Me: Needs at minimum 2-3 times as much time to solve it Simon: Please try the puzzle for youself Also Simon: Makes a Video over an hour long and says only one of the testers could solve it at all...
I just got done trying to solve it on stream... Took me an hour to realize the 5 in the middle of the grid! Spent a solid 3 hours before I gave up with about 6 digits in the grid...
Simon: *has an epiphany which requires thinking 8 steps ahead in the 4th dimension taking into account every arithmetic rule known to man kind* Puzzle: *gives one number in return*
Hey, at least it's a digit! in a video I watched recently (everything wrogn the 2nd or so), most of the time 3 mins of thinking gave 1-3 pencil markings :)
5:44 "Straight off the bat, we are up and running" 6:18 "Now that, of course, is completely useless...bother" 6:30 "So where shall we look..." 7:34 "also not very helpful..." 10:18 "Sorry, I am going to stare at this a little bit longer..." 11:01 "Ah, now, now, I have been thinking about his incorrectly... Here is some logic..." 11:08 "Ah, that is fascinating" 12:47 ****NEW PHRASE ALERT**** "This is all stripey" 13:50 ****NEW PHRASE ALERT**** "I have got a very appetizing looking grid" 14:52 "Ah, now, now I have, ah, yes yes, yes" 14:58 "This is lovely geometry" 18:11 "Right, now what on earth am I meant to do with this" 23:16 "Is that in any way helpful.... ah it might be a little bit helpful" 28:25 "Its 28 minutes in and I've got one digit in the grid" 28:35 "Oh Good Grief" 30:10 "I think I am going mad!" 31:48 "What does this mean? I have no idea......Oh, no, I've got an idea, look..." 33:16 "Oh my goodness me. OH MY GOODNESS ME!... Watch This, WATCH THIS!" 33:34 "That is absolutely lovely!" 36:16 "Oh, now, hang on, I've just spotted something else..." 38:29 "Ah Yeah, This is it, this is it!" 40:12 "I don't know what I am meant to appreciate from that!" 42:32 "This is one of the most beautiful executions I can remember, and I am still miles away from finishing it" 46:55 "What a puzzle this is. Every single digit, its' like, you have to come up with, a like, whoa moment" 47:28 "I don't have a clue what I am meant to do now" 57:00 "my goodness me, what a puzzle this is!" 58:17 "So now what do we do? What Do we do NOW? 58:24 "I haven't go a scooby-doo!" 1:02:32 "This is driving me mad" 1:03:03 "And now I can't see the woods through the trees at all" 1:06:37 "I feel like I am being punched in the face repeatedly by this puzzle" 1:08:19 "Oh, is that right? Have we got a naked single?" 1:09:15 "Yes yes YES! This, THIS is the square" 1:10:33 "This might be the best solve I have ever done on this channel!" 1:10:56 "Wow, Wow, that is one of the greatest sudoku puzzles, one of the greatest puzzles I have ever had the privileged to try!"
The bingo card is missing "I have absolutely no idea where to start this puzzle, although wait, if you look here..." (with no pause between the two thoughts of course)
5:44 "Straight off the bat, we are up and running" Almost 30 minutes of intense work later ... 34:35 Gets second digit Also Simon: "do try it out" Me: "Nope"
I love CTC because of how relaxing it is to watch. 38:10 THERE'S A 9 ABOVE IT SIMON, SEE THE DAMN PATTERN! 38:45 He sees a completely off-the-wall impossible piece of logic that resolves the same way and I throw my laptop across the room.
He does the same in two or three other places: I can see it and he takes 5 or more minutes and absolutely ridiculous logic to get the same result. Typical Simon.
@@timowilms8102 Kudos to you for not giving up. I didn't even try this because I've learnt that if a CTC video lasts more than 30 minutes it means that there's no way in hell I'm ever solving that.
Thank you Simon for teaching us how to be patient (1:11:42), how to trust that there must be a way out and that all that we need to do is enjoy the beauty in the problems we face (THAT IS ABSOLUTELY BEAUTIFUL!), and to appreciate this beauty every step in the way. Guys, regardless of the level of difficulty, Simon is showing us that every one of us can enjoy Sudoku, or any puzzle for that matter, if we take the time to appreciate that clicking moment when we figure something out every step of the way. The point is not to solve a difficult puzzle and get to the end of it. That would be ridiculous, I didn't just watch over an hour of video just to know if you will solve it or not, I watched the whole process. The point of life is not what you achieve/obtain in the end.. it is trusting the process and enjoying every challenge on the way. Heck, I bet more than half the people here are not even following the logic, Simon. They are just in it for the sheer joy that you emanate for every little pencil-mark you figure out.
I don't think I could've put it better myself. You're a brilliant combo guys. never give up what you do, and continue to show us the beauty of the journey. The destination (the solution) may be what you're ultimately aiming for, but it's the journey (how you solved it) that is really enjoyed.
Also, most people just want to be left alone with a sudoku, and it's something "useless", and you guys are making it a social thing, and something beautiful .
exactly. I had just finished my daily errands and then sat down in my comfy chair with the intention of solving the new puzzle that I knew would come in at any moment. Saw the clip's thumbnail showing 1h 11m and grabbed the popcorn and let this guy solving it instead of me. As much admiration I have for such brilliant constructors as quickly I nope away from them when I see the pros taking 70 minutes to solve the said puzzle(s) xD
Yeah I try the ones that take them 20 minutes and it usually takes me 2-4 hours and I'm pretty proud of myself. no way am I trying one that took him a full hour
It's certainly too hard for me (as are many), but I often pause his videos to study for a few minutes to see if I can see any next step(s). Mostly, I don't, but sometimes I do. (And, sometimes I wrongly think I have!) It doesn't have to be all or none.
I spotted this, im not sure he did as he kept applying logic to re-solve the partners, if he had it might have shaved 10 minutes off the solve time :D i was ofc still a total passenger
Watching this was amazing, like watching an Olympic event. You lost me fairly early on with the 5’s, but I stayed on. Several times you couldn’t see the forest for the “wood”, so my husband asked me who I was yelling at. When you finally cracked the puzzle, I thought you might faint on the floor. Thanks for taking us along on this journey - I just can’t get enough.
Let's see if I can help you with the 5s. The key is consistently applying the "even distribution" rule: you cannot re-use a digit unless you have used all other digits and successively you cannot use a digit a third time unless you have used all other digits twice. Thus a cage that has 12 cells contains 6 unique digits and 3 repeated digits. The additional consequence from this is that the 6 cells from the 14 cell "snake" that are inside the top right and centre right boxes must contain the non repeated digits from the 53-cage. The digits that **are** repeated in the 53-cage thus must be somewhere else on the 68-snake to complete the full 1-9 range, with one the positions known to be r7c8. The remaining two(!) digits can only go in column 6. Because the snake is 14 cells long we now have an additional 5 cells to fill to complete the sum from 45 to 68 and there are actually a lot of combinations you can use for that. But, and this is the important bit, you cannot re-use the two digits we placed in column 6 in that same column and you can also not put these on row 7 because they are already in column 7 and 9 (inside the 53-cage) and r7c8 is already occupied. First assuming that none of the three digits we know to be on the L-shape middle section of the snake and know to be digits 1-3-4 is repeated, the lowest value you can get from 5 cells is 2+5+6+7+8 which is 28 and we need only 23. Thus we know that the digit in r7c8 must be repeated in column 4. The minimum value we can then get from 5 cells is 1+2+5+6+7, which is 21 and well within the range where you can make it 23, but it shifts outside the range when you skip the 2 or the 5 (replacing it with an 8). Thus we have two known digits, 2 and 5, that are both in the snake ends **and** in the L-shape middle section and a third one that is either a 1 or a 3 (a 4 would make 24 minimum) somewhere in column 6 and r7c8. The 5 however cannot go in column 6 because of the knight's move, leaving only r7c7 and r7c9.
I've been following your channel for a week now and decided to give this a go last night.. I spent 2 hours and realized I made a mistake somewhere.. woke up this morning and tried again.. took me 3.5 hours but I GOT IT DONE!! Very happy!
It's phrases instead of frases, also it's supposed to be these, because you're talking about a plural of phrases. This is just for a singular. Also, a hole would be in the ground for example. In this context, it would mean whole :) just trying to help out as I assume you're not a native english speaker
I’ve been a subscriber and a patreon since long ago yet have rarely commented. Given that, I have to say, Simon, this *is indeed* the most impressive, beautiful, elegant, awe-inspiring logical solve I’ve ever seen - on the channel or otherwise. Your talent as a logician seemingly knows no bounds. All the superlatives for both you and ahaupt.
This puzzle is amazing. Not sure if it's been mentioned but from an early point it became clear that every digit had a symmetrical opposite that adds to 10 which took a while to confirm but really sped up the far end of the solve. The entire puzzle is balanced in that sense. Absolute genius!
I'll admit, I'm very bad at sudoku. I know this from several experiences on this channel. However, this was the most sobering. I spent maybe 20 minutes on this puzzle and laid exactly one line of logic with no placed digits. Within a minute and a half, Simon gave 4 different examples as to why my logic was wrong. Great stuff, really.
01:38:20 solve time // That was a fascinating puzzle. I used a slightly different breakthrough logic from the video solve; I won't bother going into the details, but using geometry + arithmetic, it's actually possible to determine early on that 2 + r7c4 = r3c6 + r4c6 + r5c6+ r6c6 + r6c5 With so many of the cells on the right hand side of the equation in the same 'block', it can further be deduced that r7c4 has to be the maximum value (r7c4 has to be 9), and the other cells have to be the minimum value (r3c6 & r6c5 have to be 1, [r4c6/r5c6/r6c6] have to be a 234 triple). Applying symmetry, we can also work out that [r4c4/r5c4/r6c4] have to be a 678 triple. It's slightly complicated and messy, so I'm not entirely sure if this was one of the intended paths, but I did find this puzzle significantly easier after discovering the trick. (I actually didn't notice the 'stripes' logic in c1/c2/c3 and c7/c8/c9 until watching the video)
I followed this same path at the start (only looking at the mirror of it), and asking what's the minimum and maximum of various combinations. I also never spotted the stripes that Simon used. I took considerably longer to solve though, 2hrs 51mins!
Always amazed by your solves. I'm surprised at 57:28 it sort of confirmed the pattern that squares mirrored across the center cell added up to 10 which could have made the solve even faster. Also the fact that it said "digits are balanced and frequencies of digits are as equal as possible". Appreciate your efforts of explaining every step through an hour long solve!
38:20 Wouldn't the "easy" solve here be that there can't be a 9 in r8c4 because there must be a 9 in c4 the 72-cage? Love when you upload long videos like this because then I can just relax and watch. The shorter videos give me some kind of hope that I too can solve the puzzle, which rarely is the case.
On the few occasions I spy something that Simon doesn't, I like to think it was the most important part of the solve. It never is, but I like to think that.
I did this one on my own and I'm incredibly proud. Took less than 24 hours with breaks for sleep and life and things. I made a journal entry of the logic so that I could restore if I made any mistakes. A beautiful puzzle. Now I have earned the ability to watch you do it too!
Interesting, the 2 you place at 45 minutes was my second digit after the center 5. It felt like the intended solution and was incredible to see - the 40 cage had to have either 1456789, or 2356789, and all of those values are eliminated from that one tile, which already had a 134 triple established in the box. In order to not eliminate everything, we learn the contents of the 40 cage and place the 2.
From start, if you add the 68, 53, 31 and 30 regions, you get 182, which is only 2 more than 4 square boxes. But those regions are quite 4 boxes: they miss only one cell on r7-c4, and have 5 cells more: r6-c5 and r3-c6 to r6-c6. The only way to add 2 with one cell less and 5 cells more, where 4 of them cannot repeat, is to put 9 in the missing cell and 1-2-3-4-1 in the 5 others. That gives two 1's and one 9, plus a 2-3-4 triplet. Then you can do the same logic to the other side to find two 9's, one 1 et another triplet 6-7-8.
This! I got this almost immediately, but then didn't have a clue how to continue it. Found a few more digits when I remembered the knight's move restraint, but then got stuck again.
@Cracking The Cryptic at 40:12 you said you were not sure what to make of that. I suggest it was the beautiful symmetry of what you had solved so far, with the triple 5s and the 1 9. I’m new to your channel and absolutely loving it. Get my brain working again after years of lazy. Thank you very much.
Another beautiful thing about this puzzle, Simon, is that for every number, it's mirror position's number always adds up to 10! For example, the number in the top right of the entire grid is a 3. It's mirror position along the grid is the bottom left which is a 7 (3 + 7 = 10). I noticed this around 1:00:00 when I saw that in the middle you had 2 brown dominoes and the top brown domino had 8 and 9 while the bottom domino had 1 and 2 such that they mirrored the 8 and 9 domino to give you 10 and 10! Absolutely marvelous!
My break-in (same logic for the other half): - Look at the right half of the grid with cages 30, 31, 68, 53. If we sum them up and deduct 4 sets of 45, we get that r7c4 - (r3c6 + r4c6 r5c6 r6c6 r65) = -2. There is only one way to do that, which is to put 9 in box 8, 1234 in box 5, and 1 in box 2. - Then this forces 30 and 31 to be (1234569 + 1234678). The other combination (1234578 1234579) does not work anymore because of geometry. Then things get significantly more manageable after this. I didn't spot the stripes though, nice catch by Simon.
There is so much to like about this channel. First, the enthusiasm, gratitude, and intelligence of the hosts. Second, they explain so well one can keep track (with the odd rewind), and third - the other commenters are delightful too. It's an oasis of sanity here - for which I am very grateful particularly during COVID-19
I found a nice shortcut to this puzzle. Notice that if you add up the values of every clue with its symmetrical pair, you get 10*the number of elements of the clue. This means that if there was a way to get a digit, by analogy, its 180 degrees symmetrical counterpart is 10 minus that digit. But then, the whole puzzle is symmetrical (in particular the 5th 3x3 square is a magic square).
I agree on the symmetry. Spotted this too, and used it to mirror every deduction made. It's not a magic square in box 5 though. Perimeter columns and rows do not sum to 15.
Some useful starting logic Simon missed (at least with the 27 mins I watched so far): the 30 and 31 boxes (and by symmetry the 39 and 40 boxes) can never both be missing the same digit, because then that digit would have to be in row 6 on both boxes 8 and 9. That reduces the possibilities so that 5 and 9 are missing from 31 cage, with 7 and 8 missing from 30 cage, which then reduces the possible positions for 5 so that the only way to get 3 5s in columns 789 is to duplicate a 5 in the snake shaped cage in columns 7 and 9. Edit: thats the logic I used for the 5 that Simon removes at 32:20. However, unlike him, I didn't finish the puzzle...
I find the following quite interesting, and it may have been mentioned here as well. For the disambiguating the 5s between r7c7 and r79c, there's another (though I'm surely deeply related) approach. Ignore the 5s in box 8 for a moment. If you place in r7c7 then you must place in r4c9 and r1c2 via the knight's moves combined with the known 5s in r5 and r3. Sudoku combined with the knight's move from r1c2 eliminates all of the possible 5s in the 40 cage.
Regarding symmetry, you can quite easily see that the solution to this puzzle is symmetric (right off the bat, so to speak). The trick is to realize that all the clues are symmetric, including the killer clues, so there could never be a unique way to break this symmetry. So either the solution is symmetric, or the solution is not unique, but comes in pairwise symmetric solutions, which we can safely assume is not the case. The way we can see that the killer clues are symmetric is to appreciate that each pair of symmetric cages sum to a total of 10 per pair of cells. For instance, the 30 and 40 cages are each 7 cells large and sum to 70. One way to think about it is to take the finished solution and subtract 5 from every cell, and from every killer clue (per cell in the cage). One would then get a valid sudoku variant over the numbers from -4 to +4, and the 30 and 40 cages would have killer clues -5 and 5 respectively, clearly symmetric under addition.
I was thinking the same thing. I so wish he'd done this rather than double-checking the symmetry every time he made progress. It would have been a shorter video. But whatever, I could do the symmetry proof pretty easily, but no way could I have solved that puzzle.
I quickly picked up on the 10 rule for this puzzle once some numbers other than 5 got started being put on the board. I kept saying aloud, "The paired square must be X because adding it to Y equals 10." I am completely surprised that Simon didn't pick up on it at all, from what I can tell. I know I am late for this reply, but I felt the need to make this comment regardless, and I virtually never make comments.
Great solve with one caveat: you ignore the colors you established, which could have given you the 5 much sooner. At 19:00 you mark where 5 can‘t go in columns 4 and 6. When you also establish that 5 has to go in the „snake“ shapes twice. But then you ignore the color symmetry you established: 5 has to go in columns 1 or 3 and 7 or 8 respectively as only their colors repeat in the shapes. That gives you a single purple cell in row 3 and a single blue cell in row 7, both containing the 5.
57:45 … that I was able to solve this in under an hour delights me to no end! One disclaimer: I made a guess at around the two-thirds mark, which led to the final answer. I did not prove uniqueness in my solve. Still … WHAT a puzzle! [EDIT: I went back to where I made my 'guess', and was able to prove why the other possibility could not be. I feel better now.]
At about the 20 minute mark, it is useful to start hammering on the 39 and 40 cages. The geometry meant that it was impossible for the 40 cage and the 39 cage to both be missing the same digit, so collectively they're missing {1,2,3,5}. Since r3c2 is a 6,7, or 9, we know it is duplicated into r4c5, and we get a 1235 quadruple across r3 columns 1, 3, 4, and 6, which places the 4 in r3 column 9.
This makes me want to see a great Sudoku puzzle from the creator's perspective. Instead of seeing it solved, we see it being created. Or better yet, we see CTC solve it and then a link to a video of it being created.
Suggestions for CTC Bingo: - That is unbelievable - My Goodness me - What an idea - We get the same on the other side / We can do the same on the other side - To make x we have to use x, x and x - What on earth am I meant to do (with this) - We can't put an x into any of those quares - So this has to be x, obviously [when no one else can see it] - Oh good grief
I absolutely loved this one. While you were using logic, I was looking at the amazing symetrical pattern. 9 was always opposite of 1, 2 opposite of 8, 3 opposite of 7 and 4 opposite of 8. The 5 in the middle was the first clue of this pattern. It's brilliant. And well solved.
Hi Simon, you mentioned that you weren't sure which colours to use. When you're colouring in boxes, I think the most important thing to do is to avoid using both red and green (using just one of either red or green is fine, just not both). Any other choices of colours should be fine for the most part, but red-green colourblindness is by far the most common! Love the channel btw!
"Any other choices of colours should be fine for the most part, but red-green colourblindness is by far the most common" Hard disagree here. Dealing with the most common form of a disability and ignoring the minority because they are not numerous is not a good way to approach universal design. Rather than designing around the most common form, he should design around the least common. For example, Yellow/Blue/Red is a tricolor that is easy to distinguish, whether one has difficulty with Red/Green, Yellow/Green, Brown/Green, Green/Grey, Purple/Blue, Purple/Pink, Red/Orange etc.
hahaha hilarious. 90% can see colour and something like 10% are red green blind so you *must* address that disability, but then you say the 2% that cant see blue don't need to be addressed. 'i draw a line here, but not there...'
46:51 It was at this moment that I hypothesized that the entire puzzle was symmetrical around the 5s: All 9s would be mirrored over the 180 rotation by 1s; all 8s by 2s; 7s by 3s; etc. Truly beautiful.
I found early success using the symmetry. The 40, 39, 72 and 69 cages (left set) take up the same space as the 30, 31, 68 and 53 cages (right set). From that, there are 2 things to notice. First, the left set cages add up to 36 more than the right set. Second, observe how the two sets of cages act in column 4, 5 and 6. Column 4, 5 and 6 must be differ by 36 between the left an right cages. This has a profound impact on the central box surrounding the given 5, as well as cells r3c6 and r7c4. Basically to account for the difference, the 4 cells of the left set must be 6, 7, 8 and 9, while the 4 cells of the right set must be 1, 2, 3 and 4. The rest of the difference force r3c6 to be a 1 and r7c4 to be a 9. This placement of 1 and 9 sets 1 and 9 in the central box.
@@maxscherzer9521 Likewise Max, likewise. To fair, while my start was much simpler, it still took 2 hours and 24 minutes, so Simon was still much faster. :)
@@winoodlesnoodles1984 , I'm having trouble figuring out if you found the same thing I found. I'm sure they are related. I added up the 30,31,68 and 53 to get 182, and noticed they nearly overlap boxes 3, 6, 8 and 9, which sum to 45*4=180. Analyzing the difference gave a 1's in r3c6 and r7c4, the 9 in r6c5, and the 2-3-4 triple in column 6 in box 5. Did we just do essentially the same sums in a slightly different order?
Simon, you've managed to let me forget I have a rotten flu for over an hour, and even made my poor fuzzy head work normal for a while, trying to follow your brilliant maths and logic! Thank you so much for this thrilling solve of an exquisite puzzle!
Simon does not need to apologize for long videos. I like seeing him tackle a really tough puzzle that gives him problems sometimes. We like to see him struggle because a lot of us struggle all the time with almost every puzzle.
This is the first puzzles where I spotted a number before he did and it was the one to crack the rest of the puzzle. I think I am getting better at understand. This channel has expanded my knowledge on puzzle solving. I will forever be thankful for that.
Your excitement and absolute /delight/ during these harder solves is contagious. Nothing manages to cheer me up quite as well as watching the "aha!" moments, even if they surpass my understanding. Thank you.
38:00 Simon going through super complex logic to rule out 9's. Forgets about the triple 9's right above the same cell staring at it ruling it out already xD
That was absolutely epic! I found that as 134 possibles spread over the right hand side of the grid by using 3 different colours you can identify around 5/6 mirrors for each. You can then quite early rule out 134 from r7c6 as it's seen by all 3 colours. That gives you the candidates for the 31 region which you can then use to start eliminating 2,6,8s nearby. Also, once that locks a 1234 into c6 the repeated digit in r7c8 for the 68 region has to be 1, otherwise you'd need to pair 3 with a 5 in c9 which would break the 5 already there, or 4 with another 4 so you'd have three 4s in the region. My brain now hurts :)
I love how you go about solving puzzles so much differently than I do. After solving a puzzle myself I love to go back and watch you solve the same puzzle to see how many different lines of logic can bring about the same solution! For such a beautiful puzzle such as this it seems even more striking and fascinating.
That is a fantastic puzzle and a great solve. That fact that it had so many logic steps that i would put in the "hard, but not ridiculous" category, but gave so little info back in return made it a fascinating watch. That's despite it being beyond my personal scope, albeit not for any particular step but for the fact that it'd probably take me at least 10 minutes to spot each one! (and that's me being kind to myself XD)
Kinda hard to do since these puzzles are ever changing and increasingly complex... Imagine a loved one completely baffled by us to the point that they need to say. "I must be losing my mind, this is brilliant!"
after a bit over an hour I managed to pause the video and finish the puzzle. I had all the possibilities for the 30/31/40/39 boxes written in from the start and taking away as you solved I found the 8 in the bottom centre box and the 4 in the top centre box early, and could disambiguate from there without any arithmetic (taking a very long time). Great puzzle.
Simon, you missed some math early on in the puzzle. After placing the 5, you should be able to place the 9 in the bottom middle area and the 1 in the top middle area. Also the 1 and 9 in the middle area. And pencil marks for the 678 and 234 in the middle area.
Here's how: add the four left cages together, then add the four right cages together. their difference is 36. This difference must entirely be captured by the difference in the middle cage, which is at most 20, and twice the difference between r7c4 and r3c6, which is at most 2*8 = 16. 20+16 = 36. So you have no degrees of freedom here. r7c4 = 9, r3c6 = 1, and in the middle cage the left group gets 6789 while the right group gets 1234.
Yeah, that's how I started this as well. I never even noticed the striped pattern until near the end! Its' really interesting to see Simon solve this in a completely different way to how I did it.
@@maxscherzer9521 Throughout the whole puzzle, there's symmetry between 1 and 9, 2 and 8, 3 and 7, and 4 and 6. The exact axis of rotation is a little screwy, but it's definitely there.
What a puzzle, Had no time to finish, but so nice to work on. I started quite different, in the 39 and 40 cages the only combo that can be missing is 2/3 in 40 cage and 1/5 in 39 cage. Then you can deduce that 72 has to have two times both 2 and 3 and therefore two 9's, which places a 9 in cel R4, C5, and another 9 in R7, C4, from there the 951 stack in the regions 2, 5 and 8 followed quickly. Thank you, wonderful work you guys are doing
I accidentally paused the video a little over an hour in. Probably took me about a minute to notice. I just thought Simon was just really focused. - You have to breathe, Simon. Blink. Anything. ... Oh! [unpause] I'm not a genius exactly.
It's incredible how many different symmetrical grids you can have while still creating difficult puzzles. Normally it's a shame that you essentially have to solve half of the puzzle for one like this, but this one is so difficult that it's probably more like the setter throwing you a bone rather than trivializing it.
Is it just me or did someone else realize once you get to minute (50:00) you realize that the values of the two squares that line up on each other when you rotate the grid 180 degrees always add up to 10 meaning 5 lands on 5 and 7 lands on 3. Using this logic you could solve the puzzle in 10 minutes after you realize this rather than the 20 minutes he took.
My goodness that is a monstrous puzzle. Usually when I don't know how to start I'll get a couple hints the video and take over from there, but I just never got to a point where I felt like I could do so. Making logical leap after logical leap while juggling cage and box sums...it's really quite astonishing that fatigue didn't really start showing until late in the video.
I'm 31 mins into the video and am surprised that Simon didn't notice the grid must be symmetric because all the clues are symmetric. That is, matching sums add up to exactly 10 times the number of cells. This immediately gives the 5 in the center and means each step can always be trivially mirrored.
Just recently found this channel. Love it! Did anyone see that the digits in top right and bottom left equal 10 and top left and bottom right equal 10 and it works that way throughout!
"I'm sorry if I've missed something obvious" You're kidding, right? I have to rewind and pause the video a half dozen times to follow along with the logic you're casually pulling out of your hat.
A great solve and the way pairs of oppositely positioned numbers all add to 10 throughout the grid is beautiful. Using that could have saved you a lot of time, but of course you couldn't know for sure it would work perfectly. Better to follow the logic.
The bingo is hilarious, but it's missing one key phrase: That is an x, and that is... completely useless. Edit: Just heard "So that is all stripey!" Someone make another bingo please.
There was another powerful hint in this. If you look at the 30&31 box they have to have the numbers 1,3,4 twice between them. This creates a lot "linked" boxes and helps clean up the board a bit. Same in reverse with the 39&40 box.
The symmetry of the puzzle left me breathless as I was hoping Simon could see the logic from the start when he established that it was a symmetrical puzzle. It was reinforced further down the puzzle as he firmly saw it as a symmetrical puzzle that applied the same logic from bottom to top or vice versa. Thank you for the beautiful puzzle that you have shown us once again Team CTC
32 seconds ago! Wow! Got in early... one hour eleven minutes... Ugh. Now I'm dreading this puzzle. Edit: Wow. 4 hours to solve Totally missed that the large cages had to contain every digit, and started by trying to exclude certain ones. Restart after an hour. I didn't do all of the maths that Simon did, though. It made my brain hurt just listening to him do it!
That was amazing beyond all expectations. A sudoku solve battle for the ages with geometric logic that had all our minds spinning. Your phrasing is excellent, it is your unique style and no amount of copying or quoting should concern whatsoever. Some of us are even picking up a bit of UK style lingo in passing :D.
A neat trick to begin the puzzle and get some 9s and 1s in the 3 central colums : try summing the killer boxes restricted to column 1-6, and substract the full square-boxes. You'll get a big constraint on the overlap with central box (and then same process on the right of the grid !)
18:07 That was my exact response when I get to this exact point haha 37:45 The pencil marks in the 72 box would give up that the 9 was impossible in the R8C4 (wouldn't it?)
One thing that I noticed right at the beginning on top of the symmetrical layout of the cages, was that the sum of any 2 opposite cages was 5 x the total number of cells in the 2 cages (so the 40 cage containing 7 cells + the 30 cages containing 7 cells added up to 5 x 14 etc.). So that with the 5 in the middle, does prove that this would be a symmetrical sudoku. I wasn't smart enough to get further than that lol but it might've cut your solve time by not having to repeat the logic on both sides in the earlier parts of the puzzle
At 37:00, when Simon is looking for a reason why r9c4, I was screaming for him to see his pencil marks in c4 which immediately eliminate the 9 from that cell. But it's still great to see how his brain works. This was just a phenomenal solve!! For the rest of the video, he kept saying that there must be loads of things that he's missing. I doubt that anyone could have figured those things out either.
I love how hes always confident in his reasoning and is actually never wrong. Doesnt make sense to me how he gets there but he solves the puzzle every time. The only time he got digits wrong was that one puzzle where he used guess and check but that was the strategy so no surprise it worked
Simon: try this puzzle, it just took me an hour to solve
Me: I kinda have to work next week
This comment is actually insane🤣🤣🤣
Me: Needs at minimum 2-3 times as much time to solve it
Simon: Please try the puzzle for youself
Also Simon: Makes a Video over an hour long and says only one of the testers could solve it at all...
This comment almost made me spit my mouthful of tea because I laughed so hard.
I just got done trying to solve it on stream... Took me an hour to realize the 5 in the middle of the grid! Spent a solid 3 hours before I gave up with about 6 digits in the grid...
svevo forget work just sudoku
"This 5 is powerful because it rules out 5 in all of the selected places. And that ofcourse, is completely useless"
- Simon Anthony, estd. 2020
"... bother."
Bobbins!
Scooby Doo
It wasn't completely useless - it placed the repeats in the corner cages. It was only mostly useless.
Missing from the bingo. :(
Please never ever stop using your catch phrases! They bring a smile every time I hear em
Yes, I had a laugh but it was with much love. Never change, Simon!
Agreed! i was waiting for them!
but today there are new and also marvellous phrases. Loved it so much. Even though i had no bingo. Close, but no : )
please fill them with #. we löve em. ´´they lüv? äm ^ ^ ?!
like ??? one on the 12... regüllär 7 ? 3s a gäng ? wüdevär ^^
"Oh please, please let it be a naked single" - Simon describing my dating life
this comment is underrated
or lack thereof. 😂
Simon: *has an epiphany which requires thinking 8 steps ahead in the 4th dimension taking into account every arithmetic rule known to man kind*
Puzzle: *gives one number in return*
Simon: "Oh bother."
Hey, at least it's a digit! in a video I watched recently (everything wrogn the 2nd or so), most of the time 3 mins of thinking gave 1-3 pencil markings :)
@@ClemensKatzer that video has had a lasting effect on simon, he says wrong as wrogn every now and then these days ... :D
I only watched him do it and I'm physically exhausted from the effort he put in. Great job.
5:44 "Straight off the bat, we are up and running"
6:18 "Now that, of course, is completely useless...bother"
6:30 "So where shall we look..."
7:34 "also not very helpful..."
10:18 "Sorry, I am going to stare at this a little bit longer..."
11:01 "Ah, now, now, I have been thinking about his incorrectly... Here is some logic..."
11:08 "Ah, that is fascinating"
12:47 ****NEW PHRASE ALERT**** "This is all stripey"
13:50 ****NEW PHRASE ALERT**** "I have got a very appetizing looking grid"
14:52 "Ah, now, now I have, ah, yes yes, yes"
14:58 "This is lovely geometry"
18:11 "Right, now what on earth am I meant to do with this"
23:16 "Is that in any way helpful.... ah it might be a little bit helpful"
28:25 "Its 28 minutes in and I've got one digit in the grid"
28:35 "Oh Good Grief"
30:10 "I think I am going mad!"
31:48 "What does this mean? I have no idea......Oh, no, I've got an idea, look..."
33:16 "Oh my goodness me. OH MY GOODNESS ME!... Watch This, WATCH THIS!"
33:34 "That is absolutely lovely!"
36:16 "Oh, now, hang on, I've just spotted something else..."
38:29 "Ah Yeah, This is it, this is it!"
40:12 "I don't know what I am meant to appreciate from that!"
42:32 "This is one of the most beautiful executions I can remember, and I am still miles away from finishing it"
46:55 "What a puzzle this is. Every single digit, its' like, you have to come up with, a like, whoa moment"
47:28 "I don't have a clue what I am meant to do now"
57:00 "my goodness me, what a puzzle this is!"
58:17 "So now what do we do? What Do we do NOW?
58:24 "I haven't go a scooby-doo!"
1:02:32 "This is driving me mad"
1:03:03 "And now I can't see the woods through the trees at all"
1:06:37 "I feel like I am being punched in the face repeatedly by this puzzle"
1:08:19 "Oh, is that right? Have we got a naked single?"
1:09:15 "Yes yes YES! This, THIS is the square"
1:10:33 "This might be the best solve I have ever done on this channel!"
1:10:56 "Wow, Wow, that is one of the greatest sudoku puzzles, one of the greatest puzzles I have ever had the privileged to try!"
Maybe the first CTC video I've seen where Simon doesn't say "disambiguate"...happy to be proven wrong if it's in there somewhere 🤗🤗
1:03:02 the phrase is "Can't see the wood for the trees", it's quite an old school idiom.
I salute your diligence
Bingo!
@@AWildBard what? how on earth. please share it.
The bingo card is missing "I have absolutely no idea where to start this puzzle, although wait, if you look here..." (with no pause between the two thoughts of course)
Bobbins is also missing
So is "I don't know what I'm meant to appreciate from this/what am I meant to appreciate from this..."
5:44 "Straight off the bat, we are up and running"
Almost 30 minutes of intense work later ...
34:35 Gets second digit
Also Simon: "do try it out"
Me: "Nope"
I love CTC because of how relaxing it is to watch. 38:10 THERE'S A 9 ABOVE IT SIMON, SEE THE DAMN PATTERN! 38:45 He sees a completely off-the-wall impossible piece of logic that resolves the same way and I throw my laptop across the room.
He does the same in two or three other places: I can see it and he takes 5 or more minutes and absolutely ridiculous logic to get the same result. Typical Simon.
Example being 4 in b7 because the 4 was missing in cage 72, and his reasoning involved 3 other boxes and 4 other cages and a chess move. Brilliant!
my eyes are just drawn to the ctc bingo card, let me just stare at this for a second. that is just gorgeous!!!
A brilliant constructor
Simon: do try it out.
Me: hahaha hahahahaha hahahahahahahaha hahahahahahahaha hahaha no thanks...
Yea... I'm afraid that's only 1/4th of the appropriate amount of laughter for this situation.
At 33:20, “I nearly swore...” This puzzle took you over an hour. It deserves a rash word or two.
I wonder what his vocabulary is, when the camera is off.... If you swear on YT you'll get demonized .
He wanted to say this is unfuckingbelievable 😂 im sad he didnt, even a bleep wouldve sent me through the roof laughing
It took me almost 6 hours, you can imagine how much I swore while solving...😅
@@timowilms8102 Kudos to you for not giving up. I didn't even try this because I've learnt that if a CTC video lasts more than 30 minutes it means that there's no way in hell I'm ever solving that.
Thank you Simon for teaching us how to be patient (1:11:42), how to trust that there must be a way out and that all that we need to do is enjoy the beauty in the problems we face (THAT IS ABSOLUTELY BEAUTIFUL!), and to appreciate this beauty every step in the way. Guys, regardless of the level of difficulty, Simon is showing us that every one of us can enjoy Sudoku, or any puzzle for that matter, if we take the time to appreciate that clicking moment when we figure something out every step of the way. The point is not to solve a difficult puzzle and get to the end of it. That would be ridiculous, I didn't just watch over an hour of video just to know if you will solve it or not, I watched the whole process. The point of life is not what you achieve/obtain in the end.. it is trusting the process and enjoying every challenge on the way. Heck, I bet more than half the people here are not even following the logic, Simon. They are just in it for the sheer joy that you emanate for every little pencil-mark you figure out.
I don't think I could've put it better myself. You're a brilliant combo guys. never give up what you do, and continue to show us the beauty of the journey. The destination (the solution) may be what you're ultimately aiming for, but it's the journey (how you solved it) that is really enjoyed.
Well said.
I myself would not be able to solve this puzzle, but it was fascinating to watch.
Also, most people just want to be left alone with a sudoku, and it's something "useless", and you guys are making it a social thing, and something beautiful
.
Time traveling Simon: Do try it out
Video: 1:11:42
Me: No thanks!
exactly. I had just finished my daily errands and then sat down in my comfy chair with the intention of solving the new puzzle that I knew would come in at any moment. Saw the clip's thumbnail showing 1h 11m and grabbed the popcorn and let this guy solving it instead of me. As much admiration I have for such brilliant constructors as quickly I nope away from them when I see the pros taking 70 minutes to solve the said puzzle(s) xD
Yeah I try the ones that take them 20 minutes and it usually takes me 2-4 hours and I'm pretty proud of myself. no way am I trying one that took him a full hour
It's certainly too hard for me (as are many), but I often pause his videos to study for a few minutes to see if I can see any next step(s).
Mostly, I don't, but sometimes I do. (And, sometimes I wrongly think I have!)
It doesn't have to be all or none.
The fact that every cell with it's 180 degree rotation partner sums to 10 is so deeply satisfying.
I spotted this, im not sure he did as he kept applying logic to re-solve the partners, if he had it might have shaved 10 minutes off the solve time :D i was ofc still a total passenger
@@chrisvarns he did spot it at some point, he said something along the lines of "this has to be an 8, but i will apply the logic"
I love this channel. It has logic, humor and I'm going to have a full bingo card at the end.
Watching this was amazing, like watching an Olympic event. You lost me fairly early on with the 5’s, but I stayed on. Several times you couldn’t see the forest for the “wood”, so my husband asked me who I was yelling at. When you finally cracked the puzzle, I thought you might faint on the floor. Thanks for taking us along on this journey - I just can’t get enough.
Let's see if I can help you with the 5s. The key is consistently applying the "even distribution" rule: you cannot re-use a digit unless you have used all other digits and successively you cannot use a digit a third time unless you have used all other digits twice. Thus a cage that has 12 cells contains 6 unique digits and 3 repeated digits. The additional consequence from this is that the 6 cells from the 14 cell "snake" that are inside the top right and centre right boxes must contain the non repeated digits from the 53-cage. The digits that **are** repeated in the 53-cage thus must be somewhere else on the 68-snake to complete the full 1-9 range, with one the positions known to be r7c8. The remaining two(!) digits can only go in column 6.
Because the snake is 14 cells long we now have an additional 5 cells to fill to complete the sum from 45 to 68 and there are actually a lot of combinations you can use for that. But, and this is the important bit, you cannot re-use the two digits we placed in column 6 in that same column and you can also not put these on row 7 because they are already in column 7 and 9 (inside the 53-cage) and r7c8 is already occupied. First assuming that none of the three digits we know to be on the L-shape middle section of the snake and know to be digits 1-3-4 is repeated, the lowest value you can get from 5 cells is 2+5+6+7+8 which is 28 and we need only 23. Thus we know that the digit in r7c8 must be repeated in column 4. The minimum value we can then get from 5 cells is 1+2+5+6+7, which is 21 and well within the range where you can make it 23, but it shifts outside the range when you skip the 2 or the 5 (replacing it with an 8). Thus we have two known digits, 2 and 5, that are both in the snake ends **and** in the L-shape middle section and a third one that is either a 1 or a 3 (a 4 would make 24 minimum) somewhere in column 6 and r7c8. The 5 however cannot go in column 6 because of the knight's move, leaving only r7c7 and r7c9.
"please, please let it be a naked single!" another one for context 1:08:20
Simon on Tinder 2020
😂😂😂
I feel like someone at this moment is putting together a "naked single" montage. At least I hope so...
I've been following your channel for a week now and decided to give this a go last night.. I spent 2 hours and realized I made a mistake somewhere.. woke up this morning and tried again.. took me 3.5 hours but I GOT IT DONE!! Very happy!
"That's more bingo, sorry!"
I truly love you Simon
Simon: ‘‘ I’m now going to try deliberately not to use any of this frases ’’
Also Simon: uses them during the hole puzzle
It's phrases instead of frases, also it's supposed to be these, because you're talking about a plural of phrases. This is just for a singular. Also, a hole would be in the ground for example. In this context, it would mean whole :) just trying to help out as I assume you're not a native english speaker
xXxIronicName420xXx I love this
xXxIronicName420xXx I’m definitely not a native speaker lol
Thank for the help tho
I’ve been a subscriber and a patreon since long ago yet have rarely commented. Given that, I have to say, Simon, this *is indeed* the most impressive, beautiful, elegant, awe-inspiring logical solve I’ve ever seen - on the channel or otherwise. Your talent as a logician seemingly knows no bounds. All the superlatives for both you and ahaupt.
This puzzle is amazing. Not sure if it's been mentioned but from an early point it became clear that every digit had a symmetrical opposite that adds to 10 which took a while to confirm but really sped up the far end of the solve. The entire puzzle is balanced in that sense. Absolute genius!
I cracked up when he said 'I’ve got a very appetizing grid, and im sure that’s not on the bingo card!'
I busted out in laughter at that. So funny.
I'll admit, I'm very bad at sudoku. I know this from several experiences on this channel. However, this was the most sobering. I spent maybe 20 minutes on this puzzle and laid exactly one line of logic with no placed digits. Within a minute and a half, Simon gave 4 different examples as to why my logic was wrong. Great stuff, really.
01:38:20 solve time // That was a fascinating puzzle.
I used a slightly different breakthrough logic from the video solve; I won't bother going into the details, but using geometry + arithmetic, it's actually possible to determine early on that
2 + r7c4 = r3c6 + r4c6 + r5c6+ r6c6 + r6c5
With so many of the cells on the right hand side of the equation in the same 'block', it can further be deduced that r7c4 has to be the maximum value (r7c4 has to be 9), and the other cells have to be the minimum value (r3c6 & r6c5 have to be 1, [r4c6/r5c6/r6c6] have to be a 234 triple). Applying symmetry, we can also work out that [r4c4/r5c4/r6c4] have to be a 678 triple.
It's slightly complicated and messy, so I'm not entirely sure if this was one of the intended paths, but I did find this puzzle significantly easier after discovering the trick. (I actually didn't notice the 'stripes' logic in c1/c2/c3 and c7/c8/c9 until watching the video)
I followed this same path at the start (only looking at the mirror of it), and asking what's the minimum and maximum of various combinations. I also never spotted the stripes that Simon used. I took considerably longer to solve though, 2hrs 51mins!
Always amazed by your solves. I'm surprised at 57:28 it sort of confirmed the pattern that squares mirrored across the center cell added up to 10 which could have made the solve even faster. Also the fact that it said "digits are balanced and frequencies of digits are as equal as possible". Appreciate your efforts of explaining every step through an hour long solve!
38:20 Wouldn't the "easy" solve here be that there can't be a 9 in r8c4 because there must be a 9 in c4 the 72-cage?
Love when you upload long videos like this because then I can just relax and watch. The shorter videos give me some kind of hope that I too can solve the puzzle, which rarely is the case.
Yep, same thing with the 1 in column 7. ... and that was basically the only thing I caught in this puzzle that Simon did not.
Commented the same thing, now i see many more also noticed that
glad someone else spotted it, i was tearing my hair out
On the few occasions I spy something that Simon doesn't, I like to think it was the most important part of the solve. It never is, but I like to think that.
I totally missed that too, nice catch
I did this one on my own and I'm incredibly proud. Took less than 24 hours with breaks for sleep and life and things. I made a journal entry of the logic so that I could restore if I made any mistakes. A beautiful puzzle. Now I have earned the ability to watch you do it too!
Interesting, the 2 you place at 45 minutes was my second digit after the center 5. It felt like the intended solution and was incredible to see - the 40 cage had to have either 1456789, or 2356789, and all of those values are eliminated from that one tile, which already had a 134 triple established in the box. In order to not eliminate everything, we learn the contents of the 40 cage and place the 2.
From start, if you add the 68, 53, 31 and 30 regions, you get 182, which is only 2 more than 4 square boxes. But those regions are quite 4 boxes: they miss only one cell on r7-c4, and have 5 cells more: r6-c5 and r3-c6 to r6-c6.
The only way to add 2 with one cell less and 5 cells more, where 4 of them cannot repeat, is to put 9 in the missing cell and 1-2-3-4-1 in the 5 others.
That gives two 1's and one 9, plus a 2-3-4 triplet.
Then you can do the same logic to the other side to find two 9's, one 1 et another triplet 6-7-8.
This!
I got this almost immediately, but then didn't have a clue how to continue it. Found a few more digits when I remembered the knight's move restraint, but then got stuck again.
@Cracking The Cryptic at 40:12 you said you were not sure what to make of that. I suggest it was the beautiful symmetry of what you had solved so far, with the triple 5s and the 1 9. I’m new to your channel and absolutely loving it. Get my brain working again after years of lazy. Thank you very much.
Another beautiful thing about this puzzle, Simon, is that for every number, it's mirror position's number always adds up to 10! For example, the number in the top right of the entire grid is a 3. It's mirror position along the grid is the bottom left which is a 7 (3 + 7 = 10). I noticed this around 1:00:00 when I saw that in the middle you had 2 brown dominoes and the top brown domino had 8 and 9 while the bottom domino had 1 and 2 such that they mirrored the 8 and 9 domino to give you 10 and 10! Absolutely marvelous!
My break-in (same logic for the other half):
- Look at the right half of the grid with cages 30, 31, 68, 53. If we sum them up and deduct 4 sets of 45, we get that r7c4 - (r3c6 + r4c6 r5c6 r6c6 r65) = -2. There is only one way to do that, which is to put 9 in box 8, 1234 in box 5, and 1 in box 2.
- Then this forces 30 and 31 to be (1234569 + 1234678). The other combination (1234578 1234579) does not work anymore because of geometry.
Then things get significantly more manageable after this. I didn't spot the stripes though, nice catch by Simon.
There is so much to like about this channel. First, the enthusiasm, gratitude, and intelligence of the hosts. Second, they explain so well one can keep track (with the odd rewind), and third - the other commenters are delightful too. It's an oasis of sanity here - for which I am very grateful particularly during COVID-19
I found a nice shortcut to this puzzle.
Notice that if you add up the values of every clue with its symmetrical pair,
you get 10*the number of elements of the clue. This means that if there was a way
to get a digit, by analogy, its 180 degrees symmetrical counterpart is 10 minus that
digit. But then, the whole puzzle is symmetrical (in particular the 5th 3x3 square is
a magic square).
I agree on the symmetry. Spotted this too, and used it to mirror every deduction made. It's not a magic square in box 5 though. Perimeter columns and rows do not sum to 15.
Some useful starting logic Simon missed (at least with the 27 mins I watched so far): the 30 and 31 boxes (and by symmetry the 39 and 40 boxes) can never both be missing the same digit, because then that digit would have to be in row 6 on both boxes 8 and 9. That reduces the possibilities so that 5 and 9 are missing from 31 cage, with 7 and 8 missing from 30 cage, which then reduces the possible positions for 5 so that the only way to get 3 5s in columns 789 is to duplicate a 5 in the snake shaped cage in columns 7 and 9. Edit: thats the logic I used for the 5 that Simon removes at 32:20. However, unlike him, I didn't finish the puzzle...
I find the following quite interesting, and it may have been mentioned here as well. For the disambiguating the 5s between r7c7 and r79c, there's another (though I'm surely deeply related) approach. Ignore the 5s in box 8 for a moment. If you place in r7c7 then you must place in r4c9 and r1c2 via the knight's moves combined with the known 5s in r5 and r3. Sudoku combined with the knight's move from r1c2 eliminates all of the possible 5s in the 40 cage.
"I feel like I've been punched in the face repeatedly by this puzzle".
-Simon Anthony 2020
I'm only part-way through this but I'm already blown away by this puzzle. What insane logic!
Regarding symmetry, you can quite easily see that the solution to this puzzle is symmetric (right off the bat, so to speak). The trick is to realize that all the clues are symmetric, including the killer clues, so there could never be a unique way to break this symmetry. So either the solution is symmetric, or the solution is not unique, but comes in pairwise symmetric solutions, which we can safely assume is not the case.
The way we can see that the killer clues are symmetric is to appreciate that each pair of symmetric cages sum to a total of 10 per pair of cells. For instance, the 30 and 40 cages are each 7 cells large and sum to 70. One way to think about it is to take the finished solution and subtract 5 from every cell, and from every killer clue (per cell in the cage). One would then get a valid sudoku variant over the numbers from -4 to +4, and the 30 and 40 cages would have killer clues -5 and 5 respectively, clearly symmetric under addition.
wow, thanks for the explanation!
I was thinking the same thing. I so wish he'd done this rather than double-checking the symmetry every time he made progress. It would have been a shorter video. But whatever, I could do the symmetry proof pretty easily, but no way could I have solved that puzzle.
I quickly picked up on the 10 rule for this puzzle once some numbers other than 5 got started being put on the board. I kept saying aloud, "The paired square must be X because adding it to Y equals 10." I am completely surprised that Simon didn't pick up on it at all, from what I can tell. I know I am late for this reply, but I felt the need to make this comment regardless, and I virtually never make comments.
Great solve with one caveat: you ignore the colors you established, which could have given you the 5 much sooner. At 19:00 you mark where 5 can‘t go in columns 4 and 6. When you also establish that 5 has to go in the „snake“ shapes twice. But then you ignore the color symmetry you established: 5 has to go in columns 1 or 3 and 7 or 8 respectively as only their colors repeat in the shapes. That gives you a single purple cell in row 3 and a single blue cell in row 7, both containing the 5.
57:45 … that I was able to solve this in under an hour delights me to no end!
One disclaimer: I made a guess at around the two-thirds mark, which led to the final answer. I did not prove uniqueness in my solve.
Still … WHAT a puzzle!
[EDIT: I went back to where I made my 'guess', and was able to prove why the other possibility could not be. I feel better now.]
Under an hour? That's unique enough even if it wasn't a proof!
At about the 20 minute mark, it is useful to start hammering on the 39 and 40 cages. The geometry meant that it was impossible for the 40 cage and the 39 cage to both be missing the same digit, so collectively they're missing {1,2,3,5}. Since r3c2 is a 6,7, or 9, we know it is duplicated into r4c5, and we get a 1235 quadruple across r3 columns 1, 3, 4, and 6, which places the 4 in r3 column 9.
This makes me want to see a great Sudoku puzzle from the creator's perspective. Instead of seeing it solved, we see it being created. Or better yet, we see CTC solve it and then a link to a video of it being created.
This puzzle is in fact a complete mirror around the 5 with each opposing cells adding to 10!! Fascinating !
The bingo is one of the reason we love you, don't be sorry for that!
Amazing. This is why I came to the channel, and why I stayed.
You and ahaupt (and Mark) deserve more praise than I can give.
Suggestions for CTC Bingo:
- That is unbelievable
- My Goodness me
- What an idea
- We get the same on the other side / We can do the same on the other side
- To make x we have to use x, x and x
- What on earth am I meant to do (with this)
- We can't put an x into any of those quares
- So this has to be x, obviously [when no one else can see it]
- Oh good grief
And lest we forget "the snake can't touch itself orthogonally"
And that is...
Completely useless
Look here look.
Now, what to do next?
I absolutely loved this one. While you were using logic, I was looking at the amazing symetrical pattern. 9 was always opposite of 1, 2 opposite of 8, 3 opposite of 7 and 4 opposite of 8. The 5 in the middle was the first clue of this pattern. It's brilliant. And well solved.
Hi Simon, you mentioned that you weren't sure which colours to use. When you're colouring in boxes, I think the most important thing to do is to avoid using both red and green (using just one of either red or green is fine, just not both). Any other choices of colours should be fine for the most part, but red-green colourblindness is by far the most common! Love the channel btw!
To that effect also avoid using green and yellow. They look pretty much identical with red/green deficiency.
"Any other choices of colours should be fine for the most part, but red-green colourblindness is by far the most common" Hard disagree here.
Dealing with the most common form of a disability and ignoring the minority because they are not numerous is not a good way to approach universal design. Rather than designing around the most common form, he should design around the least common. For example, Yellow/Blue/Red is a tricolor that is easy to distinguish, whether one has difficulty with Red/Green, Yellow/Green, Brown/Green, Green/Grey, Purple/Blue, Purple/Pink, Red/Orange etc.
hahaha hilarious. 90% can see colour and something like 10% are red green blind so you *must* address that disability, but then you say the 2% that cant see blue don't need to be addressed. 'i draw a line here, but not there...'
46:51 It was at this moment that I hypothesized that the entire puzzle was symmetrical around the 5s: All 9s would be mirrored over the 180 rotation by 1s; all 8s by 2s; 7s by 3s; etc. Truly beautiful.
I found early success using the symmetry. The 40, 39, 72 and 69 cages (left set) take up the same space as the 30, 31, 68 and 53 cages (right set). From that, there are 2 things to notice. First, the left set cages add up to 36 more than the right set. Second, observe how the two sets of cages act in column 4, 5 and 6. Column 4, 5 and 6 must be differ by 36 between the left an right cages. This has a profound impact on the central box surrounding the given 5, as well as cells r3c6 and r7c4. Basically to account for the difference, the 4 cells of the left set must be 6, 7, 8 and 9, while the 4 cells of the right set must be 1, 2, 3 and 4. The rest of the difference force r3c6 to be a 1 and r7c4 to be a 9. This placement of 1 and 9 sets 1 and 9 in the central box.
Yep, saw the same. This had to be the intended path.
Normally I'm much worse than Simon at these puzzles.
@@maxscherzer9521 Likewise Max, likewise. To fair, while my start was much simpler, it still took 2 hours and 24 minutes, so Simon was still much faster. :)
@@winoodlesnoodles1984 , I'm having trouble figuring out if you found the same thing I found. I'm sure they are related. I added up the 30,31,68 and 53 to get 182, and noticed they nearly overlap boxes 3, 6, 8 and 9, which sum to 45*4=180. Analyzing the difference gave a 1's in r3c6 and r7c4, the 9 in r6c5, and the 2-3-4 triple in column 6 in box 5.
Did we just do essentially the same sums in a slightly different order?
@@dmdeemer Yes. Slightly different order, but the exact same results. Great spot!
Simon, you've managed to let me forget I have a rotten flu for over an hour, and even made my poor fuzzy head work normal for a while, trying to follow your brilliant maths and logic! Thank you so much for this thrilling solve of an exquisite puzzle!
“Un....oh, almost swore there. Unbelievable.”
Honestly, favorite moment from all the videos I’ve seen so far.
Simon does not need to apologize for long videos. I like seeing him tackle a really tough puzzle that gives him problems sometimes. We like to see him struggle because a lot of us struggle all the time with almost every puzzle.
Simon: Am i going mad?
I think I'm going mad.
And you want us to try it out?
No naah, thank you 😂
This puzzle is so beautiful. The complete symmetry paired with the fact that the sum of each symmetrical pair of numbers is ten.
I have to say i absolutely love the community on and around your channel!
This is the first puzzles where I spotted a number before he did and it was the one to crack the rest of the puzzle. I think I am getting better at understand. This channel has expanded my knowledge on puzzle solving. I will forever be thankful for that.
33:19 I've never seen something that amazed Simon that much. Now I really want to hear Simon swear.
Your excitement and absolute /delight/ during these harder solves is contagious. Nothing manages to cheer me up quite as well as watching the "aha!" moments, even if they surpass my understanding. Thank you.
38:00 Simon going through super complex logic to rule out 9's. Forgets about the triple 9's right above the same cell staring at it ruling it out already xD
That was absolutely epic! I found that as 134 possibles spread over the right hand side of the grid by using 3 different colours you can identify around 5/6 mirrors for each. You can then quite early rule out 134 from r7c6 as it's seen by all 3 colours. That gives you the candidates for the 31 region which you can then use to start eliminating 2,6,8s nearby. Also, once that locks a 1234 into c6 the repeated digit in r7c8 for the 68 region has to be 1, otherwise you'd need to pair 3 with a 5 in c9 which would break the 5 already there, or 4 with another 4 so you'd have three 4s in the region. My brain now hurts :)
This is officially the second an-hour video I’ve watched on RUclips and it is no coincidence that they are both Cracking The Cryptic’s
I wish I could count the number of hour+ videos I've watched... :(
You must be new on this site
darek4488 I’ve never watched anything more than 30 mins on youtube except these so 🤗
I love how you go about solving puzzles so much differently than I do. After solving a puzzle myself I love to go back and watch you solve the same puzzle to see how many different lines of logic can bring about the same solution! For such a beautiful puzzle such as this it seems even more striking and fascinating.
THIS! IS!! BRILLIANT!!! Really one of the greatest of the greatest puzzle I've ever seen!
I'm not sorry I've spent an hour of my life watching this!
That is a fantastic puzzle and a great solve. That fact that it had so many logic steps that i would put in the "hard, but not ridiculous" category, but gave so little info back in return made it a fascinating watch. That's despite it being beyond my personal scope, albeit not for any particular step but for the fact that it'd probably take me at least 10 minutes to spot each one! (and that's me being kind to myself XD)
Where can i find myself someone that reacts to me existing the way simon reacting to every game he plays
Kinda hard to do since these puzzles are ever changing and increasingly complex... Imagine a loved one completely baffled by us to the point that they need to say. "I must be losing my mind, this is brilliant!"
after a bit over an hour I managed to pause the video and finish the puzzle. I had all the possibilities for the 30/31/40/39 boxes written in from the start and taking away as you solved I found the 8 in the bottom centre box and the 4 in the top centre box early, and could disambiguate from there without any arithmetic (taking a very long time). Great puzzle.
Simon, you missed some math early on in the puzzle. After placing the 5, you should be able to place the 9 in the bottom middle area and the 1 in the top middle area. Also the 1 and 9 in the middle area. And pencil marks for the 678 and 234 in the middle area.
Here's how: add the four left cages together, then add the four right cages together. their difference is 36. This difference must entirely be captured by the difference in the middle cage, which is at most 20, and twice the difference between r7c4 and r3c6, which is at most 2*8 = 16. 20+16 = 36.
So you have no degrees of freedom here. r7c4 = 9, r3c6 = 1, and in the middle cage the left group gets 6789 while the right group gets 1234.
@@maxscherzer9521 That's how I solved this. I would have posted myself, but you beat me to it.
Yeah, that's how I started this as well. I never even noticed the striped pattern until near the end! Its' really interesting to see Simon solve this in a completely different way to how I did it.
You guys solved it?
@@maxscherzer9521 Throughout the whole puzzle, there's symmetry between 1 and 9, 2 and 8, 3 and 7, and 4 and 6. The exact axis of rotation is a little screwy, but it's definitely there.
What a puzzle,
Had no time to finish, but so nice to work on.
I started quite different, in the 39 and 40 cages the only combo that can be missing is 2/3 in 40 cage and 1/5 in 39 cage.
Then you can deduce that 72 has to have two times both 2 and 3 and therefore two 9's, which places a 9 in cel R4, C5, and another 9 in R7, C4, from there the 951 stack in the regions 2, 5 and 8 followed quickly.
Thank you, wonderful work you guys are doing
I accidentally paused the video a little over an hour in. Probably took me about a minute to notice. I just thought Simon was just really focused.
- You have to breathe, Simon. Blink. Anything. ... Oh! [unpause]
I'm not a genius exactly.
It's incredible how many different symmetrical grids you can have while still creating difficult puzzles.
Normally it's a shame that you essentially have to solve half of the puzzle for one like this, but this one is so difficult that it's probably more like the setter throwing you a bone rather than trivializing it.
Is it just me or did someone else realize once you get to minute (50:00) you realize that the values of the two squares that line up on each other when you rotate the grid 180 degrees always add up to 10 meaning 5 lands on 5 and 7 lands on 3. Using this logic you could solve the puzzle in 10 minutes after you realize this rather than the 20 minutes he took.
My goodness that is a monstrous puzzle. Usually when I don't know how to start I'll get a couple hints the video and take over from there, but I just never got to a point where I felt like I could do so. Making logical leap after logical leap while juggling cage and box sums...it's really quite astonishing that fatigue didn't really start showing until late in the video.
42:02 Can we appreciate the key lime pi in the top right corner?
I'm 31 mins into the video and am surprised that Simon didn't notice the grid must be symmetric because all the clues are symmetric. That is, matching sums add up to exactly 10 times the number of cells. This immediately gives the 5 in the center and means each step can always be trivially mirrored.
I think of Paul Hogan every time he says "That's not a nine. This is a nine."
Just recently found this channel. Love it! Did anyone see that the digits in top right and bottom left equal 10 and top left and bottom right equal 10 and it works that way throughout!
"I'm sorry if I've missed something obvious"
You're kidding, right? I have to rewind and pause the video a half dozen times to follow along with the logic you're casually pulling out of your hat.
A great solve and the way pairs of oppositely positioned numbers all add to 10 throughout the grid is beautiful. Using that could have saved you a lot of time, but of course you couldn't know for sure it would work perfectly. Better to follow the logic.
The bingo is hilarious, but it's missing one key phrase:
That is an x, and that is... completely useless.
Edit: Just heard "So that is all stripey!" Someone make another bingo please.
Don't forget "bobbins!"
Said nonetheless with as much fascinated wonder as he would for a clue that cracks open the whole puzzle
The one that really is missing is:
"Can we go further than that?"
Hey we have to leave the man something he's allowed to say.
Answers on a postcard, please!
There was another powerful hint in this. If you look at the 30&31 box they have to have the numbers 1,3,4 twice between them. This creates a lot "linked" boxes and helps clean up the board a bit. Same in reverse with the 39&40 box.
I've never seen a sudoku put me in the mood for Neapolitan ice cream before.
The symmetry of the puzzle left me breathless as I was hoping Simon could see the logic from the start when he established that it was a symmetrical puzzle. It was reinforced further down the puzzle as he firmly saw it as a symmetrical puzzle that applied the same logic from bottom to top or vice versa. Thank you for the beautiful puzzle that you have shown us once again Team CTC
32 seconds ago! Wow! Got in early...
one hour eleven minutes... Ugh. Now I'm dreading this puzzle.
Edit: Wow. 4 hours to solve
Totally missed that the large cages had to contain every digit, and started by trying to exclude certain ones. Restart after an hour.
I didn't do all of the maths that Simon did, though. It made my brain hurt just listening to him do it!
That was amazing beyond all expectations. A sudoku solve battle for the ages with geometric logic that had all our minds spinning. Your phrasing is excellent, it is your unique style and no amount of copying or quoting should concern whatsoever. Some of us are even picking up a bit of UK style lingo in passing :D.
I get a little happy feeling everytime Simon says (no jokes please), "Here, look."
A neat trick to begin the puzzle and get some 9s and 1s in the 3 central colums : try summing the killer boxes restricted to column 1-6, and substract the full square-boxes. You'll get a big constraint on the overlap with central box (and then same process on the right of the grid !)
Did anyone have "I'm being punched in the face by this puzzle" on their bingo card?
The way the more Simon solved it, the more symmetrical it became, was stunning to view.
18:07 That was my exact response when I get to this exact point haha
37:45 The pencil marks in the 72 box would give up that the 9 was impossible in the R8C4 (wouldn't it?)
Congrats on the solve! I don't think I have the wits, knowledge or patience to complete it! It looks amazingly constructed, so props to the setter!
By the way, the sum of two symmetrical cages here is exactly 10 multiplied by the number of cells in one cage.
which means that the 180 rotation of this puzzle, overlapped, gets you a 10 in every cell
One thing that I noticed right at the beginning on top of the symmetrical layout of the cages, was that the sum of any 2 opposite cages was 5 x the total number of cells in the 2 cages (so the 40 cage containing 7 cells + the 30 cages containing 7 cells added up to 5 x 14 etc.). So that with the 5 in the middle, does prove that this would be a symmetrical sudoku. I wasn't smart enough to get further than that lol but it might've cut your solve time by not having to repeat the logic on both sides in the earlier parts of the puzzle
Simon: This square is a 4.....
Me: I'm still trying to understand the rules....
im still trying to figure out why its a 4
@@tamsel814 which part is that? maybe I can say
At 37:00, when Simon is looking for a reason why r9c4, I was screaming for him to see his pencil marks in c4 which immediately eliminate the 9 from that cell. But it's still great to see how his brain works. This was just a phenomenal solve!! For the rest of the video, he kept saying that there must be loads of things that he's missing. I doubt that anyone could have figured those things out either.
Makes me laugh when there's an apology at the end for the video length. I see an hour upload and think "Nice, cuppa with this one" 👍
I love how hes always confident in his reasoning and is actually never wrong. Doesnt make sense to me how he gets there but he solves the puzzle every time. The only time he got digits wrong was that one puzzle where he used guess and check but that was the strategy so no surprise it worked