Thanks for solving my puzzle! I had the break-in idea for a while, but hadn't come up with anything past that until recently. I'm really pleased with how it turned out in the end!

@David_K_Booth

23 күн бұрын

I really enjoyed the break-in - such a witty touch. Well done!

@Timlagor

23 күн бұрын

I like it but it's fiendish

@Paolo_De_Leva

22 күн бұрын

Crazy break-in‼🤣 A cosmic effect obtained with a trifling, minimal twist of a standard ruleset. And beautiful logic does not stop there‼ I bet this beauty will be on volume 3 of *CTC Greatest Hits.* 👏👏👏👏👏👏👏👏👏👏👏 As I explained in a separate comment, Mark's SET trick can be simplified if you use a simple permutation of *Phistomefel's theorem.*

@alanscott8245

22 күн бұрын

Yeah, this might be my favorite set break-in of all time. Very fun puzzle.

Your laughter when you discovered the results of your SET elimination was so contagious - I rewatched that minute just to enjoy it again. The whole video was lovely and quite fun - thank you, Mark.

@David_K_Booth

23 күн бұрын

I had started the puzzle before watching the video, and I had a very similar reaction: "Something's gone terribly wrong. What on Earth did I do? Aha! No, it's gone terribly right!"

@CraigBeere

22 күн бұрын

Same here. It really is a beautiful breakin to the puzzle.

@erickehr4475

21 күн бұрын

@@David_K_Boothi love the phrase “Something’s gone terribly right”!

I did the same SET as you three times, and couldn't see what I was doing wrong. Gave up in the end and watched you do it. Proceeded to bang head on desk!

Just before 17:00 there is a simpler analysis of rows 1 and 9: The row totals to 36. If you subtract the two X-pairs worth 10 each, you're left with 16 total for the remaining cells, which consist of a zero, the circle of an arrow (max 8) and cells that total to the circle of an arrow (also max 8). To reach 16 both these arrows must sum to 8 and the rest falls out easily.

@bait6652

14 күн бұрын

Been trying to figure out the non setrepl method ...thanks for this

Amazing! Ive never seen Set Theory result in zero.

36:27 Truly one of the best openings I've seen. The whole thing was great, but the break-in was simply awesome.

Wow! That's one of the most amazing break-ins I think I've ever seen on this channel.

11:59 It is actually the same kind of reasoning as an "alternate phistomephel ring". You take two rows and two columns against four boxes. Just move them around and you will see they are the same.

I think this may be one of my favorite break ins I've ever seen in a puzzle. Seen and done a lot SET, but never anything like this before.

Another hard sudoku Mark makes look like a piece of cake! I give up, I will never be as good as you are!😭😭😭

That opening is one of the most amusing SET outcomes I've ever seen... 😂

made a mistake near the start, found out about it one hour down the line, don't have the heart to redo it, i give up the set thing that gives away three initial 0s was clever tho, liked that

I did only use column 3 and 7 for the break-in. Column 3 adds up to 36, swap the circles and arrows where possible, add on the 2 10-sums, and you are left with 2 cells that has to add up to 16. Same trick applies to column 7 with a twist that makes R5C7 a 0.

Today I need to use some hints to solve this. You use set, so I tried and got the 3 zeros. Then you pencilmark 3467 in the first row and I got both 8 in the arrows. And your middle cell helped me too!! Thank you! 😀

Used different sets for break-in (c12 vs box4 and c89 vs box 6). It seems to give you some eights a bit faster, but misses that hilarious 0-value set of 3 cells that Mark found.

I don't like SET puzzles, but hats off to the setter here, he must have been chuffed to have discovered that.

I started with different sets (C1, C2, C8, C9) vs (R1, R9, Box4, Box6). Found the same 0's, without needing to worry about double counted cells.

Finished in 108:07. I really dislike arrow sudokus, mainly, because I'm not good at them. Challenging puzzle.

Crazy break-in‼ 🤣 A cosmic effect obtained with a trifling, minimal twist of a standard ruleset. And beautiful logic does not stop there‼ I bet this beauty will be on volume 3 of *CTC Greatest Hits.* 👏👏👏👏👏👏👏👏👏👏👏 Also, this video contains excellent teaching by Mark. 😏👍👍👍👍👍👍👍

@Paolo_De_Leva

22 күн бұрын

_"What I normally remember quite quickly when I am doing an arrow puzzle..."_ (Mark @7:09) Interesting. It took a while for me to discover the *Phistomefelian* SET trick, and I discovered it by identifying the four symmetrically arranged 2x2 squares containing 3-cell arrows. Initially, I did not notice the position of the circles.

00:57:03 for me. I used set theory in a different way to get the 8's in the circles, but I like Mark's way finding the 0's better :) Kind comment.

First time I've spotted the the corrects sets without playing around with them.

Actually, had you stuck with your very first sets - you could have gotten to the triple-zero break in straight away. It's funny - I got stuck for ideas, watched till you started with the SET - with purple being 2 full sets more than green - then I paused the video, tried those sets - got the 3 zeros (after wondering for a few seconds what had gone wrong, doing it over again very slowly and realising that 3 zeros are the only way that could mathematically work) - then I finished solving, got back to the video to see how you continued and to my surprise I saw you immediately changed the sets! Quite an interesting puzzle - challenges all our semi-automatic assumptions.

Mark's Set Equivalence Theory (SET) trick can be simplified using a simple permutation of *Phistomefel's theorem.* @6:42 Mark showed four symmetrically arranged *2x2* squares containing 3-cell arrows. They are a permuted set of the standard *Phistomefel squares.* The corresponding *permuted ring* can be easily found by comparing two sets: 1) *Purple* = The *4* columns intersecting the *2x2* squares 2) *Green* = The *5* rows that do not intesect the *2x2* squares Remove *box 5* from set 2, then remove the cells shared by the two sets, and you will obtain: 1) *Purple* = *permuted squares* 2) *Green* = *permuted ring* By the way, the *standard ring,* can be found by applying exactly the same technique, with reference to the *standard squares* (the *2x2* squares at the corners of the grid.)

@Paolo_De_Leva

22 күн бұрын

More complex permutations exist, but they are all obtained using the same comparison, except that sometimes you subtract *box 2, 4, 6,* or *8* from the second set, instead of *box 5.* For instance, if the *2x2* squares are in the upper-right corners of boxes *1, 3, 4,* and *6,* you need to subtract *box 8* from the second set.

23:30 for me. Awesome one, really enjoyed it!!

11:52 I think what mark did here up to this point applies to any sudoku. We should call it the mark ring

11:44 Yes, it is exactly a permuted Phistomefel ring! 😄

Very nice puzzle. I tried it for 1 hour but couldnt find a good start. Is there a way without Set-Theory to solve this? Very impressed by the puzzle and its solution.

I finished in 99 minutes. There is no way I was able to get that break-in on my own. What's even worse is that the one deduction I did make was that the arrows in row 1 and 9 had to have a 0, because I thought that it destroyed the X clues by using too many small numbers. Unfortunately, I forgot that 125 avoids all that. So, the one thing I actually did was completely and absurdly wrong. I'm not sure I fully understand SET Theory, so when they show up as the break-in, I tend to get lost. Otherwise. I still enjoyed it. Great Puzzle!

Is there a quick non-set-repl sudoku method to solve this??? First solve hazard a guess both R1/R9 sums contained all nonzero The non guessing way i found 1) prove theres a overlap b/w B3 and B9 sum.(Which goes R5C7) 2) prove the rightside Xsums are diff. (Tho this aint necessary as it comes thru dd) 3) test nonzero sums on each corner box sums to prove the 0 belongs to 3 of them. 4) and then the branching: for 2 boxes test out the 0included sums(5678) to get the Xsums partner. That gives u the R1/R9 sums. And then the soln remains the same

26:13 for me. Nice puzzle!

Started cracking and failed epic by ignore the first rule. I used 1 to 9 instead of 0 to 8. So got I in the last two columns an impossible result.

This was nice!!

So much harder than the time of the video implied

This one tortured me some. Each deduction felt like pulling teeth. I was able to quickly determine that the three X clues on the right side of the grid played off each other in a way that made them have to each be unique, but it took me some time to disprove the location of the 46 pair in two of them through somewhat complicated chains that you could barely hold together in your head. From there the other two fell out pretty quickly with a little easier logic, but then the puzzle dried up again for some time. I knew I needed to look at the lower left where a plethora of clues would work against each other, but even then the chains were long enough I basically considered it somewhat of a bifurcation, though a few proved to disprove quick enough to not feel strained. Then the puzzle finally broke with the V clue in box 4. Still, I'm almost positive I've missed some logical deductions or some math/geometric trick that would have made the solve easier. Time for CtC to school me again. :)

@jdyerjdyer

20 күн бұрын

That was an amazing SET theory opening! Wish I'd spotted it myself. Oh, well. :) Thanks for the painful (yet fun) lesson!

That was really hard work and it took me ages, but nevertheless I enjoyed this great puzzle very much.

Solved in 33:07. I had the same break-in as this video.

Nice

at 22:20, I'm having trouble following what logic is used here. the only thing I can see is that if you don't put the digit in R3C7 in R7C9 or R8C9, you get an unresolvable deadly pattern and the puzzle can't be unique. Because, as I understand it, uniqueness isn't valid logic on its own, I came at this in a more roundabout way, but is there something else here in the logic I'm missing?

I laughed before you did. At first I'm like......wait. Then I realized and started laughing. Then you realized and did as well.

Finished in 26:47 by following along with the video.

When I open this puzzle on the website, the correct ruleset is shown. But when I then load it into the Sudokupad App, the standard classic rules (1-9) are shown. Maybe there is a bug?

22:20 Why can’t r4c7 be in r1c9 or even r9c9? Why does it have to be in r7c9 or r8c9?

@skiesofarcadia4885

23 күн бұрын

Exactly what I'm wondering

@xitvono

23 күн бұрын

It's a mathematical argument. The 2 arrows contain the digit 0 twice, as well as 1, 2, and 5, and one other digit. The sum is 8 + the other digit, so the other digit is in the circle at R4C7

@skiesofarcadia4885

23 күн бұрын

@@xitvono Ah, I see. Thanks for the explanation!

@TheRodOvi

23 күн бұрын

It is because of the totals. R2C9+R3C8+R3C9+R7C9+R8C8+R8C9=R9C7(8)+R4C7 We know 5 of the 6 digits in R2C9, R3C8, R3C9, R7C9, R8C8 and R8C9. The digits are 0, 0, 2, 1 and 5 exactly the total of R9C7=8 So the missing digit must be the total of R4C7. It cant be placed in its own arrow, R8C8 is already occupied by a 0 or 2, so the only alternatives are R7C9 and R8C9. I also had difficulty following that conclusion, so I paused the video to make sense of it. Hope this helps.

@ashutoshsodhani

22 күн бұрын

@@xitvono But the circled digit can also be in R8C8 - which is not yellowed.

Everyone here is, obviously, one of Simon's favourite people. Therefore, they are allowed to now the modified secret: The sum of all the elements in any row, column or box in this puzzle is 36. Once we do the inverted phistomefel ring, we know that R1C4 is a 0. Furthermore, we are given that R1C1 + R1C2 = 10, and R1C8 + R1C9 = 10. So, we know that R1C1 + R1C2 + R1C4 + R1C8 + R1C9 = 10 + 0 + 10 = 20. So, the remaining cells add up to 16. That is, R1C3 + R1C5 + R1C6 + R1C7 = 16. But, we have the arrow for R1C5-7 add up to R2C8. So, R1C3 + R2C8 = 16. But the largest that two cells can add up to is 16, and that only happens if they are both 8's. So, R1C3 = 8 and R2C8 = 8. That's a bit easier than the approach he used to get those.

Isn’t “SET Theory” tautological?!?! 😮

Let's Get Cracking: 02:48 What about this video's Top Tier Simarkisms?! Bobbins: 3x (01:13, 14:12, 14:12) Three In the Corner: 2x (33:59, 34:01) Phistomefel: 1x (11:43) And how about this video's Simarkisms?! Clever: 6x (26:30, 26:33, 38:48, 38:52, 39:03, 39:16) Lovely: 5x (12:32, 12:44, 26:30, 31:30, 38:48) Hang On: 5x (14:02, 14:02, 14:05, 20:41, 21:12) Obviously: 5x (11:36, 11:59, 14:35, 21:47, 24:14) Bother: 4x (27:26, 34:37, 34:37, 34:37) Ah: 4x (15:13, 23:23, 26:30, 37:42) Pencil Mark/mark: 4x (21:34, 32:57, 35:35, 37:55) Sorry: 3x (09:18, 15:43, 25:38) In Fact: 3x (27:08, 30:32, 37:31) Goodness: 1x (38:05) In the Spotlight: 1x (34:01) Stuck: 1x (27:59) Deadly Pattern: 1x (38:17) Gorgeous: 1x (32:04) By Sudoku: 1x (14:26) Shouting: 1x (25:38) Fabulous: 1x (02:33) Lunacy: 1x (04:02) That's Huge: 1x (37:31) Have a Think: 1x (19:58) Uniqueness: 1x (25:53) Weird: 1x (23:23) Most popular number(>9), digit and colour this video: Thirty Seven (10 mentions) One (74 mentions) Green (21 mentions) Antithesis Battles: Even (15) - Odd (3) White (8) - Black (0) Column (19) - 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!

i dont get why you cant use uniqueness as a solution. People keep saying use logic instead. but it is logical to use uniqueness because you know the puzzle has a unique solution. Same logic is used to say there needs to be a digit 1 to 9 in each box row and column. i guess the only exception to that is the uniqueness is more like an unwritten rule. If you know the puzzle has a unique solution. then it is Logical to use uniqueness to help solve the puzzle.

@RichSmith77

23 күн бұрын

Speaking for myself, one of the core aims of solving a puzzle should be to prove that it has a unique solution. For these hand-crafted puzzles, there should always be a logical path that proves it has a unique solution. The reason the puzzle exists, in my view, is to challenge me to try and find that path (or an equivalent). If I rely on uniqueness to fill in the grid, then sure, I have a solution, but I don't feel like I've actually solved it the way the constructor intended. I enjoy the challenge of finding the logic that proves there's one solution. It's the journey, rather than simply reaching the destination, that's fulfilling for me. Also worth remembering that the setter couldn't themselves just assume they had set a puzzle with a unique solution. They, and the early testers, had to prove it was a valid puzzle with only one solution. If it's only possible to do that through brute force using a computer, then it fails as a puzzle, in my view.

27:10 for me

57 minutes

49:34 for me