Thankyou very much Mark for this unexpected feature! The idea for this constraint was Sujoyku's, and he asked me if I wanted to collab on it because it is basically a mash-up of my two favourite constraints that I've come up with - counting circles and same / different difference lines. Of course I said yes straight away and it was a huge pleasure working with him on it. He first set a 6x6 which I thought was great, and I suggested it would be nice to make this into a 3-parter, with a nice introductory 4x4 and a more meaty 9x9 where some other different implications and silliness can be explored. He set the 4x4 too which I thought served as a perfect part 1 - as Mark said, it is surprisingly not-trivial - I think the difficulty was judged perfectly there. I made the 9x9, and from the start I knew I wanted a square with differences of 4, and a long stupid line which ends up getting 1 and 9 forced next to each other on it to make for a fun little moment. Forcing that 1-9 in a natural way was the biggest challenge of setting this, but overall it was quite a smooth and quick one to set. Great invention by Sujoyku and I think the constraint has legs to be combined with other rulsesets. This is something we may explore more after Christmas :) Also thankyou to Juggler for the very kind recommendation!
I was impressed by the gentle ways that we were introduced to this wonderful new rule! Congratulations Marty and Sujoyku on another brilliant puzzle! And thanks to Mark for featuring it, and Juggler for recommending it! 🙂
Thank you for this wonderful feature, Mark! I loved how you found out about the parity changes along the length-5-difference lines and put it too good use immediately. It was also very nice to see you acknowledging the impossibility of difference 0. (Fun fact: This observation can already be used as a deduction in the 4x4 intro puzzle.) Thank you so much for your incredibly kind words in the end! Last but not least, I want to give a big shoutout to Marty Sears. As you probably all know his rat run series, I do not have to tell you what a fantastic setter he is. But he is also one of the most kind and helpful people I know and it was a true pleasure to work with him. Thank you for this fun collaboration and for all your support, Marty!
It's completely terrible wording. You can have a difference of 0, and that would be the only way to have a 5 long line, because between two same digits is no difference. The solution here is complete garbage with a difference of 1 then three pairs with 3. The description is totally misleading
@@JP-yu1qc Regardless of whether you are right or wrong in your comment (and in this case you are totally wrong), using that tone to address someone on this channel, especially a setter, is utterly rude.
If Mark uses a different interpretation of the rules than you, you can be sure that you have it wrong.. The polite thing to do in that case, is to suggest a better phrasing of the rules.
My joy has increased by 1) watching this video (which increases my joy daily, I will add); 2) enjoying your joy, Mark ... I have not tried the puzzles, but I think I will do so, having watched you solve these. I am always amazed at how readily your mind grasps the parity implications of some of the variant rules that you encounter. I really need to beef up my parity thinking, because I am sure it would help me solve sudoku puzzles faster - and probably with more joy! Thanks so much for this video.
For that 11 cell line in the last puzzle, you should have suspected it would be something ridiculous like eight 8s and two 2s as soon as you saw "Marty Sears." lol
I finished Part 1 in 10:30 minutes, Part 2 in 12:07 minutes, and Part 3 in 43:55 minutes for a total of 66:32 minutes. I was a little confused at first until Mark described it as being similar to the counting circles clues and that made a lot of sense in my brain. Regardless of that, I struggled with the 4x4 the most for some reason. By the end of that, I felt like I grasped the concept better. I appreciate the smaller puzzles as a stepping stone for the bigger puzzles. It really gave me a good hold on it. I felt like I was able to do part 2 much better. For part 3, I felt a little overwhelmed. I thought for sure it was going to be the big line that was used as the break-in, but to my shock, box 7 was surprisingly restrictive. It is kind of insane how only one possible combination worked there. I am impressed by that setting, which is no surprise as these were constructed by two brilliant setters. The same kind of restriction also happened on the three length line in box 3. That is so cool how that works out. I very much enjoyed each of these puzzles. I felt like I got better with each one. Great Puzzles!
It's quite a coincidence that today both Simon and Mark pointed out an area of the puzzle that would cause uniqueness problems, and then mentioned that they wouldn't use it as part of the solve because it wouldn't demonstrate that there is only one unique solution to the puzzle, which is part of what they are doing with their solve. This is a fairly rare comment on the channel, so very unusual that they would both say it on the same day.
At 12:13 why could the green line not be 4 differences of 4? There are never more than 2 cells in a row/collom/box so they could just alternate between 1&5/2&6 right? Edit: he figured it out around 14:40
Lovely idea. As usual it took me a while to catch on. Solved the first one in something like 45 minutes, the second took me ~4 hours, and got the third in 01:38:42. Actually learning a lot of the implications in part 2 made part 3 a very smooth solve for me, although I was still pleasantly surprised by the long line's configuration in part 3.
Actually, after checking my solution, it couldn't be a 5 because in R2 there was already a 3 so R2C1 and R2C2 were known to be a 15 pair but C1 already had a 5 in it so he knew already though he had not yet filled them in that R2C1 had to be 1 and R2C2 had to be 5 therefore R5C2 had to be 1.
3 puzzlea from two of my favourite constructors, recommended by a third! Sign me up! A great new constraint and a fabulous set of puzzles. Exactly as you'd expect from Sujoyku and Marty Sears.
Part I - 00:57 finish Part II - 07:03 finish Part III - 15:41 finish Total - 23:41 finish I didn't even think about parity shading until a few minutes into Part III, but it definitely made a difference (and showed some differences too 🤣). An interesting series of puzzles!
Thanks, very engrossing puzzles. At first I thought I would struggle but it was interesting to see different bits of logic emerge and I ended up doing all three in about the same time as Mark. Though I didn't use any colouring.
28:30 I think a good way of articulating what you're saying is that with three 3s and one 1, you're looking at a "total" of 10 increments. They must be equalized to land back on a 6, so 5 up and 5 down in some way. There's no way to make 5 with three 3s and one 1.
My brain kind of went the way off Mark's explanation, but your explanation does make sense and it's always so interesting to see different ways of thinking👌
19:37 for the 9x9. The rule seemed like it'd be a lot harder than it actually was. Also happy to be able to use uniqueness in the green square line to skip over considering 1,5,1,5 and guaranteeing 1,5,9,5.
The main reason i understood this was because Nils was kind enough to walk me through some of the logic! I honestly like this constraint better than counting circles.
Why exactly do we exclude difference of 0? For instance, in the first puzzle green line can go 3-4-4 or 4-3-3 with the dot being 1-2, and all it all works. Perhaps a correction to the rules is needed, I was staring at an empty 4x4 for 10 minutes before coming here to Mark for pointers :)
I cant believe I completed all 3 puzzles. I finished the first in 56 seconds but then struggled with the other two, taking about 25 and 35 minutes respectively. I didn't use parity though hardly at all other than seeing it in box 7 of puzzle 3.
2:23 / 13:16 / 19:11 (Total: 34:50) ... I fared better on the third one than the second one, but I'm just content to get through all three of these Nice puzzles!
The big one looked daunting at first, but one you get into it I think they made the choices fairly easy. I suspect they could have made it much harder,
There is nothing quite as daunting as seeing a 4x4 grid given as an introduction to a puzzle type... Not as scary as I feared, though. Some fun parity puzzles.
…which is strange because the timestamps are in the Description: clearly something hath glitched somewhere, and I don't think we can blame the CtC folks…
I finished part 1 in 4:15 but I didn't feel good about the solve because I went off a hunch and happened to get it all right on the first try without even testing the other possibilities. And as the number of potential differences increase exponentially, I'm giving up there. I don't like this ruleset very much, I don't think.
Thankyou very much Mark for this unexpected feature! The idea for this constraint was Sujoyku's, and he asked me if I wanted to collab on it because it is basically a mash-up of my two favourite constraints that I've come up with - counting circles and same / different difference lines. Of course I said yes straight away and it was a huge pleasure working with him on it.
He first set a 6x6 which I thought was great, and I suggested it would be nice to make this into a 3-parter, with a nice introductory 4x4 and a more meaty 9x9 where some other different implications and silliness can be explored. He set the 4x4 too which I thought served as a perfect part 1 - as Mark said, it is surprisingly not-trivial - I think the difficulty was judged perfectly there.
I made the 9x9, and from the start I knew I wanted a square with differences of 4, and a long stupid line which ends up getting 1 and 9 forced next to each other on it to make for a fun little moment. Forcing that 1-9 in a natural way was the biggest challenge of setting this, but overall it was quite a smooth and quick one to set.
Great invention by Sujoyku and I think the constraint has legs to be combined with other rulsesets. This is something we may explore more after Christmas :)
Also thankyou to Juggler for the very kind recommendation!
That 1-9 line being so daunting but actually falling apart was magical!
I was impressed by the gentle ways that we were introduced to this wonderful new rule! Congratulations Marty and Sujoyku on another brilliant puzzle! And thanks to Mark for featuring it, and Juggler for recommending it! 🙂
This is one of my favorite puzzles. I always love parity puzzles, and finding that from these rules was very great.
Glad it got featured!
Thank you for this wonderful feature, Mark! I loved how you found out about the parity changes along the length-5-difference lines and put it too good use immediately. It was also very nice to see you acknowledging the impossibility of difference 0. (Fun fact: This observation can already be used as a deduction in the 4x4 intro puzzle.) Thank you so much for your incredibly kind words in the end!
Last but not least, I want to give a big shoutout to Marty Sears. As you probably all know his rat run series, I do not have to tell you what a fantastic setter he is. But he is also one of the most kind and helpful people I know and it was a true pleasure to work with him. Thank you for this fun collaboration and for all your support, Marty!
It's completely terrible wording. You can have a difference of 0, and that would be the only way to have a 5 long line, because between two same digits is no difference. The solution here is complete garbage with a difference of 1 then three pairs with 3. The description is totally misleading
@@JP-yu1qc A difference of zero would mean there was zero pairs with that difference on the line, so it's not possible.
@@JP-yu1qc Regardless of whether you are right or wrong in your comment (and in this case you are totally wrong), using that tone to address someone on this channel, especially a setter, is utterly rude.
If Mark uses a different interpretation of the rules than you, you can be sure that you have it wrong..
The polite thing to do in that case, is to suggest a better phrasing of the rules.
@@JP-yu1qc Glad you enjoyed it JP 🙂
I needed the 4x4 to learn to use the rule and the 6x6 to learn how to do the 9x9. A nice ruleset. A lovely video
Mark, I am in awe of your mind. I have no idea how you grasped all that so easily; all the kudos to you for it.
Agreed. He grasps the concepts so fast! While talking to an audience. Just wild 🤩
My joy has increased by 1) watching this video (which increases my joy daily, I will add); 2) enjoying your joy, Mark ... I have not tried the puzzles, but I think I will do so, having watched you solve these. I am always amazed at how readily your mind grasps the parity implications of some of the variant rules that you encounter. I really need to beef up my parity thinking, because I am sure it would help me solve sudoku puzzles faster - and probably with more joy! Thanks so much for this video.
For that 11 cell line in the last puzzle, you should have suspected it would be something ridiculous like eight 8s and two 2s as soon as you saw "Marty Sears." lol
I finished Part 1 in 10:30 minutes, Part 2 in 12:07 minutes, and Part 3 in 43:55 minutes for a total of 66:32 minutes. I was a little confused at first until Mark described it as being similar to the counting circles clues and that made a lot of sense in my brain. Regardless of that, I struggled with the 4x4 the most for some reason. By the end of that, I felt like I grasped the concept better. I appreciate the smaller puzzles as a stepping stone for the bigger puzzles. It really gave me a good hold on it. I felt like I was able to do part 2 much better. For part 3, I felt a little overwhelmed. I thought for sure it was going to be the big line that was used as the break-in, but to my shock, box 7 was surprisingly restrictive. It is kind of insane how only one possible combination worked there. I am impressed by that setting, which is no surprise as these were constructed by two brilliant setters. The same kind of restriction also happened on the three length line in box 3. That is so cool how that works out. I very much enjoyed each of these puzzles. I felt like I got better with each one. Great Puzzles!
It's quite a coincidence that today both Simon and Mark pointed out an area of the puzzle that would cause uniqueness problems, and then mentioned that they wouldn't use it as part of the solve because it wouldn't demonstrate that there is only one unique solution to the puzzle, which is part of what they are doing with their solve. This is a fairly rare comment on the channel, so very unusual that they would both say it on the same day.
At 12:13 why could the green line not be 4 differences of 4? There are never more than 2 cells in a row/collom/box so they could just alternate between 1&5/2&6 right?
Edit: he figured it out around 14:40
I came here looking for a comment at the same point, thanks
Lovely idea. As usual it took me a while to catch on. Solved the first one in something like 45 minutes, the second took me ~4 hours, and got the third in 01:38:42. Actually learning a lot of the implications in part 2 made part 3 a very smooth solve for me, although I was still pleasantly surprised by the long line's configuration in part 3.
Genuinely original idea. Absolutely excellent video, showing the evolution of that idea. Another great CTC milestone. 😏👍👍👍
In the second puzzle, at 17:43, r5c2 could have still been a 1 or a 5 when Mark placed a 1 in it.
This is true; although it’s not a major skip. First place 3 in box 1, then box 5, and everything proceeds from there.
Actually, after checking my solution, it couldn't be a 5 because in R2 there was already a 3 so R2C1 and R2C2 were known to be a 15 pair but C1 already had a 5 in it so he knew already though he had not yet filled them in that R2C1 had to be 1 and R2C2 had to be 5 therefore R5C2 had to be 1.
@@afanofosc That's a whole lot of retconning to say "Yeah, he overlooked that possibility"
@@afanofosc Yes, I know you can logically deduce that it can't be a 5. But Mark didn't do that. That was my point.
“My life is better for doing that puzzle” haha! Mine too, for watching you do it.
3 puzzlea from two of my favourite constructors, recommended by a third! Sign me up!
A great new constraint and a fabulous set of puzzles. Exactly as you'd expect from Sujoyku and Marty Sears.
"I enjoy doing sudoku in my sudoku puzzles." ~ Clearly Not Simon
Part I - 00:57 finish
Part II - 07:03 finish
Part III - 15:41 finish
Total - 23:41 finish
I didn't even think about parity shading until a few minutes into Part III, but it definitely made a difference (and showed some differences too 🤣). An interesting series of puzzles!
05:13 learning the rules at first
15:30 understanding the rules at second
20:01 using the rules at third
Thanks, very engrossing puzzles. At first I thought I would struggle but it was interesting to see different bits of logic emerge and I ended up doing all three in about the same time as Mark. Though I didn't use any colouring.
Wonderful puzzles. Especially the 3rd one was very exciting.
28:30 I think a good way of articulating what you're saying is that with three 3s and one 1, you're looking at a "total" of 10 increments. They must be equalized to land back on a 6, so 5 up and 5 down in some way. There's no way to make 5 with three 3s and one 1.
My brain kind of went the way off Mark's explanation, but your explanation does make sense and it's always so interesting to see different ways of thinking👌
Interesting ruleset!
My times:
1. 1:39
2. 5:38
3. 16:54
19:37 for the 9x9. The rule seemed like it'd be a lot harder than it actually was. Also happy to be able to use uniqueness in the green square line to skip over considering 1,5,1,5 and guaranteeing 1,5,9,5.
The main reason i understood this was because Nils was kind enough to walk me through some of the logic! I honestly like this constraint better than counting circles.
Monstrously fast solve on the last one, well done!
Part 1: 5:46 and solver #2076
Part 2: 11:52 and solver #1064
Part 3: 39:08 and solver #742
Why exactly do we exclude difference of 0? For instance, in the first puzzle green line can go 3-4-4 or 4-3-3 with the dot being 1-2, and all it all works.
Perhaps a correction to the rules is needed, I was staring at an empty 4x4 for 10 minutes before coming here to Mark for pointers :)
I cant believe I completed all 3 puzzles. I finished the first in 56 seconds but then struggled with the other two, taking about 25 and 35 minutes respectively. I didn't use parity though hardly at all other than seeing it in box 7 of puzzle 3.
2:30, 12:59, and 29:09 were my times. How fun that was!
A relaxed 18:00 on the 9x9, much simpler than I thought it would be
Not as quick as you but once I actually got started it went remarkably quickly - it was finding the way in that took the time.
2:23 / 13:16 / 19:11 (Total: 34:50) ... I fared better on the third one than the second one, but I'm just content to get through all three of these
Nice puzzles!
I loved this
It was very interesting
When imported into sudoku pad, the check function says all digits are wrong
24:00 Mark asks how can R2C2 be 8, had he gone in to ask how could it be 3 he might have made some faster progress.
My life is better for this puzzle and video
Part 1: 00:02:50
The big one looked daunting at first, but one you get into it I think they made the choices fairly easy. I suspect they could have made it much harder,
definitely could have, but I don't think that would have made it more fun :)
Would a difference of 0 be possible?
No because having at least 1 difference of 0 contradicts the resulting requirement that you have 0 differences of 0
All of the lines have zero differences of 0. 😁😁😁
There is nothing quite as daunting as seeing a 4x4 grid given as an introduction to a puzzle type...
Not as scary as I feared, though. Some fun parity puzzles.
This video is without chapters.
…which is strange because the timestamps are in the Description: clearly something hath glitched somewhere, and I don't think we can blame the CtC folks…
@@PhilBoswell I don't blame our two friends. They are giving us too much already...
I finished part 1 in 4:15 but I didn't feel good about the solve because I went off a hunch and happened to get it all right on the first try without even testing the other possibilities. And as the number of potential differences increase exponentially, I'm giving up there. I don't like this ruleset very much, I don't think.
Not the most interesting constraint even a little annoying. In the last weeks i think a few of the puzzles were not chosen very well.