where is B in box 9? It's not in light green because the B at R8C5 eliminated that possibility. So B is in row nine of box nine. Therefore, B is NOT in R9C2. Also, ask yourself where A is in box 9? It's not in light green for the reason R8C3 sees all of light green via the palindrome. So A is either in row nine of box nine, which would make an AB pair (equivalent to a 23 pair) OR it's in R7C8. Well, if you formed an AB pair in row nine of box nine, how would you now get to a sum of 8 or 9? If you can't use either 2 or 3? Your options were 134 or 126. You most definitely need a 2 or a 3 in dark green! In any other case, since R7C2 IS B in that box because it can't be in row nine. You have a 23 pair in box 7 making R9C2 a 4, which is D. You so often do this, you make a deduction that gets you half way there, only to then abandon that logic train RIGHT before it's about to pay off!

[@dempiz]

Perfect difficulty level on this one. A bit thinking required but also very doable.

[@thebitterfig9903]

Fascinating puzzle, tricky one but was able to grind through it.

[@wypmangames]

At 36:28 i noticed the b from box 3 and 8 making a + by sudoku, forcing box 9 b in a corner... butt then i realised it couldnt go on the palindrome (row 7) cus its copy would neighbour itself, forcing box 9 b into the bottom and box 7 b d pair to have b at the top, and d at the bottom (2 3 4 pencilmark and we know d = 1 or 4, giving me the first digit before simon did (though it might have been spotable sooner)

[@xWinGLP]

at 46:07 when simon did put in the 1 digits in row 1 and 6 shifts... intresting

[@Gonzalo_Garcia_]

11:18 for me. Great puzzle!!

[@stevenape377]

Loved it, a very interesting puzzle! I found it tricky but doable, just the right level.

[@andremouss2536]

Why didn't Simon consider the 23 pair in row eight ? Since the arrow in box 9 must be 134 or 126, it contains a 2 or a 3 and that makes R7C8 a 23, which must be A.

[@piarittersporn]

Fantastic and very exciting puzzle.

[@bait6652]

Nice quick one when u discover what ur suppose discover. Love designs wheref u dont have to fill out or use One or 2 digits...this might even go 3. Never would have thought 578 would make a color group for me

[@Merdock19]

Have not finished the video yet, but how is r9c5 not able to be 1? If the set of green cells is 134, then it seams to me that the purple line in box 8 could be 4-2-3 with a 1 in r9c5. So it seems like he should mark that cell 146

[@RichSmith77]

It could have been. I don't think it would have changed the solve path, though. He should still have been able to conclude r9c2 was a 4 at around 37:20, even with 1 pencil-marked as an option in r9c5.

[@Merdock19]

@@RichSmith77 I agree. Where I was at when I made that comment 1 was still an option, but when he put down the digit 4, that forced r9c4-6 to be a 126 set with 6 in the middle.

[@RichSmith77]

​@@Merdock19There's a comment by @DrZZZee below that points out the bottom purple digit in box 7 (r9c2), a 1,2,3 or 4, had to appear on the palindrome in box 8. This rules out any of the "2 above 134" options for the bottom of box 8, and forces it to be the "3 above 126" option much earlier. Pretty neat. Not something I spotted.

[@Merdock19]

@@RichSmith77 that's a good catch, and not one I would have noticed either

[@srwapo]

46:43, neat puzzle! For some reason, I neglected to pencil mark 1s on the black dots and broke my solve TWICE.

[@randysavage1011]

Sir, I demand, I am a maid named Iris. Was it a car or a cat I saw? Yo, Banana Boy! Eva, can I see bees in a cave? Madam, in Eden, I’m Adam. A man, a plan, a canal, Panama! Never a foot too far, even. Red roses run no risk, sir, on Nurse’s order. He lived as a devil, eh? Ned, I am a maiden. Now, sir, a war is won! Evade me, Dave! Dennis and Edna sinned. Step on no pets!

[@Rach881101]

50:46 for me. Nice puzzle!

[@prodigis.]

19:34 very pretty cycle around the perimeter

[@dkamm65]

I think Simon missed an option for the renban in box 8. At 24:19 when he's mulling over the possibilities for R9C5, why couldn't it be a 1? It would have a 2 on top and a 3/4 in the wings.

[@xyzzyx7812]

a rare mistake by Simon. R9C5 can also be 1 without any further deductions.

[@ericveneto1593]

C is different from D. Knowledge bomb. :)

[@MarkWiseTechno]

42:14 for me on this one. Very fun!

[@KveruLars]

Where is B in box 9 is an easy question he should've asked the moment he deduced B to be either 2 or 3

[@Hakucho64]

Same with A. As soon as he lettered the 2s and 3s as A/B, he should have worked his way around the grid, but sadly he distracted himself.

[@Roblilley999]

33:33 all the 3s (not in the corner)

[@six_5000]

Solved in 60 minutes on the dot 😮 🎉

[@user-ld9tf4td8s]

There are a lot of palindrome names. You mentioned Hannah, but there also Anna, Elle, Eve Otto, Bob, Ada, Ava, Asa, Navan, Aviva, Jalaj But there are also lots of words that are palindromes. mom, dad, tot, sis, nan, pop, nun, madam, ma'am, yay, wow, pep, bub, bib, gag, gig, sees, peep, toot, noon, did, dud, deed, civic, deified, refer, rotor, rotator, kayak, racecar, level, reviver, tut-tut, deked, redder, radar, sagas, tenet And then there are full sentences Egad, an adage Dammit. I'm mad I did, did I? Top spot Yawn a more Roman way We few Was it a cat I saw? No lemon, no melon Some memos Don't nod Puff up A butt tuba Now, sir, a war is won He lived as a devil, eh? Madam, in Eden, I'm Adam A man, a plan, a canal. Panama Step on no pets Top step: pet spot A Santa at NASA A Toyota Not a ton And let's end with a few for all the numberphiles Never even Never odd or even Sums are not set as a test on Erasmus Stressed desserts (chocolate cake)

[@surferriness]

12:45 nice

[@NeilGirdhar]

Relly fun puzzle. 29:34 for me

[@turbochrist]

Didn't we know that D was 4 in box 7 for quite a while?

[@jonathansim7148]

Sorry Simon but I had to laugh; you appear to have turned into Mark, lol.

[@Squishy3757]

When you put the 3 in box 8 the B was obscured.

[@RoderickEtheria]

Solved in 33:33 without help.

[@sharath123sk]

ABD in purple is the greatest version of alien hitter Only cricket fans will understand this comment BTW thanks for having ABD, I miss him so much😭 I’m an Indian but I miss ABD😊

[@nicka3697]

Happy unbirthday Simon

[@TurquoizeGoldscraper]

31:08 for me.

[@_-_-Sipita-_-_]

13:00 for me.

[@sacredsock8031]

damn, lost again. Did not expect that as the first digit.

[@Timlagor]

Definitely a 4 * difficulty opening in my book

[@ericveneto1593]

Is he claiming the bent remband line ISNT a remband line?!

[@RichSmith77]

I don't remember hearing him say anything like that. From 18:20 for the next minute he's talking about the renban in box 8 and the fact it's not like the renbans in the other boxes. He says it's a "purple hill, and a purple hill is not the same as a purple plain". Unless there's another point in the video I'm forgetting, I don't think he ever claims it's not a renban?

[@robertcousins2274]

23:34 For me

[@LednacekZ]

31:13 for me. horrible solve. i got the symmetry of arrow and non-palindrome quite fast, but for some stupid reason i did not think it would apply to the other 3 arrows too. wasted at least 10 minutes.

[@Queue28]

Lovely palindromic time though.

[@Pritchie45]

23 minutes

[@johnosullivan675]

I've never got here in the first minute before now.

[@AndreAy1975]

Solved it without any help from the video.

[@hrbattenfeld]

Kind.

[@theredstoneengineer6934]

24:02 for me