Simon is the only person who can be really happy with being able to put a three in the corner, and then immediately afterwards use a completely different logic to solve a 38 pair in the same box as the three.
I just love how Simon blatantly ignores a cell that can only be one color cause of the orthogonally connected rule (which would also solve several other cells) and goes on an advanture of what each line represents to figure it out by using the 2x2 rule. That's just priceless.
Give one of these long ones a try some day! You may surprise yourself. Of course, you’ll need to invest more time, but no way to learn other than digging in!
At 36:15, that shape on the left, that Simon pondered whether it was blue or the fourth colour, it could never be blue. Once the two blues were connected, whichever side of the blue bridge you introduced a fourth colour, it would either be isolated from purple or green. Once I made that into my fourth colour region, it was possible to colour the rest of the grid just using the four original colours, rather than introducing a fifth and sixth colour, as Simon did. 🙂 Took me two hours in total, but most of that was on the sudoku, after the regions had been identified. Amazing debut puzzle.
I can't even begin to imagine how to set something like this... this may very well be the most intricately, delicately set puzzle I have ever witnessed.
I thought this was going to be the first Phistomefel puzzle in ages, based on the title. IcyFruit is great on his or her own merits, without the need for a comparison.
Never expect too much from youtube titles.. They are used to create traffic.. And it was a pretty easy title to come up with for them if a review litterally said that sentence. And if the name Phistomefel is enough to generate clicks, I sure hope they will use it again in the future.
@@Paolo_De_LevaIn the sense that it has a phenomenal break-in, a new twist on rules, and a masterfully crafted puzzle all together, well, it's at least Phistomephelish.
@@kr12a2y I see your point but there are so many examples of masterpieces with a twist.. I guess my idea is that not even Phistomefel is always Phistomefelic, but when he is, there is something more that very few others can match or remind me. Everything you wrote plus extreme minimalism, amazing geometry, and full exploration of the coolest possible kinds of interactions between clues.
it's so crazy when a simple idea unravels the whole puzzle and simplifies it to "basic" terms and definitions and solves that have already been covered on the channel. combining the updated checkerboard rule, the updated perimeter rule and the line in the top right cell created magic and i managed to complete the puzzle in 51:00 - but without simon's initial help i wouldn't have done at all cause it's just so scary. and i started with that particular line randomly, i wonder if you could start with another one and make it work like that.
@36:50 At this point, you can already deduce the left "blue" line is the 4th color. It can't be green or purple due to 2x2s. And if it's blue, it has to connect to the right blue, and prevents purple or green from being able to touch the 4th color no matter where you'd place it.
Speaking as someone who has color deficiency, Blue vs. Purple has been challenging for a while and now, Dark Green vs. Red. Each of these pairs just blend in for me, so around halfway when the biggest areas were Dark Green and Red, I got very lost. Maybe there's something within the Sudoku Pad color palette or perhaps programming slightly different hex codes for the various colors to make them more distinct? 🤷♀️ Regardless of that, this was a monstrous solve and what a towering puzzle from IcyFruit. 👏
Accessibility concept in programming: use textures alongside colours to make things distinguishable. This could be done with patterns of dots, squares or diamonds or with slightly darker/lines in the background of coloured cells utilizing horizontal, diagonal or vertical lines.
There should be 3 different palettes in CtC software, you can use 27 colors. It's just Simon refusing to swap between options XD He just sticks with the default option (6 colors + grey + black + white)
Typical how they always mention color deficiency when picking blue and orange in a puzzle, but seem to completely forget about it when there’s three or more colors involved 😊 I think a palette with four or five suitable colors would help a lot for most puzzles.
This was a very fun puzzle. I wasn’t busy today so I took a chance to try a difficult one, and managed up solve it in somewhere over 90 minutes! Lots of false starts for me but well worth the effort!
An hour and 10 minutes into the video and Simon has 1 digit with 20 minutes left to go. The suspense of seeing this puzzle finally crumble apart is palpable 😄
Absolutely amazing idea and execution of it - this ruleset is so up my street, it's ridiculous. All the comments from Simon were spot-on... a world-class piece of work.
Unbelievable how some genius can set up such magnificent logic into a Sudoku grid. As Simon said, not only the region setting is amazing, but the sudoku solving afterwards is one of the best of lines interacting with each other. Take a bow IcyFruit
5 hours 15 minutes. Got the colours right, but had to reset to colored grid once because I lost track of information. Too many deductions in different parts of the puzzle. After soft reset, the puzzle just opened up, since I remembered how to eliminate a lot of possibilities, but now had full control over pencil marks. A marathon to be sure, but a pleasant one.
OMG! That was brilliant. I loved the break in making the groups and lines fall into place, and the first digit break in was gorgeous. It took me way too long to advance from there but once I finally saw the route it fell into place quite easily. A truly remarkable and memorable puzzle by @IcyFruit
Dang! I felt like I could have done the coloring while watching the solve, but I was super impressed at the logic for the digits and how it all flowed together even to the end.
You mean 1:29:24 and 1:29:45 - I clicked on your timestamp and it took me to 1min 28sec. I tried it three times, because I assumed it was something I was doing wrong. Please be kind and remember that some of us are idiots!
27:14 Simon skimmed over something useful - you can prove that r6c5 MUST be the same color as the line under consideration, since if it wasn't the little two cell would be the same color and so would form a 2x2
Impressive solve, I had no idea where to start with this so I just watched. I don't have color blindness but that shade of purple is very close in brightness to the gray of the lines; I wish you had switched to a darker purple or some other color.
It was also not clear for me at that moment, but later at 1:07:55 Simon explains that it is because of that virtual region he mentions several times. That digit (r7c4) has to be somewhere on the virtual region, yet it can not repeat on the grey line. Therefore, it should be in other three digits of the virtual region.
The part of the big Loch Ness Renban excluding C, plus the digits along the bottom of box 8, make up a pseudo-9-cell region, being 9 digits that can't repeat, as Simon showed a bit earlier. That means that whatever C is, because it can't repeat on its own Renban line, has to go somewhere in that pseudo-region, which means it has to be in row 9.
Great puzzle, great solve, I as a colourblind person just got completely lost when he chose purple and blue, as they seem the same to me and suddenly 60% of the grid was the same colour for me. :D
Attention Simon: I'm fairly certain that the Alexa thing is when you say "And that's a..." - I actually caught it in another video the other day as well. Figured I'd pass it along since it came up again.
This was fascinating. I attacked it by lettering lines, starting with the longest which was A. R8C8 had to be a different type (B), and it would have to touch the line in boxes 5/6/8/9, so that line was all B. In box 5, if R6C5 was not B, then R5C4/6/7 would all have to be B, creating a 2x2, so R6C5 is B, and R5C4/6 are not. The short line between boxes 8 & 9 couldn't be B. It could only be a new type if A is not C, and would be restricted to the small area bounded by the existing letters. I proceeded like this, merging letters where they had to be the same. When I got into box 3, it became clear that the bulk of the edges was all the same, and had to be renban. The sudoku was also interesting, with interesting geometrical twists. Quite tricky to get started, but it gradually got easier as it gained traction. @ 55:58 - "Oh bobbins!" - It was a good thought, but your deductions are in the wrong order. The renban in boxes 1/4 must contain 5, which means the 5 on the other renban in box 4, which must have a 5, must be in box R7 in 7 where it sees all of the digits except one on the 7-cell renban (which also needs a 5). Therefore, we can place 5 in R8C4, and now R7C3 cannot go on the 7-cell line, so it can't be 6 or 7. @ 1:23:57 - "that's really weird" - not if you'd asked where 3 goes in R9, like I'd been urging for ages. There's only on place. That gives you a 16 pair on the rest of the line, places 3 & 4 in boxes 8 and 9, resolves the 24 pair in box 7, and the short line between boxes 8 & 9. @ 1:25:53 - "and from all of this we're going to learn..." - Look where your mouse is pointing. Your brain is trying to tell you that cell is a 6.
"Divide the grid into 4 sections of orthogonally-connected cells such that each section shares an edge with every other section..." This calls to mind four-colour mapping. As Simon deduced, it is not possible for all four colours to be on the periphery. But it is possible for three colours to be on the periphery (three colours circling a fourth central colour), and for two colours to be on the periphery (two colours circling two central orthogonally connected colours) and for a single colour to be on the periphery (three colours orthogonally connected to one another in the centre, wrapped by a fourth colour). In this case, Simon quickly deduced the correct number of periphery colours.
If it takes Simon 90 minutes to solve it it will take me 90 lifetimes. I tried and failed to create an example of 4 regions that have no 2X2's of the same region that touch all other regions on an orthogonal edge. Update: Actually after much eliminating of 2X2 (and then isolating a group of coloured cells from its brethren, or else reconnecting a group of coloured cells separated from its brethren and then creating a 2X2) I finally did it an example of it.
This is such an interesting example of how brains and intelligences work in different ways. Assuming you're a puzzle solver of any level, I have no doubt you're gifted with good logic and rational thinking, and you're for sure a better solver than me. In fact, I struggle to solve traditional sudokus with medium difficulty and I have only ever solved one no conventional Sudoku in my life. A real beginner. Yet, it took me 2 minutes to set and example of 4 regions that meet all criteria. It felt like tge easiest task of all. Then finding the right division is a different story, but I think it's because I might have a different type of intelligence which is more imaginative and creative. I noticed the same thing with Simon, I could never beat his logic, but I often find puzzles with unconventional logic easier to manage for me than for him. I think whenever something goes out of his schemes it's hard for him to follow. Indeed, my favourite puzzle solve ever was the SUDOKU RULES CANNOT APPLY😂
I solved this puzzle together with my partner in about 205 minutes! We had great fun coloring the grid, but had to bash our heads against our own inexpert scanning when it came to the sudoku lol
my start was completely different. what i did was traced out some of the borders between regions. any L shape in lines would give you a 2x2 if the "non L" cell was the same color as the L, and so you can draw a lot of borders at the start.
Yes. I know choosing colours is very important to Simon, but I think that if he had drawn in some borders that he had identified early on he would have shaved off 10 minutes from the solve. I'm not complaining but knowing how hard Simon finds it to remember hard won deductions later in the solve and often doubts his pencil marks. Drawing in borders would have saved his brain for new deductions.
@janerobson2297 idk about Simon's brain, but eg for borders are pretty much unnoticeable. I'm a visual thinker and even trying to attempt sth like this without any colouring would be utterly impossible 🫠 So I for one love Simon's colouring tendencies 🎉
@@katarzynazofia i colored too, but having borders lets you know instantly when 2 regions have to be different colors. it also lets you see potential checkerboards more easily too
1:23:16 finish. I made a blunder somewhere in the middle where a 7 on a whisper line led me to place a 2, when it could still have been (and was, in fact) a 1. Lots of facepalming and rewinding involved. Definitely a fun puzzle though!
I like how CtC video titles are not clickbait. I was expecting a comparison with the great Phistomefel a bit daunting, but having played the puzzle and seen how amazingly tight the construction is, with basically both separate part of it being hard as nails, I can seriously see a point for the claim to be substancial. As a side note, I like that his definition of region sum line admitting for it to be in a single box for added challenge.
There are three types of puzzles covered on CtC 1. Puzzles I can do myself. 2. Puzzles I can’t do myself, but can keep track of Simon’s logic as he solves it. 3. Puzzles where I lost track of Simon’s logic 10 minutes ago but am still along for the ride. The number of puzzles that belong in the 1st category have been increasing, but every so often, we get another type 3.
Solved the coloring on my own, but the had to watch until 1:05:19 to finish the puzzle. Kind of embarrassing that I missed that renban in box1 was 12345, but we all have funny mistakes now and then. Brilliant puzzle, unsure if Simon said in the video why it's the new Phistomefel as I didn't watch the rest, but I'm really curious if that means I missed something like a new type of ring or theorem in my solve. Seemed like a fairly normal correlations of rules to me, at least, I don't remember anything of a Phistomephel-like nature. Great puzzle, in any case. I highly recommend this one :)
An excellent video as always. I was just thinking that for puzzles like this, after you've determined the identy of the lines, the line drawing tool could be useful to colour the lines (and delineate the regions) as this may help with the colourblindness side of things.
Cracking puzzle and great solve. My only questions is, was the 2 cell line in the top right corner relevant at all as it didn't seem to meet any criterias?
For a long time I got stuck in the mindset that green had german whisper rules, so in box 5 I placed 5 where should've been. It took quite some time to rectify that error. My time was 02:56:39
During my first attempt I managed to solve the four sections part of the puzzle and determine which lines were what from the four options but screwed up the sudoku part of the puzzle somewhere along the way.
It took me a while to understand this as well. At 54:17 Simon highlights 9 cells in Green across box 7 and 8 and shows that they must all be different and so must include all the digits from 1-9. The "C" in box 7 is on the Renban line, so it must be different to all the other digits on the Renban line, and we know that 6 of the 9 green squares are in the same Renban line, so whatever "C" is must belong in the remaining green squares in box 8.
Well that one was hard, I must say. But I think that I did okay. I got quite a good score With the grid split in four Since i did what you did the whole way. (Fills your socks with candy canes and flies away)
"I don't know if anyone else is like this, but I hate popups!" Oh Simon... given that every browser has built in popup blocker these days, and it was one of the first features added to web browsers back in the day, I'd say you're not alone ;)
The best metaphor for this puzzle I can come up with is Tick, Trick and Truck and Gorp, the fourth brother nobody talks about. I really expected to somehow have equal sized regions. lol
"Philosophy is odious and obscure; Both law and physic are for petty wits; Divinity is basest of the three, Unpleasant, harsh, contemptible, and vile. It be sudoku that hath ravished me.” ― Christopher Marlowe, Dr. Faustus
At 1:01:50, how would it ever be possible for R5C2 to be a five? If you think about it then there could not be a five on the FIVE cell renban that starts in R1C1.
Definitely could not solve this on my own. That being said, could someone please explain why C in box 7 had to be on the bottom row of box 8 and couldn't be in R7C4?
Because the cells he highlights in green at 54:18 are a full set of the digits 1-9, so C must appear somewhere in those green cells. Since it can't repeat on the renban line, it has to go in the bottom row of box 8
This is certainly an impressively hard puzzle; I stared at it for ~5 minutes, got nowhere, and gave up. I tend to prefer puzzles for which there is some starting point I can see, and/or logical solve path I can perceive; those are more "fun" for me, personally. That's not to take anything away from the complexity and challenge of the construction here, though; this is a puzzle which is well beyond my ability, and likely that of most (if not all) non-professional puzzle solvers.
Some puzzles have that requirement, but this one explicitly says *IF* it crosses a 3x3 border then their totals are the same, meaning that it is not a requirement here. That "if" does some heavy lifting :)
Near the end there he placed the 4 in R2C3 and he said it'd get placed there 'by sudoku.' However im not sure what would tell us to place it there and not, say, R2C2? It turns out its the right placement as he solved the puzzle in the end with that placement, but i could see the Sudoku logic that indicated its placement.
I know Simon is unlikely to read this... but: what the heck is going on with so many keypresses? At 1:23:46 for example? Just press shift + the number you want to remove! And pressing Z/X/C/V gives you the different modes between big/corner/middle pencilmarks and colors. I legit have no idea what is taking something like 6 button presses in a row. Sorry, this bothers me way more than it should, love you Simon & ctc🥲
Love how Simon always goes to defend how interesting he is to his viewers who all happily take 90 minutes of their day to watch him solve a sudoku
Exactly
Simon is the only person who can be really happy with being able to put a three in the corner, and then immediately afterwards use a completely different logic to solve a 38 pair in the same box as the three.
1:29:49
doing Sudoku in a Sudoku puzzle? Couldn't be me.
I like how CTC is a channel where Simon, Mark and Alexa try to solve puzzles.
But poor Alexa barely gets a sentence in most days. They just talk all over her.
I always love it when, 45 minutes in, you manage to prove that blue is red
Simon: you'll all be so bored if this video is too long
All of us: we'll literally watch a 5 hour solve don't worry
I just love how Simon blatantly ignores a cell that can only be one color cause of the orthogonally connected rule (which would also solve several other cells) and goes on an advanture of what each line represents to figure it out by using the 2x2 rule. That's just priceless.
I love watching a master at work. I try GAS puzzles and things with 30 min videos, but this is beyond me so far. Well done to Simon and the setter!
Give one of these long ones a try some day! You may surprise yourself. Of course, you’ll need to invest more time, but no way to learn other than digging in!
What Zach said. This took me 6.5 hours but was worth every minute.
"This is brilliant!! Oh no, I'm wrong!"
No Simon, you are not wrong. This IS brilliant.
At 36:15, that shape on the left, that Simon pondered whether it was blue or the fourth colour, it could never be blue. Once the two blues were connected, whichever side of the blue bridge you introduced a fourth colour, it would either be isolated from purple or green.
Once I made that into my fourth colour region, it was possible to colour the rest of the grid just using the four original colours, rather than introducing a fifth and sixth colour, as Simon did. 🙂
Took me two hours in total, but most of that was on the sudoku, after the regions had been identified.
Amazing debut puzzle.
Somewhat surprising that something little like Simons happiness about a 3 in the corner always puts a smile on my face 🙂
I can't even begin to imagine how to set something like this... this may very well be the most intricately, delicately set puzzle I have ever witnessed.
I thought this was going to be the first Phistomefel puzzle in ages, based on the title.
IcyFruit is great on his or her own merits, without the need for a comparison.
Never expect too much from youtube titles.. They are used to create traffic.. And it was a pretty easy title to come up with for them if a review litterally said that sentence.
And if the name Phistomefel is enough to generate clicks, I sure hope they will use it again in the future.
Also, this puzzle does not remind me Phistomefel's style at all.
@@Brazz27This, and this title doesnt suggest that the puzzle is made by Phistomefel at all, at best only similar
@@Paolo_De_LevaIn the sense that it has a phenomenal break-in, a new twist on rules, and a masterfully crafted puzzle all together, well, it's at least Phistomephelish.
@@kr12a2y I see your point but there are so many examples of masterpieces with a twist..
I guess my idea is that not even Phistomefel is always Phistomefelic, but when he is, there is something more that very few others can match or remind me. Everything you wrote plus extreme minimalism, amazing geometry, and full exploration of the coolest possible kinds of interactions between clues.
it's so crazy when a simple idea unravels the whole puzzle and simplifies it to "basic" terms and definitions and solves that have already been covered on the channel. combining the updated checkerboard rule, the updated perimeter rule and the line in the top right cell created magic and i managed to complete the puzzle in 51:00 - but without simon's initial help i wouldn't have done at all cause it's just so scary. and i started with that particular line randomly, i wonder if you could start with another one and make it work like that.
@36:50 At this point, you can already deduce the left "blue" line is the 4th color. It can't be green or purple due to 2x2s. And if it's blue, it has to connect to the right blue, and prevents purple or green from being able to touch the 4th color no matter where you'd place it.
Speaking as someone who has color deficiency, Blue vs. Purple has been challenging for a while and now, Dark Green vs. Red. Each of these pairs just blend in for me, so around halfway when the biggest areas were Dark Green and Red, I got very lost. Maybe there's something within the Sudoku Pad color palette or perhaps programming slightly different hex codes for the various colors to make them more distinct? 🤷♀️
Regardless of that, this was a monstrous solve and what a towering puzzle from IcyFruit. 👏
Each solver can set their own custom colour palette in SudokuPad, and I think this is a custom palette that Simon has setup.
Accessibility concept in programming: use textures alongside colours to make things distinguishable. This could be done with patterns of dots, squares or diamonds or with slightly darker/lines in the background of coloured cells utilizing horizontal, diagonal or vertical lines.
There should be 3 different palettes in CtC software, you can use 27 colors.
It's just Simon refusing to swap between options XD He just sticks with the default option (6 colors + grey + black + white)
Maybe the colours could also have different patterns.
Typical how they always mention color deficiency when picking blue and orange in a puzzle, but seem to completely forget about it when there’s three or more colors involved 😊 I think a palette with four or five suitable colors would help a lot for most puzzles.
Rules: 07:06
Let's Get Cracking: 11:59
Simon's time: 1h19m37s
Puzzle Solved: 1:31:36
What about this video's Top Tier Simarkisms?!
Bobbins: 3x (46:25, 55:54, 1:12:46)
The Secret: 3x (15:31, 15:40, 20:26)
Three In the Corner: 1x (1:29:23)
Phistomefel: 1x (00:33)
You Rotten Thing: 1x (49:18)
And how about this video's Simarkisms?!
Ah: 22x (13:50, 16:26, 24:49, 29:33, 39:40, 39:40, 40:44, 48:42, 50:43, 51:45, 51:45, 53:26, 58:17, 1:04:08, 1:07:25, 1:11:38, 1:13:33, 1:15:05, 1:18:36, 1:19:07, 1:20:30, 1:27:31)
Hang On: 21x (15:37, 16:01, 29:51, 29:51, 29:51, 43:18, 48:11, 49:20, 51:47, 53:26, 58:17, 1:02:52, 1:06:12, 1:10:31, 1:11:21, 1:14:22, 1:17:17, 1:18:52, 1:22:41, 1:26:46)
Brilliant: 11x (01:12, 02:04, 03:48, 06:54, 41:05, 45:07, 1:15:27, 1:31:52, 1:31:55, 1:32:21, 1:32:25)
Pencil Mark/mark: 10x (18:53, 19:22, 52:49, 53:13, 57:47, 1:05:26, 1:16:34, 1:26:13, 1:27:36, 1:29:08)
Sorry: 9x (05:52, 19:46, 25:15, 32:24, 53:57, 56:18, 1:00:12, 1:09:22, 1:21:49)
Checkerboard: 7x (20:48, 21:29, 22:27, 23:19, 26:22, 36:41, 38:13)
In Fact: 7x (17:57, 21:19, 28:56, 31:40, 38:18, 1:23:35, 1:26:41)
Gorgeous: 6x (1:05:01, 1:05:01, 1:24:56, 1:28:27, 1:28:27, 1:29:31)
Obviously: 6x (12:29, 17:23, 23:07, 30:57, 33:28, 36:31)
Goodness: 5x (08:24, 26:15, 1:15:23, 1:15:23, 1:24:53)
Clever: 5x (33:03, 33:07, 40:55, 50:46, 50:46)
Incredible: 4x (00:18, 00:53, 45:09, 1:26:32)
Nature: 4x (16:43, 17:51, 1:06:20, 1:06:31)
Beautiful: 3x (06:25, 31:24, 31:24)
By Sudoku: 3x (1:18:57, 1:27:34, 1:29:39)
Shouting: 3x (02:00, 04:36, 06:04)
What Does This Mean?: 3x (43:10, 1:06:55, 1:10:08)
That's Huge: 3x (34:21, 1:08:56, 1:14:25)
Cake!: 3x (06:25, 06:45, 06:51)
Weird: 3x (1:22:41, 1:23:54, 1:23:58)
Useless: 2x (1:00:12, 1:26:43)
I Have no Clue: 2x (20:37, 23:39)
Lovely: 2x (06:17, 1:04:08)
Fascinating: 2x (01:18, 1:32:29)
Ridiculous: 2x (1:05:30, 1:13:33)
Have a Think: 2x (13:29, 30:16)
What on Earth: 1x (35:19)
The Answer is: 1x (59:18)
In the Spotlight: 1x (1:29:26)
Touch Itself: 1x (30:59)
Going Mad: 1x (26:41)
Come on Simon: 1x (1:25:54)
Of All Things: 1x (1:13:28)
Magnificent: 1x (1:31:42)
Surely: 1x (1:29:39)
Unbelievable: 1x (00:36)
Whoopsie: 1x (1:23:39)
Alexa: 1x (1:20:13)
Wow: 1x (33:07)
Triangular Number: 1x (13:57)
Most popular number(>9), digit and colour this video:
Twelve (4 mentions)
One (143 mentions)
Green (95 mentions)
Antithesis Battles:
Low (15) - High (6)
Even (14) - Odd (2)
Lower (3) - Higher (2)
Outside (2) - Inside (0)
Column (20) - Row (8)
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 am continually stunned by the beauty of a puzzle and solve. Thank you Simon and IcyFruit.
This was a very fun puzzle. I wasn’t busy today so I took a chance to try a difficult one, and managed up solve it in somewhere over 90 minutes! Lots of false starts for me but well worth the effort!
Wonderful from you IcyFruit! Fascinating how you were able to constrct this! Great solve Simon with your explicit logical deductions throughout!
Yikes! This looks daunting. I think I shall make some fancy popcorn and prepare for this 90 minute treasure!
An hour and 10 minutes into the video and Simon has 1 digit with 20 minutes left to go. The suspense of seeing this puzzle finally crumble apart is palpable 😄
Absolutely amazing idea and execution of it - this ruleset is so up my street, it's ridiculous. All the comments from Simon were spot-on... a world-class piece of work.
Unbelievable how some genius can set up such magnificent logic into a Sudoku grid. As Simon said, not only the region setting is amazing, but the sudoku solving afterwards is one of the best of lines interacting with each other. Take a bow IcyFruit
This is hands down the most astonishing puzzle I've ever seen! Hats off for IcyFruit what a genius
5 hours 15 minutes. Got the colours right, but had to reset to colored grid once because I lost track of information. Too many deductions in different parts of the puzzle. After soft reset, the puzzle just opened up, since I remembered how to eliminate a lot of possibilities, but now had full control over pencil marks. A marathon to be sure, but a pleasant one.
OMG! That was brilliant. I loved the break in making the groups and lines fall into place, and the first digit break in was gorgeous. It took me way too long to advance from there but once I finally saw the route it fell into place quite easily. A truly remarkable and memorable puzzle by @IcyFruit
Dang! I felt like I could have done the coloring while watching the solve, but I was super impressed at the logic for the digits and how it all flowed together even to the end.
A good colour combination would have been green, yellow, orange and blue.
I personally have trouble telling blue and purple apart myself.
I'm feeling so proud that i did it in 82 minutes, in a few sittings whilst going about my day. Practice is paying off...
1:28 R1C1 'That's 3 in the corner ' 1:29 R2C2 'if that's 3...' Oh Simon we love you.
You mean 1:29:24 and 1:29:45 - I clicked on your timestamp and it took me to 1min 28sec. I tried it three times, because I assumed it was something I was doing wrong. Please be kind and remember that some of us are idiots!
27:14 Simon skimmed over something useful - you can prove that r6c5 MUST be the same color as the line under consideration, since if it wasn't the little two cell would be the same color and so would form a 2x2
Impressive solve, I had no idea where to start with this so I just watched.
I don't have color blindness but that shade of purple is very close in brightness to the gray of the lines; I wish you had switched to a darker purple or some other color.
Supposedly the creator of the popup greatly regrets it. Take what little solace there is to be gained in that...
Can someone explain why at 55:00 C couldnt also be r7c4?
It was also not clear for me at that moment, but later at 1:07:55 Simon explains that it is because of that virtual region he mentions several times. That digit (r7c4) has to be somewhere on the virtual region, yet it can not repeat on the grey line. Therefore, it should be in other three digits of the virtual region.
54:40 - They are 9 different digits, 1 of which is C
The part of the big Loch Ness Renban excluding C, plus the digits along the bottom of box 8, make up a pseudo-9-cell region, being 9 digits that can't repeat, as Simon showed a bit earlier. That means that whatever C is, because it can't repeat on its own Renban line, has to go somewhere in that pseudo-region, which means it has to be in row 9.
Ahh that makes sense, thanks all, noob trying to follow along 😀
53:56 for me. Took me 3 sessions to beat, because my pc crashed twice with severe glitches that made it unplayable.
Great puzzle, great solve, I as a colourblind person just got completely lost when he chose purple and blue, as they seem the same to me and suddenly 60% of the grid was the same colour for me. :D
Attention Simon: I'm fairly certain that the Alexa thing is when you say "And that's a..." - I actually caught it in another video the other day as well. Figured I'd pass it along since it came up again.
The kind of puzzle that make you feel a sense of accomplishment and pride, from beak in to finish..
29:37
Two puzzles for the price of one and both simply brilliant.
Solved this a few days ago - it is brilliant.
This was fascinating. I attacked it by lettering lines, starting with the longest which was A. R8C8 had to be a different type (B), and it would have to touch the line in boxes 5/6/8/9, so that line was all B. In box 5, if R6C5 was not B, then R5C4/6/7 would all have to be B, creating a 2x2, so R6C5 is B, and R5C4/6 are not. The short line between boxes 8 & 9 couldn't be B. It could only be a new type if A is not C, and would be restricted to the small area bounded by the existing letters. I proceeded like this, merging letters where they had to be the same. When I got into box 3, it became clear that the bulk of the edges was all the same, and had to be renban. The sudoku was also interesting, with interesting geometrical twists. Quite tricky to get started, but it gradually got easier as it gained traction.
@ 55:58 - "Oh bobbins!" - It was a good thought, but your deductions are in the wrong order. The renban in boxes 1/4 must contain 5, which means the 5 on the other renban in box 4, which must have a 5, must be in box R7 in 7 where it sees all of the digits except one on the 7-cell renban (which also needs a 5). Therefore, we can place 5 in R8C4, and now R7C3 cannot go on the 7-cell line, so it can't be 6 or 7.
@ 1:23:57 - "that's really weird" - not if you'd asked where 3 goes in R9, like I'd been urging for ages. There's only on place. That gives you a 16 pair on the rest of the line, places 3 & 4 in boxes 8 and 9, resolves the 24 pair in box 7, and the short line between boxes 8 & 9.
@ 1:25:53 - "and from all of this we're going to learn..." - Look where your mouse is pointing. Your brain is trying to tell you that cell is a 6.
"Divide the grid into 4 sections of orthogonally-connected cells such that each section shares an edge with every other section..." This calls to mind four-colour mapping. As Simon deduced, it is not possible for all four colours to be on the periphery. But it is possible for three colours to be on the periphery (three colours circling a fourth central colour), and for two colours to be on the periphery (two colours circling two central orthogonally connected colours) and for a single colour to be on the periphery (three colours orthogonally connected to one another in the centre, wrapped by a fourth colour). In this case, Simon quickly deduced the correct number of periphery colours.
I also thought immediately of the 4 map colors
1 hour in .... "so now we get to start the sudoku"... definitely a new phistomafel
If it takes Simon 90 minutes to solve it it will take me 90 lifetimes. I tried and failed to create an example of 4 regions that have no 2X2's of the same region that touch all other regions on an orthogonal edge. Update: Actually after much eliminating of 2X2 (and then isolating a group of coloured cells from its brethren, or else reconnecting a group of coloured cells separated from its brethren and then creating a 2X2) I finally did it an example of it.
😄 so true
This is such an interesting example of how brains and intelligences work in different ways. Assuming you're a puzzle solver of any level, I have no doubt you're gifted with good logic and rational thinking, and you're for sure a better solver than me. In fact, I struggle to solve traditional sudokus with medium difficulty and I have only ever solved one no conventional Sudoku in my life. A real beginner. Yet, it took me 2 minutes to set and example of 4 regions that meet all criteria. It felt like tge easiest task of all. Then finding the right division is a different story, but I think it's because I might have a different type of intelligence which is more imaginative and creative. I noticed the same thing with Simon, I could never beat his logic, but I often find puzzles with unconventional logic easier to manage for me than for him. I think whenever something goes out of his schemes it's hard for him to follow. Indeed, my favourite puzzle solve ever was the SUDOKU RULES CANNOT APPLY😂
New song for Simon (to the tune of Billy Joels' - the Longest Time):
Whoa-oh-oh-oh, where's the longest line?
I solved this puzzle together with my partner in about 205 minutes! We had great fun coloring the grid, but had to bash our heads against our own inexpert scanning when it came to the sudoku lol
my start was completely different. what i did was traced out some of the borders between regions. any L shape in lines would give you a 2x2 if the "non L" cell was the same color as the L, and so you can draw a lot of borders at the start.
Yes. I know choosing colours is very important to Simon, but I think that if he had drawn in some borders that he had identified early on he would have shaved off 10 minutes from the solve. I'm not complaining but knowing how hard Simon finds it to remember hard won deductions later in the solve and often doubts his pencil marks. Drawing in borders would have saved his brain for new deductions.
@janerobson2297 idk about Simon's brain, but eg for borders are pretty much unnoticeable. I'm a visual thinker and even trying to attempt sth like this without any colouring would be utterly impossible 🫠 So I for one love Simon's colouring tendencies 🎉
@@janerobson2297also, on a bit different note. O think that such a wide and diverse audience it is simply impossible to cater to everyone 😢
@@katarzynazofia i colored too, but having borders lets you know instantly when 2 regions have to be different colors. it also lets you see potential checkerboards more easily too
1:23:16 finish. I made a blunder somewhere in the middle where a 7 on a whisper line led me to place a 2, when it could still have been (and was, in fact) a 1. Lots of facepalming and rewinding involved. Definitely a fun puzzle though!
This one took me several hours. Hard, but beatable! I especially loved figuring out the colors, though I took a very different route than Simon did.
I like how CtC video titles are not clickbait. I was expecting a comparison with the great Phistomefel a bit daunting, but having played the puzzle and seen how amazingly tight the construction is, with basically both separate part of it being hard as nails, I can seriously see a point for the claim to be substancial.
As a side note, I like that his definition of region sum line admitting for it to be in a single box for added challenge.
most enjoyable long video in a while!
There are three types of puzzles covered on CtC
1. Puzzles I can do myself.
2. Puzzles I can’t do myself, but can keep track of Simon’s logic as he solves it.
3. Puzzles where I lost track of Simon’s logic 10 minutes ago but am still along for the ride.
The number of puzzles that belong in the 1st category have been increasing, but every so often, we get another type 3.
An outrageously amazing puzzle! Definitely a "watcher" for me, but so much fun!!!
1:20:06 Alexa = "and That's that digit"
Awesome puzzle!
So, i carefully coloured in the whole grid (the timer is on 27 minutes) and realize none of my regions can hold a palindrome line. 😞
Solved the coloring on my own, but the had to watch until 1:05:19 to finish the puzzle. Kind of embarrassing that I missed that renban in box1 was 12345, but we all have funny mistakes now and then. Brilliant puzzle, unsure if Simon said in the video why it's the new Phistomefel as I didn't watch the rest, but I'm really curious if that means I missed something like a new type of ring or theorem in my solve. Seemed like a fairly normal correlations of rules to me, at least, I don't remember anything of a Phistomephel-like nature. Great puzzle, in any case. I highly recommend this one :)
An excellent video as always. I was just thinking that for puzzles like this, after you've determined the identy of the lines, the line drawing tool could be useful to colour the lines (and delineate the regions) as this may help with the colourblindness side of things.
The complex logic kept throwing me for the easy stuff ..... Excellent puzzle and well worth a try.
* * * * *
That was tricky! Took me 85 minutes but I really enjoyed it. Thanks for sharing it.
Took me 83:10 and I'm thrilled with that time. Absolutely incredible puzzle from start to finish!
Cracking puzzle and great solve. My only questions is, was the 2 cell line in the top right corner relevant at all as it didn't seem to meet any criterias?
I'd say yes, because it forced its two cells to be the same colour. I know it's not much, but it's definitely not nothing.
For a long time I got stuck in the mindset that green had german whisper rules, so in box 5 I placed 5 where should've been. It took quite some time to rectify that error.
My time was 02:56:39
During my first attempt I managed to solve the four sections part of the puzzle and determine which lines were what from the four options but screwed up the sudoku part of the puzzle somewhere along the way.
A bit of the 4 colour map theorem there?
I'm 110% sure Alexa is reacting to "six pair"
At 55:02, why couldn’t C be in the top left cell of box 8?
It took me a while to understand this as well. At 54:17 Simon highlights 9 cells in Green across box 7 and 8 and shows that they must all be different and so must include all the digits from 1-9. The "C" in box 7 is on the Renban line, so it must be different to all the other digits on the Renban line, and we know that 6 of the 9 green squares are in the same Renban line, so whatever "C" is must belong in the remaining green squares in box 8.
Took me three goes just to colour the grid, and then the puzzle got *harder*. Good lord.
Super cool puzzle, nice one IceFruit :)
Well that one was hard, I must say.
But I think that I did okay.
I got quite a good score
With the grid split in four
Since i did what you did the whole way.
(Fills your socks with candy canes and flies away)
"I don't know if anyone else is like this, but I hate popups!"
Oh Simon... given that every browser has built in popup blocker these days, and it was one of the first features added to web browsers back in the day, I'd say you're not alone ;)
I love sudoku you are unbelievable
Why cant initial green (later purple) line on column 9 be German Whispers at 51:00 mark?
It was assumed that it was Renban at that stage
How extraordinary and incredible.
The best metaphor for this puzzle I can come up with is Tick, Trick and Truck and Gorp, the fourth brother nobody talks about. I really expected to somehow have equal sized regions. lol
35:46 for me. Fantastic puzzle, probably the best one I've solved in a while.
"Philosophy is odious and obscure;
Both law and physic are for petty wits;
Divinity is basest of the three,
Unpleasant, harsh, contemptible, and vile.
It be sudoku that hath ravished me.”
― Christopher Marlowe, Dr. Faustus
How does, at 1:03:10, he know that green digit is not in middle row, column 2 or 3 in box 8?
Wow! So fun to solve.
1:01:45 does that mean you can cross out 2 blue 5s?
wow! what a puzzle!
At 1:01:50, how would it ever be possible for R5C2 to be a five? If you think about it then there could not be a five on the FIVE cell renban that starts in R1C1.
Definitely could not solve this on my own. That being said, could someone please explain why C in box 7 had to be on the bottom row of box 8 and couldn't be in R7C4?
Because the cells he highlights in green at 54:18 are a full set of the digits 1-9, so C must appear somewhere in those green cells. Since it can't repeat on the renban line, it has to go in the bottom row of box 8
@@benseavello355 doi thanks!
This is certainly an impressively hard puzzle; I stared at it for ~5 minutes, got nowhere, and gave up. I tend to prefer puzzles for which there is some starting point I can see, and/or logical solve path I can perceive; those are more "fun" for me, personally. That's not to take anything away from the complexity and challenge of the construction here, though; this is a puzzle which is well beyond my ability, and likely that of most (if not all) non-professional puzzle solvers.
I am extremely proud I was able to identify regions in less time than Simon!!
The numbers, on the contrary... 😅
Great puzzle and great solve!!!
This is the hardest thing I’ve ever seen. I’ve been at it for 4 hours and I couldn’t do it.
This puzzle is ridiculous indeed, one of my all-time favorites.
1:23:50 Less weird way to do that is realizing 3 in the bottom row has only one place to go, since you find the "34" pair in box 9.
Yellow and like green, and light purple and light blue, are super close to the same colors
at around 54:00 why can't c be in r7c4
What’s with the 97 in the Region sum - box 3?? It doesn’t sum by why does it have a LINE?
My birthday is today ( I'm watching this video the day after it was posted) and I'm going to decorate my cake to look like a sudoku board!
Do region sum lines have to cross at least two boxes?
Some puzzles have that requirement, but this one explicitly says *IF* it crosses a 3x3 border then their totals are the same, meaning that it is not a requirement here. That "if" does some heavy lifting :)
when red becomes yellow, it doesnt turn yellow, but yellow turns red. the chuck norris of colors. :D
Intuition said one long section and one very small one...that the long one was the outer border...proving it proved quite hard tho
Near the end there he placed the 4 in R2C3 and he said it'd get placed there 'by sudoku.'
However im not sure what would tell us to place it there and not, say, R2C2?
It turns out its the right placement as he solved the puzzle in the end with that placement, but i could see the Sudoku logic that indicated its placement.
R2 only had 348 available, and C3 already had a 3 and an 8.
I think I need to go buy more popcorn - and look up Anthony Etherin…
I really wish Simon trusted his pencilmarks.
I know Simon is unlikely to read this... but: what the heck is going on with so many keypresses? At 1:23:46 for example? Just press shift + the number you want to remove! And pressing Z/X/C/V gives you the different modes between big/corner/middle pencilmarks and colors. I legit have no idea what is taking something like 6 button presses in a row.
Sorry, this bothers me way more than it should, love you Simon & ctc🥲
Q. When C is placed in Box 7, and in Row 9 in Box 8, why can't it be in cell 1 in Box 8?