"Any solve of a sudoku is a valid tick in your mental health box." Yes, I agree, Mark. This was a very fun puzzle and video. I did the methodical approach, too, and got over the final bit by coloring 1s and 2s - a technique I learned from you, of course. Thanks, as always, for doing what you do to bring us so much sudoku fun!
Good practice for spotting y-wings. There are at least 4 of them using the cages, and spotting all 4 leaves all the cages completed other than a 12 pair in r1. Explains the puzzle's name, too.
Silly me! I observed there were 25 caged cells, but there can only be 27 instances of friendliness, so at most 2 of the caged numbers can be doubly friendly (for instance a 1 in R2C1 would be doubly friendly, being both in box 1 and column 1). This does give some deductions, for instance R2C1 can't be 1 because R4C1 would be 4 and R7C1 would be 7, making for 3 doubly friendly digits. But it peters out quickly so you have to go back to plain old Sudoku. You eventually end up with only one caged doubly friendly digit, the 7 in R7C1 (box 7). You also get an uncaged (singly) friendly digit: the 1 at R3C2 is in box 1.
Yes, when I had most of the digits placed in the friendly cages, I noticed that 1 was missing in box 1. Started over a few times to check if I made an error... Frustrating.
14:36, felt like I was making a mistake pencil marking all the boxes, the break in required a few steps of logic that I wouldn't have been able to make a couple of years ago.
My break in was a bit different. You can only have a maximum of 27 friendly digits in a puzzle (one for each row, column, and box), and there are 25 cages. This means there can only be a maximum of two cages that are friendly in more than one regard, because those basically take up two friendly possibilities. If r2c4 was a 2, it would take up row and box 2, r2c1 would be a 1 in column and box 1, and r4c1 would be a 4 in row and box 4. So, r2c4 is a 4.
I found the first break-in (spoiler below) and then had to find a second one later on. Good fun. Thank you. ........ . . . . . . . . . . . Row 3 and 7. Cols 1 and 7. Don't know what it is called. A simple logic loop basically.
Definitely needed a little help with the break in strategy but managed a 26 minute or so clear! Happy with that in the end. Mark and Simon’s prowess with how everything relates in the grid is always sublime to watch.
Need to remind myself to never ever do puzzles with a friendly digits. One misplaced digit makes a relatively easy puzzle into a really hard one. And it's for the second time of two friendly digit puzzle I tried.
Love to see this puzzle solved again with a Y wing technique brush up lesson for the less advanced solvers like myself. Mark Vs puzzle, Mark always wins !
I had to restart two times. First time I misread the roles. I added indexing of the position inside the box 🤦♀️. Second time I typed the wrong digits. But the third time was a charm and managed to finish in 19:02
Ended up finishing at 56 minutes and change. After two failed attempts (I failed to properly mark every box at the beginning, leading to some very drawn-out dead ends), I just rewound to the very beginning but kept my timer running. Then I did it mostly like Mark did up to 9:17 when I got stuck again for a while. I'm terrible at spotting y-wings. Once the 5 revealed itself, it was slow and methodical until the finish. I didn't want to rewind a fourth time, but I'm also not racing, so slow and steady is fine. But I enjoyed the puzzle.
is the "Why not ?" title a reference to Y-wings ? Took me more than 30 minutes on this one even if I got the break in quite quickly. Guess I'm quite bad at finding the weak points, got a few pairs to carry around. Always amaze me how fast Mark is on "classic solve" (after the break in)
A nice bit of logic here, and a fairly quick solve once you notice the patterns. My time today was 15:05, solver number 8887. (If only I'd been one solver later!)
Anyone have tips for avoiding mistakes? My biggest problem with the more complex puzzles is not noticing all possibilities that need to be eliminated before trusting a bit of logic.
What helped me a lot in the beginning is activating the 'conflict checker' in the software (cogwheel -> gameplay -> check pencilmarks 'on') I don't use it anymore, but relied on it for quite some time, especially in the more complex puzzles where my brain would do a 'simon' and only focus on the complex logic, instead of the 'easy' elimination of pencil marks
I wish I had a good answer. I'm prone to making silly mistakes. One puzzle can require hundreds of deductions, so even if I'm 99% accurate, that still means quite a few puzzles go awry. The best advice I have is to study your mistakes. After I mess up, I always go back and try to understand where I went wrong. Over time I've gotten better at avoiding mistakes and developing an instinct for when I should double-check my logic. Most puzzles now have the option to check your progress. You can click the solution checker and it will tell you if all the digits you entered so far are correct. This has been a life saver for me! Nothing is more frustrating than filling out 75% of the puzzle only to find out I made a small mistake half an hour ago.
I commonly use a supposition marker. I will put a color flag on something when I am going to test a supposition, and then proceed to fill in digits. I consider making a second supposition when the first remains unresolved between true or false to be bifurcation. As such I am often trying to select suppositions that will fail rather quickly. For example in this puzzle I saw that 6 in column 5 is quite restricted and placing a 6 in that column within box 2 would affect many cells across the entire grid. That was my first test item and during that test I gained a better understanding of how some of the clue cells interact with each other. Using the undo (CTRL+Z) button at the end of a test easily backs things up to the marker.
I solved rather quickly, then I came here to see what amazing break in I was missing and it turned out I had followed the right path. On one hand I am glad, on the other I was hoping to learn some amazing trick. Fun puzzle though.
16m29s for me - I am yet to not be surprised by how powerful the Friendly Cell constraint is. Even here, where it just marked some of the Friendly Cells gave access to a bunch of Y-Wings.
37:10@#4960. The concept behind the solve path was clear, but actually finding the eliminations took a long time. Eventually I found enough of them to break the rest of it open. Incidentally, has anyone else been having trouble with the web app recently? For some reason my control key keeps sticking in place, or not engaging/disengaging when it should, and I have to fight it to register the marks I actually want to enter. It's quite annoying, and slows me down considerably. I thought it might be my keyboard for a bit, but it happens with both control keys.
My logic here was the importance of the word OR in the rules... for example r1c2 could NOT be a one without being in box AND column 1. That allows you to fill in a lot of cages forcing a quick solve. Completed in 8m06s.
OR does not exclude AND though. In Boolean logic, if A AND B is true, then A OR B must also be true. The Boolean operator XOR (Exclusive OR) is what you describe (i.e. exactly 1 and only 1 of A or B must be true). If that was intended, the rules should have been written with "match exactly one of the rows, boxes or columns of the cell"
Rules: 01:43 And how about this video's Simarkisms?! Clever: 5x (03:26, 07:27, 11:58, 12:02, 14:51) Approachable: 2x (03:03, 14:39) Ah: 2x (05:21, 10:23) Goodness: 1x (11:56) The Answer is: 1x (04:14) Lovely: 1x (09:17) Hang On: 1x (06:06) In Fact: 1x (10:26) Pencil Mark/mark: 1x (06:45) Most popular digit this video: One (43 mentions) Antithesis Battles: Column (18) - Row (13) 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!
You must think that I thrive on pointing out errors. It's not true. I love your face. I love your voice. I love feeling, empathizing, sympathizing or what not, with your frustration when can't find something and feeling your accomplishment, the satisfaction that can only be found in finding the solve. And I love the journey, and I wouldn't even take the journey without your company. And the "you" here is inclusive for the other channel host (side note: the banter between you two is a different pleasure). I'm not even going to mention anything about the chapters. They are definitely not affecting my OCD.
13:29 without any Y-wings or advanced tricks, just pencil marking and lots of pairs eliminating digits from other cages. The comments have me wondering if I did something wrong and got lucky...
New low for me: a 15-minute video including introduction and all, and I completely failed it. I had 7s pencil-marked in the two cages in row 4, box 6, columns 8/9, for reasons only known to my useless head, and that kills it all... -.-
"Any solve of a sudoku is a valid tick in your mental health box." Yes, I agree, Mark. This was a very fun puzzle and video. I did the methodical approach, too, and got over the final bit by coloring 1s and 2s - a technique I learned from you, of course. Thanks, as always, for doing what you do to bring us so much sudoku fun!
Good practice for spotting y-wings. There are at least 4 of them using the cages, and spotting all 4 leaves all the cages completed other than a 12 pair in r1. Explains the puzzle's name, too.
exactly how I did it!
26:38 for me. It took me a while to spot the break in. Btw Mark’s ability to solve normal sudoku is just stunning :)
As a native german speaker, i loved when you said: "Nein, i don't." At around 11:30 or such.
Silly me! I observed there were 25 caged cells, but there can only be 27 instances of friendliness, so at most 2 of the caged numbers can be doubly friendly (for instance a 1 in R2C1 would be doubly friendly, being both in box 1 and column 1).
This does give some deductions, for instance R2C1 can't be 1 because R4C1 would be 4 and R7C1 would be 7, making for 3 doubly friendly digits.
But it peters out quickly so you have to go back to plain old Sudoku.
You eventually end up with only one caged doubly friendly digit, the 7 in R7C1 (box 7). You also get an uncaged (singly) friendly digit: the 1 at R3C2 is in box 1.
Yes, when I had most of the digits placed in the friendly cages, I noticed that 1 was missing in box 1. Started over a few times to check if I made an error... Frustrating.
Finished in 11:41. I spotted like two Y-wings and followed two, maybe three long chains until they broke.
solved in 9:23 - high frequency of Y-wings here, which I am ironically not very good at spotting relative to other deductions
I spotted the breakins and was very pleased with myself for noticing them. Finished in 13:26. And now I finally understand what Y wings are!
11:29! loved it despite my distaste for y-wings!
Finished in 11:36. That was a nice way to break in!
14:36, felt like I was making a mistake pencil marking all the boxes, the break in required a few steps of logic that I wouldn't have been able to make a couple of years ago.
My break in was a bit different. You can only have a maximum of 27 friendly digits in a puzzle (one for each row, column, and box), and there are 25 cages. This means there can only be a maximum of two cages that are friendly in more than one regard, because those basically take up two friendly possibilities. If r2c4 was a 2, it would take up row and box 2, r2c1 would be a 1 in column and box 1, and r4c1 would be a 4 in row and box 4. So, r2c4 is a 4.
Great logic :)
@4:04 Oh, the pencil marks here. That's very satisfying in an OCD way.
Pretty sure the bent triple at R2C1/R2C4/R4C1 fixing R4C4 was the intended break in, but it got there. Fun little Bent Triple/Y-Wing puzzle.
Yes, exactly.
My (maybe easier) break in was R2C4. If it is 4 then R6C4 = 6, if it is 2 then R2C6 = 6. So R4C6 cannot be 6 => R6C4 = 6
My break in was r7c7 which can’t be a 7 or it breaks col 1
I think there are several possible breakins, all of the same "type".
The first non-gas sudoku I’ve completed from you guys. I am truly thankful.
I found the first break-in (spoiler below) and then had to find a second one later on. Good fun. Thank you. ........
.
.
.
.
.
.
.
.
.
.
. Row 3 and 7. Cols 1 and 7. Don't know what it is called. A simple logic loop basically.
Definitely needed a little help with the break in strategy but managed a 26 minute or so clear! Happy with that in the end. Mark and Simon’s prowess with how everything relates in the grid is always sublime to watch.
Need to remind myself to never ever do puzzles with a friendly digits. One misplaced digit makes a relatively easy puzzle into a really hard one. And it's for the second time of two friendly digit puzzle I tried.
Fun puzzle. I also really enjoyed Mark’s solve.
I love watching Mark solve classic sudoku quickly, it's really impressive
Love to see this puzzle solved again with a Y wing technique brush up lesson for the less advanced solvers like myself.
Mark Vs puzzle, Mark always wins !
I had to restart two times.
First time I misread the roles. I added indexing of the position inside the box 🤦♀️. Second time I typed the wrong digits. But the third time was a charm and managed to finish in 19:02
Ended up finishing at 56 minutes and change. After two failed attempts (I failed to properly mark every box at the beginning, leading to some very drawn-out dead ends), I just rewound to the very beginning but kept my timer running. Then I did it mostly like Mark did up to 9:17 when I got stuck again for a while. I'm terrible at spotting y-wings. Once the 5 revealed itself, it was slow and methodical until the finish. I didn't want to rewind a fourth time, but I'm also not racing, so slow and steady is fine. But I enjoyed the puzzle.
Finished in 14:01. Man, it's been so long since I've done normal sudokus, I forgot how to do Y-wings :p.... Fortunately, the logic still works :D....
is the "Why not ?" title a reference to Y-wings ?
Took me more than 30 minutes on this one even if I got the break in quite quickly. Guess I'm quite bad at finding the weak points, got a few pairs to carry around.
Always amaze me how fast Mark is on "classic solve" (after the break in)
managed this in 11:40, was a cute concept that i'd like to see more of
A nice bit of logic here, and a fairly quick solve once you notice the patterns. My time today was 15:05, solver number 8887. (If only I'd been one solver later!)
Took me 8 years to spot the break in - after that it was pretty smooth ...nice puzzle
Quite impressive, I gave up after half of an hour.
7:55 for me. Nice puzzle!
14:34 for me. you just have to spot 2 or 3 things at the start. otherwise it is just a classic sudoku.
Anyone have tips for avoiding mistakes? My biggest problem with the more complex puzzles is not noticing all possibilities that need to be eliminated before trusting a bit of logic.
What helped me a lot in the beginning is activating the 'conflict checker' in the software (cogwheel -> gameplay -> check pencilmarks 'on') I don't use it anymore, but relied on it for quite some time, especially in the more complex puzzles where my brain would do a 'simon' and only focus on the complex logic, instead of the 'easy' elimination of pencil marks
I wish I had a good answer. I'm prone to making silly mistakes. One puzzle can require hundreds of deductions, so even if I'm 99% accurate, that still means quite a few puzzles go awry.
The best advice I have is to study your mistakes. After I mess up, I always go back and try to understand where I went wrong. Over time I've gotten better at avoiding mistakes and developing an instinct for when I should double-check my logic.
Most puzzles now have the option to check your progress. You can click the solution checker and it will tell you if all the digits you entered so far are correct. This has been a life saver for me! Nothing is more frustrating than filling out 75% of the puzzle only to find out I made a small mistake half an hour ago.
@@11mandylion I had no idea there was a conflict checker in the software, I'll have to play with that! Thanks
I commonly use a supposition marker. I will put a color flag on something when I am going to test a supposition, and then proceed to fill in digits. I consider making a second supposition when the first remains unresolved between true or false to be bifurcation. As such I am often trying to select suppositions that will fail rather quickly. For example in this puzzle I saw that 6 in column 5 is quite restricted and placing a 6 in that column within box 2 would affect many cells across the entire grid. That was my first test item and during that test I gained a better understanding of how some of the clue cells interact with each other. Using the undo (CTRL+Z) button at the end of a test easily backs things up to the marker.
I solved rather quickly, then I came here to see what amazing break in I was missing and it turned out I had followed the right path. On one hand I am glad, on the other I was hoping to learn some amazing trick. Fun puzzle though.
16m29s for me - I am yet to not be surprised by how powerful the Friendly Cell constraint is. Even here, where it just marked some of the Friendly Cells gave access to a bunch of Y-Wings.
34:50 for me...some sneaky tricks to find
Nice puzzle and quickly done.
37:10@#4960. The concept behind the solve path was clear, but actually finding the eliminations took a long time. Eventually I found enough of them to break the rest of it open.
Incidentally, has anyone else been having trouble with the web app recently? For some reason my control key keeps sticking in place, or not engaging/disengaging when it should, and I have to fight it to register the marks I actually want to enter. It's quite annoying, and slows me down considerably. I thought it might be my keyboard for a bit, but it happens with both control keys.
11:20 for me. Nice puzzle!
I think the clue was in the name Mark, it's a much more elegant break in if you notice that.
12:55 for me. That was fun and quick.
My logic here was the importance of the word OR in the rules... for example r1c2 could NOT be a one without being in box AND column 1. That allows you to fill in a lot of cages forcing a quick solve. Completed in 8m06s.
OR does not exclude AND though. In Boolean logic, if A AND B is true, then A OR B must also be true. The Boolean operator XOR (Exclusive OR) is what you describe (i.e. exactly 1 and only 1 of A or B must be true). If that was intended, the rules should have been written with "match exactly one of the rows, boxes or columns of the cell"
Also, with your interpretation of OR, the puzzle doesn't have a valid solution. There's a 7 in r7c1 that's in row 7 AND box 7.
12:55 for me. This was a very enjoyable GAS!
10:40 for me. I solved this on institute, its hard to remember the exact time.
Rules: 01:43
And how about this video's Simarkisms?!
Clever: 5x (03:26, 07:27, 11:58, 12:02, 14:51)
Approachable: 2x (03:03, 14:39)
Ah: 2x (05:21, 10:23)
Goodness: 1x (11:56)
The Answer is: 1x (04:14)
Lovely: 1x (09:17)
Hang On: 1x (06:06)
In Fact: 1x (10:26)
Pencil Mark/mark: 1x (06:45)
Most popular digit this video:
One (43 mentions)
Antithesis Battles:
Column (18) - Row (13)
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!
Nicely done.
Brilliant puzzle!
You must think that I thrive on pointing out errors. It's not true. I love your face. I love your voice. I love feeling, empathizing, sympathizing or what not, with your frustration when can't find something and feeling your accomplishment, the satisfaction that can only be found in finding the solve. And I love the journey, and I wouldn't even take the journey without your company. And the "you" here is inclusive for the other channel host (side note: the banter between you two is a different pleasure). I'm not even going to mention anything about the chapters. They are definitely not affecting my OCD.
You really should turn on conflict checker!
Took me soooo long to figure out what a y-wing was but once I got it 00:25:07
Why not? = Y not?
Realizing this was my break-in. I had to teach myself how to do them; I'm bad at spotting them.
35:38 for me
nice puzzle
13:29 without any Y-wings or advanced tricks, just pencil marking and lots of pairs eliminating digits from other cages. The comments have me wondering if I did something wrong and got lucky...
Got a bit stuck until I realized I missed some Sudoku... 19:05 for me
I am pretty sure that Why Not a play on Y Knot?
A lot of sudoku in this sudoku
24:45 for me.
I solved it
21:09 for me
New low for me: a 15-minute video including introduction and all, and I completely failed it. I had 7s pencil-marked in the two cages in row 4, box 6, columns 8/9, for reasons only known to my useless head, and that kills it all... -.-
14:01 for me
Nice one! 23:11 for me. (#6575)
19 minutes
16:50 for me