Outfoxing The Sudoku Trolls!

[@ChrisNeffshade]

ChinStrap here. Thank you so much for the feature. You hit all the major points I think. I want to thank Marty Sears for introducing both these constraints, especially the index lines one as I have set more index line puzzles than anything else. Also for being a great resource and mentor on my settng journey. Only discovered CtC and variant sudoku in January and am glad to be a part of such a wonderful community.

[@d4r4butler74]

Wonderful puzzle!

[@emilywilliams3237]

Congratulations on your channel debut, and what a good puzzle it is! Thanks for creating it and sharing it.

[@ChrisNeffshade]

My Simon debut at least but I actually did have one other feature Simon was just mistaken there kzbin.info/www/bejne/ooileXh6drysmMUsi=SCNsNav7fTttX92v

[@emahalingam1934]

Loved it! Speaking of ChinStraps, I gotta buy my son a new helmet ASAP (for his bike to school).

[@liquidjoe71]

I worked out the following "secrets" of index lines: * A line of length N contains the digits 1-N once each, * A digit on the line either references itself or is in a pair of mutually referencing cells, * An odd length line must contain an odd number of self-referencing cells.

[@juriaanpeet3173]

"If you make a mistake counting your circles, we will be in a world of trouble"... I couldn't agree more after counting 25 circles and staring at the puzzle wondering why it was broken for half an hour.

[@neil2796]

Simon's ability to forget the rules while applying them is impressive.

Thanks for the shout-out, Simon. Took a break from work for a walk and its really not so bad in Montréal today, its 8 right now. I'll give this puzzle a proper watch once the kids are in bed.

[@kennetsdad]

Great puzzle!

[@Kraxxus-vonDalaran]

I do not understand the green logic, why green in box 1 could not be in col 23 in reverse order?

[@warrenbrodsky7409]

As a computer programmer, I can assure you that index puzzles are not always so easy for us, especially since the indexing doesn't start at 0. As the saying goes, there are 2 hard problems in computer science: cache invalidation, naming things, and off-by-1 errors.

[@st3phgr1ce]

Agreed even though I am primarily a BI/Database developer. Unless you are dealing with pointers and such on a regular basis I’m not sure our profession helps. lol I also love how we are all lumped together on non-IT folks’ mind….especially your family who always seem to think you can fix it all!

[@carlosmp2043]

I see what you did there lol

[@andrewgrant6516]

The clock on my kitchen oven goes from 23.59 to 24.00 to 0.01 My heart bleeds at the thought of all that memory wasted on a 25 length array. We went to the moon on less than that!

[@emahalingam1934]

Index Puzzles are in general Better than Middling Puzzles, just like Index Fingers are in general better.

[@brianj959]

😂👏👏

[@jongurney3810]

25:20 Beautiful example of the 'oh you've been shouting at me...' when in fact I've been staring blankly trying to 'see' the last few steps never mind the next one...

[@martinbull-gundersen8878]

I was (silently) shouting just a little, but that was quite probably because I had just solved the puzzle myself and knew he really needed to return to those 8's to get further. I'm very happy no-one watched me and shouted while figuring it out 🙂

[@MorganZex]

A little thing about indexing lines (not often useful, but sometimes it is): the amount of digits indexing themselves must be of the same parity as the line's length. In other words: an even-lenght line can have an even number of digits indexing themselves (if any), and an odd-lenght line MUST have an odd amount of digits indexing themselves. That's due to digits forming pairs indexing each other.

[@moltencucumber6514]

This channel is one of my favourite things to have on while doing homework. I'm currently suffering through calc by hand, and this video has given me the strength to work through it. Thanks for all that you do

[@steave435]

You figured this out way faster than me, but two fairly important things I noticed: 1) You can figure out the digits that go on index lines quite a bit more easily - a N length line simply contains the digits 1 to N. If a 5 length line contained a 6, it would be indexing its position to a position 6 on the line, which is not possible. Combined with "no 9s in circles", that instantly gave a 9 in either r9c7 or r9c8. 2) You could have kept up counting down looking for 9s, 8s, 7s and then 6s etc. Once you concluded that all the other boxes had to have a circled 7, you also knew that all the other boxes except for one had to have a circled 6, which became significant as soon as you placed the 6 in box 9 at 47:00. That could have instantly told you that r6c4 was also a 6, indexing a 5 in r5c4, completing the line with a 7 in r4c4.

[@emilywilliams3237]

I loved this video - I sometimes think that the newest rules get a flurry of activity and then (usually deservedly) die off into oblivion. This Counting Circles idea has staying power, I think, and I'm glad to see that it does. It creates some interesting logic in a puzzle. A nice combination with indexing lines (which I also had some trouble keeping my mind straight about), and of course you delivered a beautiful solve, Simon. Thank you!

[@A_CC_K]

Best way to spend a cold evening watching CtC under a blanket with my dog. This puzzle looks interesting.

[@DjurslandsEfterskole]

An audible "wow" escaped me at 26:00. I had struggled to spot the logic, and clear and simple logic appeared, as out of thin air, when you called attention to it. Thank you so much for guiding and providing insights to these puzzles! I would not have found it on my own ETA: Wonderful puzzle! Very satisfying to solve alongside the video. Felt like learning how to ride a bike - being pushed in the beginning, starting to peddle along until I could finish it off on my own. I had a wonderful time

[@David_K_Booth]

Fully agree - this is a delightful puzzle, and I'm glad that Marty brought it to your attention.

[@jr637-1]

I think for the purposes of future index lines, you can always say that an index line of an odd length will always have at least one digit indexing itself, and you will always have an odd number of digits indexing themselves, up to the total length of the line.

[@janerobson2297]

Simon worked that out in the Finks puzzle but forgot it this time. I think having circles which he is much more comfortable distracted him. He had a (to him) more natural but (to us) a much harder way of thinking about the puzzle. But saying that he did a fantastic job. And it is wonderful to see a genius learning new skills.

[@Paolo_De_Leva]

100% gorgeous‼ I propose we all go to *LMD* and give our honest rating now. Thank you *Simon, Marty Sears* and *CTC community* for redeeming this memorable artwork.

[@Paul-cn3ij]

Really enjoyed that. Felt like some of the logic was outside the norm. Took 44:31. Will enjoy watching Simons' solve later to see if he broke in the same way as I. Again, a really great puzzle ChinStrap.

[@titusadduxas]

1:08:59 - Brilliant. What a lovely debut @Chinstrap. Some gorgeous logic in there. Loved it!

[@Magickal_Gamer]

Simon calling me one of his favorite people always helps with during the bad times

[@kafkapharnaum2690]

What a great gesture (and puzzle of course)! Actually I'd like to use this opportunity to recommend a puzzle by (oft' featured) 99%Sneaky, from his 'Physics' series (using an original ruleset) that suffered the same fate -- and yes, 84% is hardly a bad rating, but with so many great setters nowadays lining up +90 ratings, 84 will definitely get overlooked, and undeservedly so. 99%Sneaky's "Physics 201: Meteorology" on LMD is absolutely great and original in making a very elegant use of a sudoku technique that is often a bit maligned, and at a 3/5 LMD, it's right in the middle between approachable and no walk-in-the-park, The series continues with 301 and 401, but 201 is probably the most CTC-friendly :)

[@chocolateboy300]

I finished in 55:37 minutes. This was an excellent puzzle that beautifully meshed together two cool rulesets. I love the way this was construction that forced some digits to avoid being on the line again and avoiding circles. I think my favorite part was realizing that 7 in r8c1&2 ruled out a 7 from r8c6, which forced a 2 onto the line in row 8. This forced r8c3 to be an 8 and gave a great amount of progress. I very much enjoyed this one. Great Puzzle!

[@ericpraline1302]

This definitely deserves to be highly rated. I find index lines somewhat head-wrecking but once I was able to make some deductions it became a very satisfying solve.

[@amberiscoool]

I can't believe this was uploaded on my birthday and I didn't ask for a shout-out! Guess I'm getting older... Great puzzle and great video! The combination of the circles and index rule was really fun

[@grahamania]

00:36:27 for me. That was a great puzzle. Loved how the lines forced what was in the circles! Kind comment.

[@davidhughes7174]

Thanks again Simon, making the complicated look easy. Well done.

[@leefisher6366]

2:13 - If Alex is only 40, how can he have a secret cake? He needs to wait another 5 years for that!

[@jimbothefuzzy]

I think Simon might need to fix the defroster on his brain before winter really sets in. I don't have any suggestions, and I'm mildly concerned that the best solution will be "Put more sudoku in his sudoku puzzles."

[@emahalingam1934]

winter is coming

[@emanuelneagu14]

Kind reminder that while there are quite a number of geniuses around here, the vast majority of people watching don't even dare to try these puzzles, hence only 20 solves, so I hope you're just being humble and polite with the remarks about your own brain, Simon, because you don't have much of a reason to consider it obtuse or lacking in any capacity.

[@andrewgrant6516]

Classic Dunning Kruger effect. Simon expects everyone else to be as good as him, so he never feels smarter.

[@sgtpepper1790]

It's also important to remember that while the puzzles may have existed in the program for several weeks, most people don't know it even exists until it's featured on this channel. These videos are probably the most exposure these puzzles will get, so, generally, it's logical that play/solve counts will be low before the video is posted (i.e. at the time Simon and Mark are solving and recording them). Are the SudokuPad puzzles even publicly available prior to posting the videos?

[@emanuelneagu14]

@@sgtpepper1790 you're right, now the solve counter is at 1600 after 12 hours, yet it's still 10% of the view count of this video. The puzzles are available before yes but few people see them, and most of those are the geniuses eating these for dinner, which there aren't so many of, and which Simon is one of (that was the point I was making).

[@Dazreil]

I don’t know why but I find index line one of the easiest variant sudoku rules to get my head around

[@imatrot]

Some general logic for indexing lines 1) an N length line contains the numbers 1 to N 2) an odd length line must contain at least 1 self referencing cell or if more, an odd number of self referencing cells 3) an even length line contains eithe 0 or an even number of self referencing cells

[@aliengeo]

You can state the latter two rules more concisely, as 1 is odd and 0 is even: The number of self-referencing cells on the line is the same parity as N, including 0 if N is even.

[@imatrot]

Fair enough

[@FolgoreCZ]

A good general rule for index lines is this: "An index line of length N must only contain digits 1 to N." Not very useful in this puzzle, where it only limits 9 in box 9 to two places, but it could be handy with shorter index lines.

[@chameleon_yura]

Thank you for explaining the rules! I believe that the way they are written in the puzzle might play a huge part in the puzzle being downrated.

[@jeffreyrosas1784]

First, thank you for ignoring the LM trolls. They are a nuisance. Second, I tried this puzzle for a little while and decided to watch you solve it. I had not seen the elimination of candidates you found at 25:40. That was smart. Third, I encourage your viewers who are on LM to take a minute and enter the solution code on the LM site and give this puzzle a nice rating so that puzzlers searching that database for frequently solved or highly rated puzzles will not miss it. It currently shows only 60 solves and 93% even though Sven’s sudokupad shows almost 3500 solves.

[@piarittersporn]

What a brilliant puzzle. Absolutely enjoyable.

[@rowan1230]

A little over two hours for me, but this was one of the most fun puzzles I've ever solved (and I think the hardest I've done yet...)

[@52392daner]

This was a mind bender for me. Your insights were just incredible! One thing I'd like to say is that there is a weird thing about self-referential digits in these things. If the length of the line is odd, there is AT LEAST 1 self-referential digits on the line. If there are more, the quantity of them is always odd. If the length of the line is even, then there could be no self-referential digits or an even number of self referential digits. It's a pain because it creates additional ambiguity where you would much rather have clarity :P

[@GM_Alexandria]

39:00 - Always love Index Lines. I'm glad I pushed them enough in the Discord that they seem to have caught on at least a little!

[@alanclarke4646]

Oh no, they are horrible! I REALLY struggled with this puzzle.

[@martysears]

Great puzzle, really enjoyed watching the solve

[@AcanthaRayneOakMoon]

What a fascinating take on a line. Seemed counter-intuitive to you, Simon, but it's always fun watching you conquer things with that trait.

[@MaritWatery]

The way I think of index lines, they are essentially renban lines that always contain a 1. So the highest digit is the length of the line.

[@emahalingam1934]

Best Possible Explanation!

[@emahalingam1934]

Subsets of and hence Also Renban lines including a 1

[@Dodo2702]

The easy way to think of these index lines is the following: Think of it as a permutation of the sequence of the digits 1 to N, where N is the lenght of the line. You start with that sequence of 1 to N and are only allowed to swap two digits at a time and youre only allowed to swap every digit once. That way you get all the possible variants of an index line. So by starting with 1 2 3 4 5 you can get to 1 3 2 4 5 by swapping 2 and 3. You could then go to 5 3 2 4 1 by swapping 1 and 5. After that no further swapping would be possible.

[@andrewmoore2295]

cant wait for you to do rat run connectedness, its amazing. Now i get to watch and do this challenge aswell

[@dikinebaks]

Index Lines are so fun, reminds me of 159. I hope it gets popular in the future

[@Brandon37_]

As we all know, Simon is very foxy

[@nicocost33]

1.10.22 for me. That was FUN!

[@roccov3614]

OMG, took me days to finish this. Nearly gave up a number of times. Finally had some good sleep and I think I was finally clear headed enough to finish it. It flowed good but was too much effort to work out.

[@janerobson2297]

50:42 let's spend ages talking about 345 circles and ignore the 8 digits in row 7 which would disambiguate the 14 in box 5!

[@Vivo-cp2rb]

It took about 30 minutes to figure out how index lines work and that a number on it either index themselves or pair up with their index. How can you write a number on a line and not immediately look at where it is indexing. I'm baffled

[@steveboltonhill]

I loved this puzzle. I would like to see another solve where the 7 in box 8 was the first digit placed.

[@leefisher6366]

Squell is fine. It's a portmanteau word for 'Square Cell'. It isn't in the dictionary yet, but if Suzy Dent sees this comment, she might be kind enough to add it to the next edition. (Or is that Victoria Coren-Mitchell's work?)

[@katiekawaii]

I have a guess as to why this puzzle was downvoted. It took me a long time and a lot of small moves until I really "got" it, and if I didn't have your assurance that it was a brilliant puzzle, I could see someone not knowing if the problem was them or the puzzle itself, getting frustrated, and quitting. Not a great reason, but that's what I suspect.

[@TheMNbassHunter]

A good troll would note that Simon's indexing line example with 5-1 was incorrect. He put the 1 in the 4th position. 😂

[@atonaltensor]

At 33:30 I’m not following why the line must contained a CIRCLED 7. Couldn’t it contain a non-circled 7?

[@ChrisNeffshade]

Because there are only 2 non circled 7s, one in box 2 and one in box 1 or 4. All other 7s must be circled in order to make the count work.

[@MrGunner44]

yeah i also think simon made a mistake there, he did not rule the chance of 7 being on the lower circle in box 9 and in the upper circle in box 8, and ended up getting digit 8 in box 9 by luck at 38:25 (i restricted that digit to be a 2-8 before getting it was an 8)

[@ChrisNeffshade]

@@MrGunner44 If the 7 was in the lower circle in box 9, the 7 would then have to be off the length 8 line in both box 8 and 9, because the 7 has to be circled in both boxes. But the 7 must be somewhere on that line (otherwise what would you put in position 7 on the line)?

[@MrGunner44]

@@ChrisNeffshade nvm im slow, somehow my brain did not accept the association between "every remaining 7 must be circled" with "the 8-length index must have a 7", dont know how that jumped over me. Biased too because i did not count my remaining circles for 5 6 7 until later on my solving run. It could have saved me 15 minutes or more. Thanks for the puzzle Chris!

[@yadiracamacho499]

00:54:04 for me. Thanks for the puzzle!

[@donmaster8345]

Amazing puzzle! Shame it got hit by trolls, hope it will regain the rating it deserves soon!

[@benjaminwilson9193]

I don't understand the logic to eliminate the 1 out of column 3 row 3 at 48:38? Especially since Simon says through Sudoku, and there aren't any 1s in that column. Edit: noticed the 4/9 looking at the cell. I was focused on the 1s.

[@minamagdy4126]

Wwlcome to What Might Simon Miss, where I state a mid-puzzle deduction, then we see whether Simon finds a more convoluted way of solving the puzzle. Check my reply to see whether he uses it or not. Today on the (inaugural) what might Simon miss (spoilers, obvs): At 24:00, 8 is the other high digit excluded from circles. That is because there are only 7 disjoint "regions" of unique digits that contain circles (those being the boxes 1/4 line, and boxes 3 and 5-9), so no digit can possibly appear in 8 circles without duplicating in one of them (I don't believe they have to be disjoint, but they are).

[@minamagdy4126]

Of course he immedately finds it (at 25:00). Well, we'll see next time.

[@RichSmith77]

I suppose no one could predict that Simon would end up getting the final digit in row 7 (from 47:55 to 51:46) by a more convoluted method. But I look forward to future installments. 🙂

[@srwapo]

54:45, I went from 20 minutes not really knowing how to start (I did a bit of set theory around the line going through box 4), then flew surprisingly fast once I got a foot in the door (digit in the grid?).

[@bethdoughty114]

There are 26 circles, therefore the digits that go ito them must add to 26 and we know that '9' is not one of them. Those were the first two things that I saw. So what makes 26 AND there has to be a total of 26 of them? That was my approach. We both end up with the same numbers in the same places, but I think I got there a bit sooner than you.....not that I timed it, iy just felt that way. 😇

[@johnpauladamovsky86]

ChinStrap is a great Nick-Name...!

[@bobbie0976]

Awesome! Just over half an hour.

[@basil8940]

Count the circles? Now count the squares >D

[@Coyotek4]

30:29 ... solve counter is up to 389 with my solve, and rightfully so; this sudoku deserves more than the troll-bobbleheads give! Nice puzzle!

[@HolySpicoli]

How did we figure that 2 is never circled?

[@walourezo5099]

There are 26 circles so the sum of the circled digits is 26. We know from the line in boxes 1 and 4 that there are at least 6 different circled digits (digits cannot repeat on a line). If there were 7 circled digits their sum would be at least 28, so we now know there are exactly 6 different circled digits. From the secret, we know the 3 non-circled digits sum to 19. 9 is not circled because it can't appear in box 2, and neither can 8 because it only appears once in boxes 1 and 4, on the line. The final missing digit is 19-9-8=2.

[@HolySpicoli]

@@walourezo5099 Thank you. I missed the part where he explains this and after rewatching he does kind of breeze through it. There must be a proof on this but you can recreate it if you start thinking of circles from 1 (1 circle must be 1 circled 1; 2 circles must be 2 circled 2s; 3 circles must be 2+1 or 3, etc.)

[@Roblilley999]

00:29:24 Really pleased with that

[@katrinz.8389]

63:12 took a while and a lot of thinking, but enjoyed very mucg

[@Gonzalo_Garcia_]

14:06 for me. Great puzzle!! Pretty unfair rating on LMD, definitely deserves to be over 90%.

[@LednacekZ]

19:05 for me. horrible solve. i made so many small typos. honestly, i should not have been able to solve it with the amount of mistakes i made.

[@IBoltOnAI]

Hi Simon, how do I get a happy birthday shoutout?

[@TurquoizeGoldscraper]

62:22 for me.

[@jacquespictet5363]

Using sudoku is not cheating. Just saying.

[@Pritchie45]

37 minutes

[@strawberrymilk3695]

I have been waiting to watch before sleeping! Am i the first comment? Haha

[@stuartmcconnachie]

*Please* - Is it somehow possible to reduce the bass line/drumming that permeates all of your videos? It’s particularly annoying when you aren’t speaking.

[@mariuswarin7227]

papa daddy