I finished in 63 minutes. The brilliance of this puzzle is astounding! Figuring out that greens had to be high based on column 6 was incredible to discover. This was some incredible setting. I liked this very much. Great Puzzle!
Thank you Mark. This is the first time I have beaten you, and by nearly a quarter of an hour. I loved the puzzle. I haven't watched your solve, but now, reading some comments it seems that appreciating right at the start that the only possible total for the equal sums was 9 was the key to getting off to a decent start.
If purple is high then a tip of thermo on the row is 5 making its bulb 1 which forces the sum line in box five to at least 2, 3, 7, 8, making yellow a 10.
This is the best way. My way was slightly more complex, but it was easy enough for me to grasp it quickly (and I have a much smaller neural mass storage unit than Mark). In short, if *purple* is high, you get 5 low digits in *box 4.* I explained my logic steps in a separate comment.
33:04. Didn't take too long to figure out which on green line were high and which were low thanks to the thermo with bulb in box 8. Using colours for high and low helped greatly. Quite a bit of eliminating candidates as opposed to figuring out which specific digit. Which I loved because you had to eliminate one to eliminate another further away which then made another one solve. Loved the bouncing around which made it enjoyable.
Mark, what a riveting video and solve - absolutely loved it. Thank you! A few specifics: I am glad you said what you said about bifurcating. I suspect that commenters on this and other videos who mention or accuse you of bifurcating have not tried to solve the puzzle themselves in some cases, and have not had to work though the many possible pathways that such a complex puzzle presents in order to decide how to move forward. Your 'look aheads' always seem essential to me in gaining understanding of the implications of the rules and markings in the grid. Another thing: I so appreciate and love that you (and Simon) solve puzzles live and "cold" as it were - you have not seen it before, you are not giving us a best or most efficient pathway through a puzzle, but you are approaching it just as we do when we click on the link. Your best is fantastic, impressive, inspiring - thank you so much for bringing us a video (plus a Wordle, plus other things) every single day. What a privilege to watch your mind work.
21 MInutes. (Fine- 21.03 minutes). Mark's solve was a lot harder than it should have been- once you know the "blues" in box five are low, 6 can't be on the oranges in box five (as it can't be next to two 1's), which gives you the "yellows" as well. Loved the puzzle.
I needed the prompt from Mark to consider what would happen if r5c46 were the high digits in the central box, and then saw how that forces one of the thermos to end with a 5 and therefore start with a 1, which breaks r46c5 as that also needs a 1, which sets the parity on the green and blue lines. From there it was a fairly attritional process to finish in 35 minutes. This definitely felt like Mark was missing a _lot_ of sudoku and not following through on deductions (particularly where the same logic applies in multiple places).
I solved it from the clue Mark gave me that 3 on a whisper corner creates an 89 pair that looks at yellow. He used it to solve parity, but didn't use it once he had blue on the whisper.
Edit: I'm talking nonsense, don't listen to me. Read my reply to see how I messed up, at least a few other people messed up in the same way though. 13:45 for me. Best "solve-time to video-time" ratio I've ever had, never to be repeated! Impressive that Mark managed to solve it in such a different way, Equal Sum lines were surely the intended break-in. Each pair in box 5 is one high + one low, and there's only one corner digit that can make that work twice in one box.
@@ruckmanikrishnan4221 I knew I'd be brought back down to Earth somehow! You're absolutely correct, I excluded 2-6 because I was confused by the crossed lines, 2-6 wouldn't work on whispers but are fine on equal sums. I had a sneaking feeling I had done something wrong, thank you for highlighting it. At least I only wasted 13 minutes on a wrong solution, not a full hour.
It would be helpful to other people reading comments if you were to edit your original comment to mention that you had made an error. It is discouraging to me to read comments that mention an alleged better way through a puzzle, only to read replies where it is acknowledged that the better way was not correct (or not the only way). Thanks for acknowledging it in the replies - more helpful to also have it in your original comment.
27 minutes. I felt there was a pretty easy proof for the 4 9s on the equal sums line, I had those filled in during the first minute, I think that gave me the unexpected head start to get a rare better speed than the legand himself. I don't get that often, I'll enjoy it while it lasts.
what was it? I only was able to get 8/9 penciled in those boxes until very near the end of the puzzle. I can't help but feel you might have made an unsupported conclusion, as I can't think of any way to prove it that early.
Nice puzzle. I almost didn’t attempt it when I saw Mark’s time. Anything over 40 minutes is usually too hard for me. Glad I did give it a go. It wasn’t too hard at all. Don’t understand why Mark took so long. Not like him to miss stuff; like that 2/3 pair in box 6 which sorted r3c7.
Rules: 02:02 Let's Get Cracking: 03:09 What about this video's Top Tier Simarkisms?! Goodliffing: 1x (04:00) Cooking with Gas: 1x (56:05) Phistomefel: 1x (04:21) And how about this video's Simarkisms?! Ah: 7x (11:16, 17:42, 21:51, 26:53, 33:33, 36:29, 53:09) Proof: 5x (08:09, 11:26, 11:31, 13:35, 13:46) In Fact: 5x (08:12, 31:47, 36:50, 37:22, 40:39) What Does This Mean?: 4x (06:08, 44:49, 52:49, 54:58) Goodness: 3x (29:04, 35:30, 46:40) Sorry: 3x (05:37, 19:37, 35:41) Clever: 3x (57:01, 57:04, 57:04) Obviously: 3x (47:49, 50:39, 51:32) Wow: 3x (50:59, 55:30, 58:06) Bother: 1x (20:27) Apologies: 1x (56:57) Beautiful: 1x (32:28) Brilliant: 1x (00:34) Extraordinary: 1x (58:24) By Sudoku: 1x (56:27) Shenanigans: 1x (00:19) Progress: 1x (54:19) Symmetry: 1x (20:05) Weird: 1x (41:22) Most popular number(>9), digit and colour this video: Seventy Eight (6 mentions) One (114 mentions) Green (39 mentions) Antithesis Battles: High (29) - Low (21) Even (5) - Odd (0) Higher (7) - Lower (1) Outside (2) - Inside (0) Row (18) - Column (15) 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!
The best way to figure out the polarity of the *German whisper line* was described in this section by *Mn0ty* My logic was slightly more complex, but it was easy enough for me to grasp it quickly (and I have a much smaller neural mass storage unit than Mark). If *purple* is high, you get too many low digits in *box 4:* 🔹By German whisper logic, the *green* cell (r4c3) is low 🔹By sudoku, *r5c2* and *r5c3* are low 🔹By thermo logic, *r6c1* and *r6c2* are also low (they are smaller than *r8c4,* which is 5).
It's simpler: if green is low, it can't be 3 and 4 ( because the equal sum line totals would be greater than 9 ) : so the thermo bulbs in boxes two and eight must be the 3-4 pair. This forces the thermo ends in boxes four and six to be an 8-9 pair and R5C5 has no fill. Therefore green is high. And, for once I beat Mark's time by over 10 minutes.
My time is usually between 100 and 150% of Marc's, so I was quite surprised to finish this one in 17:55. I'm not sure if Marc missed something obvious, or I got lucky to stumble into a pathway that cut through the thicket.
If Mark had asked where the dark green and red in row 4 was, he could have eliminated R1C6 as 9, and found yellow as 9. Alternately the roping in C3,4,5 where the 9 could be eliminated as a candidate for R1C6. Other than that a nice solve of a fairly complex puzzle. -It's not bifurcation as long as you don't write in the numbers (Mark Goodliffe)
I see it here @38:35; The 3s are col4 of box2 in those two cells (seen by a "34" on that thermo). If a 3 on that thermo in box1, there's no place for the "3 in box2," so it's a 4. That "4" makes a 36 across the way. That "36" if a 3 would take out both places for a 3 in box6 (same thing) so it's a 6 there (leading up to 6 then 7 in box2. That "6" can only appear in r1c4 in box2. Cool (I'm sure there's more). Great job
When u see mark have an hour time , ud be expecting a 2-4hr(some times a day or let's come back later) solve. I'm glad I discovered the green/blue line entry rather than tackle the thermos. Half-hour solve , would have been 20 min had I not made the mistake I made. There is one thing about his pen marking on the thermos that I'd rather see used(lower-upper bounds instead of full-fill ie 1-5 instead of 12345 but his works for him...even tho there was alot of thermo digits) but that might just be a software habit for him
The proof path was probably to look at box 8. If you made green low and purple high, then the c5 high digits would give 5 cells using just 678 and 9 in box 8, so green couldn't be low.
I used box 6 for the proof path. If purple is high, then r5c7 and r5c8 are low. Also, green (r6c7) is low, and r4c9 is low. Finally, one of the cells on the X has to be low. That is five cells for four low numbers.
R3C4 and R7C6 can't be 3. You'd have an 8/9 pair looking at yellow if you did. I thought that was the case for row in box 5, but it's not the case there.
@@ruckmanikrishnan4221 I'm trying to recollect my thinking. If it were 8, then the pairs would need to be 1/7 and 2/6, and 2/6 is impossible on a German Whispers line. Therefore, the minimum the 2 could be paired with would be 7 in a 2/7 pair. The 1/8 would just come along for the ride.
It seems like this was a happy mistake, perhaps, than a legitimate logical conclusion, though. The GW line doesn't go through the potential 2/6 pair, so the puzzle definitely had an ambiguity on the RS cells.
@@BlakeMcCringleberry 2-6 is impossible _on a German whisper line_ ... but a 1267 set wouldn't _have_ a 2-6 on a German whisper line, because the pair that are together on the equal sum line are on different sections of the whisper line.
12:31 for me - *sees video length* Holy cow. I think once you realize that the sum for the sum lines has to be a digit that is the result of two different combinations of two cells from the whisper lines that are of different parity, the only possible way being 1/8 and 2/7, the puzzle easily collapses. I noticed it right away.
@@jefffrank177I'm seeing a lot of fast times being reported for this puzzle. I think most are making the same mistake. It's a pity it ends up getting to the solution via an unwarranted, but easy to make, step.
I think you shortcutted something here - the summing to 8 was a possibility as well, could not be eliminated until a lot more work was done (as Mark demonstrated).
@@ruckmanikrishnan4221 because the difference of at least 5 on the german whispers line means a 6 can only pair with a 1, with a 6 and a 2 the difference is only 4.
@@galacticmechanic1 that's cool but if you put a 6 on the green line in box 5, the ones wouldn't see each other cause they would be in different boxes.
@@galacticmechanic1 the region sum line digits are not adjacent on the whisper line...so 2-6 works until much later when you prove that 9 is the sum. Initially 8 is a legitimate sum
Finished in 42:17 with nearly no help from the video; only a few minutes of Mark's solve, which more or less covered Goodliffing I had already figured out, were needed to spark my mind enough to prove the parity of the German Whisper line on my own and go from there.
At 32:10 as soon as the 6 is eliminated in cell 8 of box 5 then cell 6 box 5 can't be a 3 because you exceed the needed 8 or 9 total. This leaves a 1/2 pair.
It's a shame that the puzzle doesn't punish the mistaken (but coincidentally correct) early assumption that the sum lines must add to 9. I think a lot of the very fast times must have made that blunder haha
One thing to not is that there can be no 4 in green or purple. as that would put a 9 on the region sum line. But I think that summons up everything I saw that Mark did not notice.
30:17 for me, but I thought I was quite slow in places. A nicely constructed puzzle, with good use of geometry and the intersecting lines. The only colouring I had was for highs and lows on the whisper line at the start. I think you were missing the geometrical constraints, which went both ways along the thermos, creating useful triples/quads/quints. Other than that, you seemed to keep asking the wrong questions. @ 22:00 - You're stuck. R3C3 and R7C7 cannot be 3, because that would put 1 & 2 on the start of their thermos, and R3C4 and R7C6 see all of the first three thermo digits. This rules out 5 from the tips of those thermos. In R6, you've got a high on the X and you've already got three other highs, so the rest must be 5 or lower. This means the last high in box 5 must be in R4, completing the set of highs for the row, so R4C2 must be 45. This makes R3C3=4 with 23 and 12 on the thermo, giving a 123 triple in the box. It also makes R4C2=5. Because R7C7 cannot be 3, R6C8 cannot be 4, so it's 67, R6C9 is 34, and R5C9 is 789. This gives you a 789 triple in the box, so the X must be 46. Now R5C7/8 are 235, giving a 1235 quad in R5. This makes R5C2/3 46789, giving a 46789 quint in box 4, making R4C2=5 @ 23:11 - "Is that really right?" - No. If there's a 3 on the intersections, they must be 1368, but an 8 doesn't mandate a 3 to require a 6. It is sometimes tempting to think that because 3 on a whisper forces an 8 or 9, that the reverse is true, but it is of course false. @ 42:57 - "If this was a 6..." - that's the wrong question. If it were a 3, then you'd need two 2s in box 6. It therefore has to be 6, forcing R2C6=7, R1C6=89, giving a 789 triple in C6, and making R4C6=6. This makes yellow=9. @ 54:39 - "Come on, do something else" - You've just created 789 triples in columns 4 and 6, making R1C4=R4C6=6, making the equal sum 9.
I did not feel that he was stuck at any point - he was following logical paths that were the ones that occurred to him in real time in a real solve. I really liked his reminder at the end of the video that he (and Simon) solve live, and they do their best, and that is what we get.
36:41 finish. I had a horrible mistake, assuming that a 6 needed to be on the lines in box 5. I saw 1-2-6-7 with 8s, or 1-3-6-8 with 9s, but I missed the 1-2-7-8 with 9s. This caused a big rewind after a good 10-15 minutes of work, when column 6 broke. It took a bit more to find my mistaken assumption, and then I was back in business. Fun puzzle, but definitely caught me sleepwalking.
@11:32 (Mark's "look-ahead" possibly being confusing folks have said): I would look in box8 (there's a 6789 and an 89 already in there) If two more 6789s in col5 in there, that's a 6789 quad (taking 67 out of that thermo cell -- goings back down to two low digits in row6 of box4) And with a low digit on that "X" clue, you would need five digits from these "low." So , that's not a 1234 quad down column5 , they're 6789s. 123s and 678s ÷ 2 for the 89s? That's what I saw though (box8 not box2). Hope that helps . 😂
No, same deal down in box8 (with the quin). 56789 (including that "purple,"), that's a 56789 quintuple (again taking the "67" out of that thermo cell) going down to two "lows" in box4 not working. Same deal. "Box8" as mentioned above. Hope that helps. 😂 PS: Oh, I didn't know if you knew, Folks, but on an "X" (ten) clue, one side is "low" and the other side is "high," *always* . That's easier to see, Mark. Go with that (as I'm sure you will after a bit). 👍🏻😂
Very confused about the way he approached the puzzle. The answer is the way the sum line single cell interacts with the whisper line and 6 can not appear on the whisper as its means you need two 6’s in box 5!
I don't get the rules. It says the blue line must sum to the same digit in every box it visits. But there's 4 digits on the blue line in the central and only one in the others, making this rule impossible ?
Solved it in 65:56, which isn't quick but at least it's palindromic. I determined the polarity of the pink and green cells on the German whisper line by realizing the pink cells and the "89" in c4 were looking at the tip of the bottom left thermometer, and the green cells and the X-domino in r6 were looking at the bulb. If the pinks were high and greens low, the pinks and the 89 would eliminate 3 options for high values at the tip of the thermometer, so both cells of the tip in c4 can't be high (one must be at most 5). The same can be said for the greens and the X in r6: they would eliminate 3 low values from the bulb of the thermometer, so both cells of the bulb can't be low (one must be at least 5). That leaves the only possibility of "low, 5, 5, 5, high", which breaks the rule, so the pinks are low and the greens high.
I dont think at all what you did here is bifurcation. If a cell has only 2 ( or a low amount ) possible candidates then exploring both of them on the shortterm can reveal that one of them doesnt work. If both work then you just rewind to the spot where you didnt fill it in. Process of elimination is a completely logical approach and different from assuming you are right without proof.
Bifurcation isn't assuming you're right without proof, though. It's making a guess to see what happens and following it to a great depth. Mark does it in his head, so doesn't view it as bifurcation. I don't think it should make any difference whether you're performing a feat of memory, or entering digits into the grid. It's still bifurcation, if the chain of logic is long.
@@RichSmith77 I urge you to do most of the puzzles on CtC without doing bifurcation because i dont remember a single puzzle where they didnt need to think ahead a few steps ahead with a possibility in mind. Process of Elimination is practically encapsulates the entirety of sudoku. By your logic thinking 5 steps ahead in chess is also "cheating"
@@AngRyGohan Thinking ahead a few steps - I'm absolutely fine with that. It just depends how far ahead you think is acceptable. It's shades of grey, rather than being black or white. However, Mark will use his excellent memory to remember long chains of hypothecated digits which I could never match, as my memory isn't as good as his. So if I was trying to follow the same logical path in my solve, I would have to put the digits in the grid, with the full intention of using the undo button afterwards to rewind my hypothetical digits. Doing so shouldn't mean I'm bifurcating, but Mark isn't, when it relies on the same logic. I try to minimise the amount I bifurcate, but I'm nowhere near good enough to solve all CtC's puzzles without resorting to it from time to time. I'm never totally satisfied when I do, though. And I've watched enough of Mark's and Simon's solves, after I've bifurcated my way to a solution, to know there's almost always a more elegant solution path. My aim is always to improve, to get better at spotting those elegant solution paths, so I'll resist bifurcating for far longer than I used to, before I was introduced to CtC. I don't understand your chess comparison. It's a completely different situation. Of course you need to look ahead in chess, and the further you can look ahead, the better a chess player you will be. It's also important to make a distinction between solving hand crafted sudoku puzzles, as featured on CtC, and computer generated sudokus of the type typically found in newspapers. The latter, I'd say bifurcation is a perfectly acceptable tool to reach a solution. However, hand crafted puzzles of the quality featured on CtC will usually have a solution path that doesn't require bifurcation. I'll always at least look for that path before resorting to bifurcation in desperation, and as a form of admission of defeat.
@@dwebb2805 yes, you're right, i don't know what has happened that i thought i need to have 89 and excluded 3, i guess i was lucky... i could have had double 8 and the sum as 9.
I thought at first you were referring to the corners of the German Whisper rectangle. r3c4 and r7c6 couldn't be 3s because their neighbours do see each other in a row, and also an 89 labelled yellow cell.
WTF! Due to a failed thought within the first 5 minutes (6-1 is impossible since the next "pair" would be 7-2 which adds up to too much) it just took me 17 minutes.
Finished in 25:33. Though I did kind of stumble into the solution. I knew that the equal sums numbers had to be a combo of a high and low on the german whisper lines, but I forgot that the numbers weren't necessarily correct and accidentally assumed that the lows I had put in were lows and the highs were high. This lead to a situation which couldn't be valid, so I knew that my highs and lows on the german whisper line were reversed. This lead to a really quick solve because everything else followed pretty quickly from there. Fun puzzle, though!
When I say it's bifurcation, I don't mean it as a slight against the solver. Very far from it. It is a sign of a not so great puzzle though. In my noobish opinion.
Seems harsh on the puzzle. It might be that there's a very clever break-in that doesn't require bifurcation. If the solver resorts to bifurcating early, they may just be missing the more elegant logic.
@@TiagoMorbusSa I never said it was straightforward. 🙂 Mark has admitted himself that Simon is better than he is at spotting the super clever break-ins. Mark will bifurcate, albeit in his head, far more readily than Simon will. There were ways to get the high/low polarity of the German Whisper line in this puzzle without doing the complicated chain that Mark used. You can tell, even Mark wasn't thrilled about using the logic he found here. He even thought about looking for a simpler way, but ended up using the exact same logic in reverse. In short, this was an excellent puzzle that didn't require bifurcation. Mark chose to bifurcate because he couldn't find a more elegant break-in.
nah, whenever the solver has to go "if this was 8, then that would be 7 and that would rule out X and Y" then it's bifurcation. I know it's not TECHNICALLY bifurcation, but it's just as enjoyable to solve or to watch (i.e. not much)@@RichSmith77
Problem regarding bifurcation is that this channel professes to solve everything logically and not by bifurcation or guessing or whatever. So no point blaming the comments.
The main difference I think is that bifurcation is happy if it finds a solution. A proof by necessity take into account all possible paths, but once you have proved a property of the puzzle, you can use it without calling it bifurcation.
But what is bifurcation? Do you have to fill in digits in the grid, or does it count if you do it in your head? Take an example from this video: At one point he asks "what happens if this is a 6" and then do the thing in his head. I would call that bifurcation. He could just as well have put in the 6 in the grid, and everything that follows from that.
@@57thornsThat's one level of bifurcation, but I don't think that's what Simon or Mark means when they say they don't bifurcate. If you take a guess at a digit and follow the path it takes you down for the next 10 minutes, to see if it breaks or not, even if it doesn't break and leads to a solution, I think most solvers would rewind to the point they made the guess to see what happened if they guessed differently. That's part of proving there's a unique solution, but I'd still call that bifurcating. Following a guess for 10 minutes would be clear bifurcation for most people. Following a guess for 5 seconds wouldn't be. The problem is, there's no way to define a hard limit of how long, or how far down a chain, you can go before it becomes bifurcation. It's all shades of grey rather than black and white. Just being able to memorise long chains in your head shouldn't be what stops something becoming bifurcation though. It still means you may be missing a more elegant, shorter step. For example, as a few comments point out, there were simpler ways to get the high/low polarity on the German whisper. I would consider the complicated chain Mark found to be a dark shade of grey on the scale of what's bifurcation and what isn't.
![Seungmin "그렇게, 천천히, 우리(As we are)" | [Stray Kids : SKZ-PLAYER]](http://i.ytimg.com/vi/kAzmhLHePqU/mqdefault.jpg)
The only difference between bifurcation and “looking ahead” is the solver’s memory!
Keep up the good work Mark. 😊
I finished in 63 minutes. The brilliance of this puzzle is astounding! Figuring out that greens had to be high based on column 6 was incredible to discover. This was some incredible setting. I liked this very much. Great Puzzle!
Thank you Mark. This is the first time I have beaten you, and by nearly a quarter of an hour. I loved the puzzle. I haven't watched your solve, but now, reading some comments it seems that appreciating right at the start that the only possible total for the equal sums was 9 was the key to getting off to a decent start.
If purple is high then a tip of thermo on the row is 5 making its bulb 1 which forces the sum line in box five to at least 2, 3, 7, 8, making yellow a 10.
This was the way I got the polarity of the whispers line too.
This is the best way. My way was slightly more complex, but it was easy enough for me to grasp it quickly (and I have a much smaller neural mass storage unit than Mark). In short, if *purple* is high, you get 5 low digits in *box 4.*
I explained my logic steps in a separate comment.
33:04. Didn't take too long to figure out which on green line were high and which were low thanks to the thermo with bulb in box 8. Using colours for high and low helped greatly. Quite a bit of eliminating candidates as opposed to figuring out which specific digit. Which I loved because you had to eliminate one to eliminate another further away which then made another one solve. Loved the bouncing around which made it enjoyable.
Mark, what a riveting video and solve - absolutely loved it. Thank you! A few specifics: I am glad you said what you said about bifurcating. I suspect that commenters on this and other videos who mention or accuse you of bifurcating have not tried to solve the puzzle themselves in some cases, and have not had to work though the many possible pathways that such a complex puzzle presents in order to decide how to move forward. Your 'look aheads' always seem essential to me in gaining understanding of the implications of the rules and markings in the grid. Another thing: I so appreciate and love that you (and Simon) solve puzzles live and "cold" as it were - you have not seen it before, you are not giving us a best or most efficient pathway through a puzzle, but you are approaching it just as we do when we click on the link. Your best is fantastic, impressive, inspiring - thank you so much for bringing us a video (plus a Wordle, plus other things) every single day. What a privilege to watch your mind work.
Thanks
And again! You're a star!!
@@CrackingTheCryptic No. I just don’t like (any) systematic payments (patreon or similar) but I love your channel, so now and again I say “thank you”
Finished in 43:55 - not bad compared to the video length! Some fun and satisfying logic in there.
33:02 for me. For the first time ever Ive been faster then Mark by far. What a fun puzzle.
21 MInutes. (Fine- 21.03 minutes).
Mark's solve was a lot harder than it should have been- once you know the "blues" in box five are low, 6 can't be on the oranges in box five (as it can't be next to two 1's), which gives you the "yellows" as well.
Loved the puzzle.
About 52 minutes for me. Proud of this solve on a slightly more challenging one. Great sudoku! Very fun
I needed the prompt from Mark to consider what would happen if r5c46 were the high digits in the central box, and then saw how that forces one of the thermos to end with a 5 and therefore start with a 1, which breaks r46c5 as that also needs a 1, which sets the parity on the green and blue lines. From there it was a fairly attritional process to finish in 35 minutes. This definitely felt like Mark was missing a _lot_ of sudoku and not following through on deductions (particularly where the same logic applies in multiple places).
I think forcing a 5 on to the tip of a thermo in box 4/6 was the key step that he missed and I’m assuming how the puzzle was constructed.
I solved it from the clue Mark gave me that 3 on a whisper corner creates an 89 pair that looks at yellow. He used it to solve parity, but didn't use it once he had blue on the whisper.
1:31:56 - That was really nice.
A clunky solve by Mark, but a brilliant, fun puzzle as always from James Kopp. Thanks!
Edit: I'm talking nonsense, don't listen to me. Read my reply to see how I messed up, at least a few other people messed up in the same way though.
13:45 for me. Best "solve-time to video-time" ratio I've ever had, never to be repeated! Impressive that Mark managed to solve it in such a different way, Equal Sum lines were surely the intended break-in. Each pair in box 5 is one high + one low, and there's only one corner digit that can make that work twice in one box.
Why is 26 and 17 not a combination to sum up to 8?
@@ruckmanikrishnan4221 I knew I'd be brought back down to Earth somehow! You're absolutely correct, I excluded 2-6 because I was confused by the crossed lines, 2-6 wouldn't work on whispers but are fine on equal sums. I had a sneaking feeling I had done something wrong, thank you for highlighting it. At least I only wasted 13 minutes on a wrong solution, not a full hour.
@@MisterM240216:50 for me with the same oversight. and i felt so accomplished 😅
@@mcalphax Someone who can share my pain! I even thought it was Mark who got confused by the crossed lines, but really it was me...
It would be helpful to other people reading comments if you were to edit your original comment to mention that you had made an error. It is discouraging to me to read comments that mention an alleged better way through a puzzle, only to read replies where it is acknowledged that the better way was not correct (or not the only way). Thanks for acknowledging it in the replies - more helpful to also have it in your original comment.
27 minutes. I felt there was a pretty easy proof for the 4 9s on the equal sums line, I had those filled in during the first minute, I think that gave me the unexpected head start to get a rare better speed than the legand himself. I don't get that often, I'll enjoy it while it lasts.
What was your proof? Genuine question.
what was it? I only was able to get 8/9 penciled in those boxes until very near the end of the puzzle. I can't help but feel you might have made an unsupported conclusion, as I can't think of any way to prove it that early.
Nice puzzle. I almost didn’t attempt it when I saw Mark’s time. Anything over 40 minutes is usually too hard for me. Glad I did give it a go. It wasn’t too hard at all. Don’t understand why Mark took so long. Not like him to miss stuff; like that 2/3 pair in box 6 which sorted r3c7.
Oh my days! What a puzzle!
This puzzle really took ages to do! 😅 but it was very great. And an awesome solve as well, thanks Mark! 😆
That was a really enjoyable puzzle to solve. Very well built. Thanks for sharing it
Rules: 02:02
Let's Get Cracking: 03:09
What about this video's Top Tier Simarkisms?!
Goodliffing: 1x (04:00)
Cooking with Gas: 1x (56:05)
Phistomefel: 1x (04:21)
And how about this video's Simarkisms?!
Ah: 7x (11:16, 17:42, 21:51, 26:53, 33:33, 36:29, 53:09)
Proof: 5x (08:09, 11:26, 11:31, 13:35, 13:46)
In Fact: 5x (08:12, 31:47, 36:50, 37:22, 40:39)
What Does This Mean?: 4x (06:08, 44:49, 52:49, 54:58)
Goodness: 3x (29:04, 35:30, 46:40)
Sorry: 3x (05:37, 19:37, 35:41)
Clever: 3x (57:01, 57:04, 57:04)
Obviously: 3x (47:49, 50:39, 51:32)
Wow: 3x (50:59, 55:30, 58:06)
Bother: 1x (20:27)
Apologies: 1x (56:57)
Beautiful: 1x (32:28)
Brilliant: 1x (00:34)
Extraordinary: 1x (58:24)
By Sudoku: 1x (56:27)
Shenanigans: 1x (00:19)
Progress: 1x (54:19)
Symmetry: 1x (20:05)
Weird: 1x (41:22)
Most popular number(>9), digit and colour this video:
Seventy Eight (6 mentions)
One (114 mentions)
Green (39 mentions)
Antithesis Battles:
High (29) - Low (21)
Even (5) - Odd (0)
Higher (7) - Lower (1)
Outside (2) - Inside (0)
Row (18) - Column (15)
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!
The best way to figure out the polarity of the *German whisper line* was described in this section by *Mn0ty*
My logic was slightly more complex, but it was easy enough for me to grasp it quickly (and I have a much smaller neural mass storage unit than Mark).
If *purple* is high, you get too many low digits in *box 4:*
🔹By German whisper logic, the *green* cell (r4c3) is low
🔹By sudoku, *r5c2* and *r5c3* are low
🔹By thermo logic, *r6c1* and *r6c2* are also low (they are smaller than *r8c4,* which is 5).
It's simpler: if green is low, it can't be 3 and 4 ( because the equal sum line totals would be greater than 9 ) : so the thermo bulbs in boxes two and eight must be the 3-4 pair. This forces the thermo ends in boxes four and six to be an 8-9 pair and R5C5 has no fill. Therefore green is high.
And, for once I beat Mark's time by over 10 minutes.
My time is usually between 100 and 150% of Marc's, so I was quite surprised to finish this one in 17:55. I'm not sure if Marc missed something obvious, or I got lucky to stumble into a pathway that cut through the thicket.
If Mark had asked where the dark green and red in row 4 was, he could have eliminated R1C6 as 9, and found yellow as 9. Alternately the roping in C3,4,5 where the 9 could be eliminated as a candidate for R1C6.
Other than that a nice solve of a fairly complex puzzle.
-It's not bifurcation as long as you don't write in the numbers (Mark Goodliffe)
Very beautiful puzzle.
I see it here @38:35;
The 3s are col4 of box2 in those two cells (seen by a "34" on that thermo).
If a 3 on that thermo in box1, there's no place for the "3 in box2," so it's a 4.
That "4" makes a 36 across the way.
That "36" if a 3 would take out both places for a 3 in box6 (same thing) so it's a 6 there (leading up to 6 then 7 in box2.
That "6" can only appear in r1c4 in box2.
Cool (I'm sure there's more).
Great job
61 mins finally
That did it
I forget what else.
That did it though.
22:26 for me. Nice puzzle!
When u see mark have an hour time , ud be expecting a 2-4hr(some times a day or let's come back later) solve.
I'm glad I discovered the green/blue line entry rather than tackle the thermos. Half-hour solve , would have been 20 min had I not made the mistake I made.
There is one thing about his pen marking on the thermos that I'd rather see used(lower-upper bounds instead of full-fill ie 1-5 instead of 12345 but his works for him...even tho there was alot of thermo digits) but that might just be a software habit for him
17:24 for me. Nice puzzle!
The proof path was probably to look at box 8. If you made green low and purple high, then the c5 high digits would give 5 cells using just 678 and 9 in box 8, so green couldn't be low.
I used box 6 for the proof path. If purple is high, then r5c7 and r5c8 are low. Also, green (r6c7) is low, and r4c9 is low. Finally, one of the cells on the X has to be low. That is five cells for four low numbers.
@@markp7262same here! Far more easier than the complicated route Mark took!
Wait, double clicking on a thermo highlights all the cells that are the same distance away from the bulb on a thermo?!
I think it might be holding left click not double click, not sure though :)
I ve been doing it one by one !!!!
R3C4 and R7C6 can't be 3. You'd have an 8/9 pair looking at yellow if you did. I thought that was the case for row in box 5, but it's not the case there.
17:19 here. The equal sum lines seemed very obvious right away.
Why was it obvious? Aren't 8&9 options?
@@ruckmanikrishnan4221 I'm trying to recollect my thinking.
If it were 8, then the pairs would need to be 1/7 and 2/6, and 2/6 is impossible on a German Whispers line. Therefore, the minimum the 2 could be paired with would be 7 in a 2/7 pair. The 1/8 would just come along for the ride.
It seems like this was a happy mistake, perhaps, than a legitimate logical conclusion, though. The GW line doesn't go through the potential 2/6 pair, so the puzzle definitely had an ambiguity on the RS cells.
@@BlakeMcCringleberryI believe I made the same (probably incorrect) assumption
@@BlakeMcCringleberry 2-6 is impossible _on a German whisper line_ ... but a 1267 set wouldn't _have_ a 2-6 on a German whisper line, because the pair that are together on the equal sum line are on different sections of the whisper line.
39 minutes for me. Great puzzle
46:11 for me
nice puzzle
At 51:59 r5c6 could never have been a 3 due to the equal sum rule.
12:31 for me - *sees video length* Holy cow. I think once you realize that the sum for the sum lines has to be a digit that is the result of two different combinations of two cells from the whisper lines that are of different parity, the only possible way being 1/8 and 2/7, the puzzle easily collapses. I noticed it right away.
Why is 26 and 17 not a combination to sum up to 8?
@@ruckmanikrishnan4221 Because 26 can't be adjacent on a whisper line :)
@@TheMeanderingduck6 the adjacent blue digits are not adjacent on the green. You absolutey could have 17 and 26 as a possible fill in this puzzle.
@@jefffrank177I'm seeing a lot of fast times being reported for this puzzle. I think most are making the same mistake. It's a pity it ends up getting to the solution via an unwarranted, but easy to make, step.
I think you shortcutted something here - the summing to 8 was a possibility as well, could not be eliminated until a lot more work was done (as Mark demonstrated).
I got this in 25:29. It was pretty easy when I quickly realized the only possible total in the whispers/equal sum crossover line.
Why is 26 and 17 not a combination to sum up to 8?
@@ruckmanikrishnan4221 because the difference of at least 5 on the german whispers line means a 6 can only pair with a 1, with a 6 and a 2 the difference is only 4.
The digits which form pairs on the RSL are not adjacent on the GWL...
@@galacticmechanic1 that's cool but if you put a 6 on the green line in box 5, the ones wouldn't see each other cause they would be in different boxes.
@@galacticmechanic1 the region sum line digits are not adjacent on the whisper line...so 2-6 works until much later when you prove that 9 is the sum. Initially 8 is a legitimate sum
I liked how 3 could not be in box one along the thermo, it removes all options from row 3 c 4
Finished in 42:17 with nearly no help from the video; only a few minutes of Mark's solve, which more or less covered Goodliffing I had already figured out, were needed to spark my mind enough to prove the parity of the German Whisper line on my own and go from there.
I feel like in an alternate universe, Mark Goodliffe is a Bomb-Defusing Expert...!
24 mins for me. Thanks.
At 32:10 as soon as the 6 is eliminated in cell 8 of box 5 then cell 6 box 5 can't be a 3 because you exceed the needed 8 or 9 total. This leaves a 1/2 pair.
Yep. I wondered why Mark had taken quite so long; he missed this deduction for about 20 minutes. Ouch!
It's a shame that the puzzle doesn't punish the mistaken (but coincidentally correct) early assumption that the sum lines must add to 9. I think a lot of the very fast times must have made that blunder haha
21:55 solve time here. Dang, I'm good
00:14:28, i guess i was lucky with initial break-in, but puzzle felt very approachable.
One thing to not is that there can be no 4 in green or purple. as that would put a 9 on the region sum line. But I think that summons up everything I saw that Mark did not notice.
30:17 for me, but I thought I was quite slow in places. A nicely constructed puzzle, with good use of geometry and the intersecting lines. The only colouring I had was for highs and lows on the whisper line at the start. I think you were missing the geometrical constraints, which went both ways along the thermos, creating useful triples/quads/quints. Other than that, you seemed to keep asking the wrong questions.
@ 22:00 - You're stuck. R3C3 and R7C7 cannot be 3, because that would put 1 & 2 on the start of their thermos, and R3C4 and R7C6 see all of the first three thermo digits. This rules out 5 from the tips of those thermos. In R6, you've got a high on the X and you've already got three other highs, so the rest must be 5 or lower. This means the last high in box 5 must be in R4, completing the set of highs for the row, so R4C2 must be 45. This makes R3C3=4 with 23 and 12 on the thermo, giving a 123 triple in the box. It also makes R4C2=5. Because R7C7 cannot be 3, R6C8 cannot be 4, so it's 67, R6C9 is 34, and R5C9 is 789. This gives you a 789 triple in the box, so the X must be 46. Now R5C7/8 are 235, giving a 1235 quad in R5. This makes R5C2/3 46789, giving a 46789 quint in box 4, making R4C2=5
@ 23:11 - "Is that really right?" - No. If there's a 3 on the intersections, they must be 1368, but an 8 doesn't mandate a 3 to require a 6. It is sometimes tempting to think that because 3 on a whisper forces an 8 or 9, that the reverse is true, but it is of course false.
@ 42:57 - "If this was a 6..." - that's the wrong question. If it were a 3, then you'd need two 2s in box 6. It therefore has to be 6, forcing R2C6=7, R1C6=89, giving a 789 triple in C6, and making R4C6=6. This makes yellow=9.
@ 54:39 - "Come on, do something else" - You've just created 789 triples in columns 4 and 6, making R1C4=R4C6=6, making the equal sum 9.
I did not feel that he was stuck at any point - he was following logical paths that were the ones that occurred to him in real time in a real solve. I really liked his reminder at the end of the video that he (and Simon) solve live, and they do their best, and that is what we get.
36:41 finish. I had a horrible mistake, assuming that a 6 needed to be on the lines in box 5. I saw 1-2-6-7 with 8s, or 1-3-6-8 with 9s, but I missed the 1-2-7-8 with 9s. This caused a big rewind after a good 10-15 minutes of work, when column 6 broke. It took a bit more to find my mistaken assumption, and then I was back in business. Fun puzzle, but definitely caught me sleepwalking.
@11:32 (Mark's "look-ahead" possibly being confusing folks have said):
I would look in box8 (there's a 6789 and an 89 already in there)
If two more 6789s in col5 in there, that's a 6789 quad (taking 67 out of that thermo cell -- goings back down to two low digits in row6 of box4)
And with a low digit on that "X" clue, you would need five digits from these "low."
So , that's not a 1234 quad down column5 , they're 6789s.
123s and 678s ÷ 2 for the 89s?
That's what I saw though (box8 not box2).
Hope that helps . 😂
Oh, 56789.
Go to it, Mark. 😂
No, same deal down in box8 (with the quin).
56789 (including that "purple,"), that's a 56789 quintuple (again taking the "67" out of that thermo cell) going down to two "lows" in box4 not working.
Same deal.
"Box8" as mentioned above.
Hope that helps. 😂
PS: Oh, I didn't know if you knew, Folks, but on an "X" (ten) clue, one side is "low" and the other side is "high," *always* .
That's easier to see, Mark.
Go with that (as I'm sure you will after a bit). 👍🏻😂
Solved in 30:29.
Very confused about the way he approached the puzzle. The answer is the way the sum line single cell interacts with the whisper line and 6 can not appear on the whisper as its means you need two 6’s in box 5!
I don't get the rules. It says the blue line must sum to the same digit in every box it visits. But there's 4 digits on the blue line in the central and only one in the others, making this rule impossible ?
See "for each visit" in the rules. The two blue line segments in the central box are counted separately
Solved it in 65:56, which isn't quick but at least it's palindromic.
I determined the polarity of the pink and green cells on the German whisper line by realizing the pink cells and the "89" in c4 were looking at the tip of the bottom left thermometer, and the green cells and the X-domino in r6 were looking at the bulb. If the pinks were high and greens low, the pinks and the 89 would eliminate 3 options for high values at the tip of the thermometer, so both cells of the tip in c4 can't be high (one must be at most 5). The same can be said for the greens and the X in r6: they would eliminate 3 low values from the bulb of the thermometer, so both cells of the bulb can't be low (one must be at least 5). That leaves the only possibility of "low, 5, 5, 5, high", which breaks the rule, so the pinks are low and the greens high.
I dont think at all what you did here is bifurcation. If a cell has only 2 ( or a low amount ) possible candidates then exploring both of them on the shortterm can reveal that one of them doesnt work. If both work then you just rewind to the spot where you didnt fill it in. Process of elimination is a completely logical approach and different from assuming you are right without proof.
Bifurcation isn't assuming you're right without proof, though. It's making a guess to see what happens and following it to a great depth. Mark does it in his head, so doesn't view it as bifurcation. I don't think it should make any difference whether you're performing a feat of memory, or entering digits into the grid. It's still bifurcation, if the chain of logic is long.
@@RichSmith77 I urge you to do most of the puzzles on CtC without doing bifurcation because i dont remember a single puzzle where they didnt need to think ahead a few steps ahead with a possibility in mind. Process of Elimination is practically encapsulates the entirety of sudoku.
By your logic thinking 5 steps ahead in chess is also "cheating"
@@AngRyGohan Thinking ahead a few steps - I'm absolutely fine with that. It just depends how far ahead you think is acceptable. It's shades of grey, rather than being black or white. However, Mark will use his excellent memory to remember long chains of hypothecated digits which I could never match, as my memory isn't as good as his. So if I was trying to follow the same logical path in my solve, I would have to put the digits in the grid, with the full intention of using the undo button afterwards to rewind my hypothetical digits. Doing so shouldn't mean I'm bifurcating, but Mark isn't, when it relies on the same logic.
I try to minimise the amount I bifurcate, but I'm nowhere near good enough to solve all CtC's puzzles without resorting to it from time to time. I'm never totally satisfied when I do, though. And I've watched enough of Mark's and Simon's solves, after I've bifurcated my way to a solution, to know there's almost always a more elegant solution path. My aim is always to improve, to get better at spotting those elegant solution paths, so I'll resist bifurcating for far longer than I used to, before I was introduced to CtC.
I don't understand your chess comparison. It's a completely different situation. Of course you need to look ahead in chess, and the further you can look ahead, the better a chess player you will be.
It's also important to make a distinction between solving hand crafted sudoku puzzles, as featured on CtC, and computer generated sudokus of the type typically found in newspapers. The latter, I'd say bifurcation is a perfectly acceptable tool to reach a solution. However, hand crafted puzzles of the quality featured on CtC will usually have a solution path that doesn't require bifurcation. I'll always at least look for that path before resorting to bifurcation in desperation, and as a form of admission of defeat.
This is an excellent reply. Thanks for taking the time to share your thoughts.@@RichSmith77
you cant have 3 on a green line here, that will force 8,9 on the sides and that will clash with the 89 sum on the blue line.
when the cells aren't in the same row/col/box they can be the same digit, so i don't understand your point?
@@dwebb2805 yes, you're right, i don't know what has happened that i thought i need to have 89 and excluded 3, i guess i was lucky... i could have had double 8 and the sum as 9.
I thought at first you were referring to the corners of the German Whisper rectangle. r3c4 and r7c6 couldn't be 3s because their neighbours do see each other in a row, and also an 89 labelled yellow cell.
Might have gone a little quicker if he spotted the roping on the centre cross
29:33 for me. nice and slow.
27:57 for me. i renbanember solving this
WTF!
Due to a failed thought within the first 5 minutes (6-1 is impossible since the next "pair" would be 7-2 which adds up to too much) it just took me 17 minutes.
Finished in 25:33. Though I did kind of stumble into the solution. I knew that the equal sums numbers had to be a combo of a high and low on the german whisper lines, but I forgot that the numbers weren't necessarily correct and accidentally assumed that the lows I had put in were lows and the highs were high. This lead to a situation which couldn't be valid, so I knew that my highs and lows on the german whisper line were reversed. This lead to a really quick solve because everything else followed pretty quickly from there.
Fun puzzle, though!
Spotted quite a few missed straight forward deductions watching this. Not Marks greatest solve..
Please do share.
28:00 fod me
When I say it's bifurcation, I don't mean it as a slight against the solver. Very far from it.
It is a sign of a not so great puzzle though. In my noobish opinion.
Seems harsh on the puzzle. It might be that there's a very clever break-in that doesn't require bifurcation. If the solver resorts to bifurcating early, they may just be missing the more elegant logic.
except the "it might be" is a wild dream@@RichSmith77
if a world class puzzle solver can't see the straightforward solution, what hope do I have?
@@TiagoMorbusSa I never said it was straightforward. 🙂
Mark has admitted himself that Simon is better than he is at spotting the super clever break-ins. Mark will bifurcate, albeit in his head, far more readily than Simon will.
There were ways to get the high/low polarity of the German Whisper line in this puzzle without doing the complicated chain that Mark used. You can tell, even Mark wasn't thrilled about using the logic he found here. He even thought about looking for a simpler way, but ended up using the exact same logic in reverse.
In short, this was an excellent puzzle that didn't require bifurcation. Mark chose to bifurcate because he couldn't find a more elegant break-in.
nah, whenever the solver has to go "if this was 8, then that would be 7 and that would rule out X and Y" then it's bifurcation. I know it's not TECHNICALLY bifurcation, but it's just as enjoyable to solve or to watch (i.e. not much)@@RichSmith77
I solved it about 25 minutes, what Mark was doing I don't understand.
Problem regarding bifurcation is that this channel professes to solve everything logically and not by bifurcation or guessing or whatever. So no point blaming the comments.
The main difference I think is that bifurcation is happy if it finds a solution.
A proof by necessity take into account all possible paths, but once you have proved a property of the puzzle, you can use it without calling it bifurcation.
But what is bifurcation? Do you have to fill in digits in the grid, or does it count if you do it in your head? Take an example from this video: At one point he asks "what happens if this is a 6" and then do the thing in his head. I would call that bifurcation. He could just as well have put in the 6 in the grid, and everything that follows from that.
@@57thornsThat's one level of bifurcation, but I don't think that's what Simon or Mark means when they say they don't bifurcate. If you take a guess at a digit and follow the path it takes you down for the next 10 minutes, to see if it breaks or not, even if it doesn't break and leads to a solution, I think most solvers would rewind to the point they made the guess to see what happened if they guessed differently. That's part of proving there's a unique solution, but I'd still call that bifurcating.
Following a guess for 10 minutes would be clear bifurcation for most people. Following a guess for 5 seconds wouldn't be. The problem is, there's no way to define a hard limit of how long, or how far down a chain, you can go before it becomes bifurcation. It's all shades of grey rather than black and white.
Just being able to memorise long chains in your head shouldn't be what stops something becoming bifurcation though. It still means you may be missing a more elegant, shorter step.
For example, as a few comments point out, there were simpler ways to get the high/low polarity on the German whisper. I would consider the complicated chain Mark found to be a dark shade of grey on the scale of what's bifurcation and what isn't.
Solved in 40:40.