gdc here. Thanks for this feature and also to you Simon, for the idea. I only set one yin yang puzzle before this one and both time I had so much fun doing it. Hope you are all having a great start into the new year!
@@PeterZaitcev Yes, I actually thought about not giving a shading for that reason but then decided it might lead to confusion so I put a "redundant" orange into box 9.
I think what I appreciate the most about these videos is how accessible they are. No matter how common a bit of logic might be, you and Mark always take the time to explain it, even something as basic as what it means when we're told "Normal Sudoku rules apply". Thank you for all the efforts!
I initially shared Simon's trepidation about negative digits in the grid but you can always trust gdc to deliver a quality experience; they've proven themselves as both a master of Zipper logic and now a master of Fog-of-War as well. Looking forward to their next appearance!
This was a longer video length that I usually attempt, but I just love Fog of War so much and think I've nearly solved every one on the channel, so I bookmarked this one to try at some point. Glad I finally did! What a joy to solve, and like so many FoW puzzles, the solution path felt pretty straightforward. 26:21 solve time!
I pulled a simon on this one... I did 80% of the puzzle and then got stuck until I realized my 8,9 pair in box 9 could be resolved because I had gotten the other two digits ages ago.... Still beat it in sub 30 min which makes me happy Thanks for the great puzzle:)
45:36 for me. The puzzle works if you flip the shading, so you could've ignored the orange in R9C8 (or shaded it something else to mean negative) and it will still solve in the same way.
This was my first thought as well. Then I also came to the conclusion that the cells having the same polarity is the important part and "positive" vs "negative" is arbitrary.
Same thought here, but only because I misread the rules and thought orange was negative. Started solving a bit, realized mistake and wondered if doing it backwards would've worked.
Uncharacteristically for me, I got that one reasonably fast in 27:07, and it was a lot of fun. I generally enjoy both fog of war and ying yang puzzles, and this was a marvelous combination of both.
Finished in 28:33. I enjoyed this a lot! Not too difficult with the weird negative maths, and the fog helped keep me on track without getting overwhelmed by the whole grid at once.
Finished in 33:41. What absolutely lovely logic to go from one step to the next. I loved the mix of switching from figuring out what possible digits could be where on the zipper lines to transitioning to make sure that the shaded cells couldn't form a 2x2 to figuring out which shaded cells were connected to going back to figuring what was on the zipper line. Very fun puzzle!
Not sure about the logic around 53:00 where Simon is assuming those two line-tips are the ends of the line in the central box. We've already seen that zipper lines are able to overlap cells in this puzzle, so I don't think it's valid to assume that that line necessarily extends on to r5c3; that could be part of a different zipper. (The puzzle is still solvable without that assumption.)
33:10 finish. I had a bit of a false start, screwing up my addition on the line along column 9. But once I rewound and rethought for a minute, I was able to push through and follow the logic. Yin Yang and math, an excellent combination. Fun fun fun puzzle!
Regarding the badly rated fog puzzles, I suspect these are people who know perfectly well how you're supposed to do it, they just failed to solve it. For fog puzzles, and only for fog puzzles, it is possible for someone who failed to solve the puzzle to then brute force it and rate it anyway.
It's also possible for any sudoku variant that only contains common rules. In that case, someone can pop the puzzle into f-puzzles and have it solve it for them. Certainly easier for fog puzzles, and puts them at a significant rating disadvantage. But it also puts puzzles with unique rules at an advantage, so we probably see more of those on the channel than we would otherwise.
Wow! I finished in 42:29. I saw the hour-plus video and was expecting a monster, but this flowed very easily for me. I never felt hopelessly stuck through the whole thing, but I was making interesting deductions throughout. Great puzzle!
I needed a little help to get me started, but once I got to 25:21 in the video, I was able to take it the rest of the way myself. Usually I get stuck on the harder ones and only finish the solve with about 10 minutes left in the video, so I'm really happy getting there with still 1/2 hour left...
at 1:01:45 watching him reduce box 4 row 6, not seeing that 1/9 pair in row 4 and row 5 so that is a 1/9 pair and watch him eliminate digits one by one was slightly painful.
@49:30 reminds me of pixel hunting in old Point & Click Adventure Games. Great eyes btw & great solve. I was fortunate enough to get to test this one for gdc. :)
32:57 Absolutely brilliant. Would love to see more negative values used. Note that in this case reversing the shading leaves everything still correct, maybe the next version can use products (which would have the same feature!)😂
Interestingly, the puzzle is equally as solvable without that initial slight-orange shading - by simply negating every number in the puzzle, the given rules and constraints must all still hold. So it doesn't matter which set is positive and which is negative - both will work!
@@HunterJE I suppose that's true - for some reason I usually only think of the digits themselves being the solution, while colorings and whatnot associated with the solution just being part of the solve path. I suppose it would be more correct to say: even without knowing which set is positive and which is negative, you can still obtain a single unique set of digits which provably satisfy the constraints.
gdc here. Excellent point made in this comment. I was thinking about leaving out the shading and mentioning that it's okay to not know which 'half' is positive and which 'half' is negative and I actually did that in another puzzle (Sub Zero Nabner). But eventually I thought, it's just going to lead to confusion in a puzzle that already sounds quite intimidating so I put an orange into evil edna.
And here I am, somehow not noticing initial colored cell, solved the puzzle wondering which of my colors should be orange XD😅 Only your comment helped me to get it 😅
Woah I actually solved it! Just a little bit of help from Simon at the beginning to figure out the perimeter shading, but after that it was smooth and awesome. Just at 49 minutes.
As far as I know, negative numbers were first used by *Jay Dyer,* the great master of *modifiers,* in three puzzles within their magnificent puzzle hunt: *Numeric Alchemy.*
That puzzle hunt was probably my favourite of the past 2 years. I did it again just a couple of weeks ago and was still amazed although I remembered parts of the logic. What a treasure of puzzles
@@meiter Yes, it was amazing, awesome, outstanding, magic. All puzzles with similar ruleset but better and better, each containing its own logic treasure. I wish I was Simon and could find the right adjectives to describe it.
At 1:02:30.. row 3 column 3 is the key digit and it forces row 6 column 2 to be orange. If you make row 3 column 3 blue.. the oranges have to get out and it forces 2x2s so to avoid that, row 5 column 2 has to be blue and again avoid 2x2 making it orange. If you make row 3 column 3 orange, again avoid 2x2 and it leads to row 6 column 2 to be orange regardless. Very elegant .. 🎉
Finally! Somebody did it, negative numbers in sudoku, so Simon couldn't say anymore "You can't put negative numbers in sudoku" 😁 Nice puzzle, 53:28 for me, but I've made some mistakes, last yin yang puzzle on this channel was a while ago, almost forgot how to solve them)
I think you're right. The line coming down from r5c3 in box 4 could have done something similar to the line coming down from r3c6. It could have turned left before reaching the centre of the cell, and not connected with the line coming from box 5. It's a bit unexpected, but then there's an example of a line doing this already in the grid, that one coming down from box 2.
Logic that doesn't rely on that assumption: We definitely know that r6c3 and r6c6 match, and sum to +1, so those two cells must contain consecutive digits. Simon's yin-yang logic showed that r6c3 must be one greater than r6c6. By sudoku, r6c6 can only be 3, 4, or 7. But 4 or 7 would force 5 or 8 into r6c3 - neither of which is possible. Therefore r6c6 must be 3, r6c3 must be 4, and we can see the rest of the line.
40:36, it really helps that the shading doesn’t matter outside showing +/- parity, I was really concerned at first in how little we had but just that flowed really well box to box
It took me 45:30 to find both solutions. But I knew from reading the rules that there couldn't be a unique solution unless there was a shaded cell hidden somewhere under the fog.
This was my first time ever trying the puzzle before watching your video (and also my first time doing a full variant sudoku puzzle) and it was even more interesting to watch you after trying my own approach to it.
Great puzzle 👍🏻 as we would expect from a gdc fog puzzle! It took me 35 minutes, so I was pleasantly surprised to beat the video length by so much, especially as this time I _don't_ think I bypassed any logic with lucky guesses! Glad to see that Simon had the same temporary brainfart that I did wondering if we could have a solitary unshaded cell in the perimeter in r9c9 before realising what a daft proposition that was 😜
19:00 I enjoy the words "interrupting orange" because it is a combination of the two most classic broken-format knock-knock jokes ("interrupting cow" and "orange you glad")
38:12 Something useful here - you can immediately color r2-3c7-since there's a 678 triple and a placed 9 in their box, neither can be higher than 5, yet they must sum to at least a +6, so they must both be positive...
I finally figured out something quicker than Simon. I had that first box figured out in about 5 minutes. I just went through the iterations of the numbers real quick. I don't have Simon's vast knowledge of puzzles, so I didn't get bogged down thinking about parity and whatnot. I also didn't waste time figuring out how r8c9 could be orange while r9c9 was blue, which was never possible.
at 53:32, is it logical to assume that r5c3 and r6c5 are the tips of the line centered on r4c5? we see that the line enters r6c3 from the northeast, but the line segment in r5c3 could be part of a separate line, with both lines passing through r6c3. Such as we see in r4c6.
53:27 I dont know if that was deliberate because I didn’t spot that at all, just ran through numbers and figured it out that way. Sometimes it’s a better/faster way to spots something like r6c6 that Simon pondered for a minute if it could be a 3 instead of asking if it can be anything else (which it can’t) 😊
I love fog of war puzzles. Proportionately, I am better at these than normal Sudokus. The fog limits where I have to look and so I lose less time on trying to deduce things in dead ends.
As much as I love fog of war puzzles I have to admit I understand why some purist sudoku solvers might not be big fans. I think the main issue is the fact that you will sometimes enter a wrong digit by making a wrong deduction and the fog won’t clear. That immediately tells you it is a wrong digit which is something sudoku shouldn’t usually tell you right away. The point of all sudokus is they don’t tell you whether you entered the right digit or not until you solved the whole thing. I always feel slightly uncomfortable if that happens to me as I no longer know if I can call my solve clean after that, I did get a hint during the solve after all, something I didn’t deserve. It makes fog of war sudokus forcing you to „cheat” unless you manage to solve the whole thing without a single error.
I git my book yesterday and I finished the Fog of War book tonight. One thing I will say about the fog of war is that it conditions you to get instantaneous feedback that youve entered a correct digit, you just don't get that with normap sudoku so it feels like you're missing something.
Enjoyed the puzzle. I think this in one of the only puzzles that clicked and I got to yell at Simon a little. I always like the puzzles you curate, though it takes me bit of time and a little help from the videos to solve. Just had to comment on the first time I beat you time, as strange as it may be. Cheers
74 minutes. Near the end, I inexplicably had some orange islands that didn't connect, but the numbers I had put in cleared the fog so I was pretty sure they were correct. It had to do with a mental error I made with the 3/6/9 in Box 4. Luckily, I was able to fix the colors without backtracking. Congrats to the designer for ignoring Simon's warning against negative numbers, and still beginning the instructions with "Normal Sudoku rules apply."
The plumbing nightmare that's going on in Simon's kitchen, he says. @2:35 or so: A "fatberg" or something was discovered, "Which he doesn't even want to know what it is." If you have a long front yard (the drainage pipe running the length under there to the sidewalk - it's a 30 or 45° angle from sidewalk to the main sewer line under the center of the road or something - "Whoosh" it goes). But if you have that "long front yard" (maybe 15° or 5° angle of the pipe all the way). Putting bacon grease (and even any kind of grease that will congeal) that grease is going to congeal along the way to the sidewalk/street). It's important for you folks to know this (if you are unknowingly putting grease down the kitchen sink that may congeal ). This is why my brother-in-law kept his hot water so hot (you had to be careful in the kitchen), he told me "The grease will harden as it goes to the street." Bacon grease and whatever put down that drain, is the cause . Don't do that (knowledge is power). They call it similar to an iceberg - but it's really just congealed (and VERY COLD like a block of ice). It's going to happen again (if you ignore this - you and your wife). Teach the kids, too. This is important (it's going to be their house someday). You're welcome. 😂🎉
We've since had Schroedinger cells, doublers, halvers, multipliers, fog of war with zero shown cells, and now negative numbers. Basiaclly, anytime Simon says, "Setters, don't even think about it" or "This violates the rules of Sudoku," the setters find a way to make it happen.
Feel better soon my friend. Hot tea and blanket along with CTC hoodie on the way to you. With of course the warmth of Simon's voice and his great solving for us.
@@davidrattner9 thank you, my friend. On medication which seems to be helping. Yes, plenty of hot tea! And Simon and your good wishes! And lots of naps.
52 minutes for me. It was a very enjoyable solve as I always felt like I was making slow but steady progress. No big walls I got stuck at for 10+ minutes.
l really liked this puzzle because l feel like it was exactly on my skill level. Not too easy but also fairly consistent progress to overall take about an hour. Exactly the challenge-level l was looking for and a fun ruleset to boot :]
I solved this puzzle thinking that the orange squares were negative, but it actually didn't matter. As long as you know one set is positive and the other set is negative it doesn't matter which one is which for this puzzle, since the line values you end up with don't change.
Another excellent solve! I can think of a way to sort of include fog of war puzzles in the next Greatest Hits volume: Include a page or two with the name and descriptions of the puzzles with QR codes linking to a site that hosts the puzzles.
![I.N "HALLUCINATION" | [Stray Kids : SKZ-PLAYER]](http://i.ytimg.com/vi/n5B5q1Hwt_U/mqdefault.jpg)
gdc here. Thanks for this feature and also to you Simon, for the idea. I only set one yin yang puzzle before this one and both time I had so much fun doing it. Hope you are all having a great start into the new year!
Is it true that reversing this puzzle's shading gives the second correct answer? Math won't change if you multiply EVERY number by a factor of -1.
@@PeterZaitcev Yes, I actually thought about not giving a shading for that reason but then decided it might lead to confusion so I put a "redundant" orange into box 9.
@@MrGrog90ahahah, I didn't even noticed it since I use the very same color for highlighting cells blocked by selection.
It's a very engaging puzzle. Well done!
@@MrGrog90 If you are going to play with Simon's head, play with Simon's head!
I think what I appreciate the most about these videos is how accessible they are. No matter how common a bit of logic might be, you and Mark always take the time to explain it, even something as basic as what it means when we're told "Normal Sudoku rules apply". Thank you for all the efforts!
I initially shared Simon's trepidation about negative digits in the grid but you can always trust gdc to deliver a quality experience; they've proven themselves as both a master of Zipper logic and now a master of Fog-of-War as well. Looking forward to their next appearance!
The two greatest storytellers on children's TV were Kenneth Williams and Bernard Cribbins.
Rules: 07:44
Let's Get Cracking: 11:48
Simon's time: 56m55s
Puzzle Solved: 1:08:43
What about this video's Top Tier Simarkisms?!
The Secret: 4x (06:52, 14:39, 14:44, 14:45)
Maverick: 2x (03:56, 04:00)
And how about this video's Simarkisms?!
In Fact: 14x (02:17, 08:37, 12:30, 16:29, 18:47, 25:41, 25:56, 29:28, 36:01, 37:16, 43:13, 43:45, 48:06, 59:00)
Ah: 12x (13:38, 14:29, 18:30, 18:30, 26:04, 28:08, 29:55, 34:48, 50:01, 50:35, 1:02:36, 1:06:19)
Beautiful: 11x (18:44, 18:44, 19:29, 19:31, 25:02, 30:20, 52:39, 53:19, 53:24, 58:25, 1:08:54)
Sorry: 10x (05:05, 05:14, 06:38, 08:48, 27:24, 38:31, 40:57, 41:47, 49:21, 1:01:33)
Hang On: 10x (24:48, 25:28, 28:25, 33:25, 39:11, 40:45, 40:45, 48:41, 59:16, 1:06:56)
Checkerboard: 10x (14:51, 15:37, 15:44, 20:36, 40:33, 44:08, 50:48, 51:15, 53:15, 1:05:08)
By Sudoku: 8x (31:51, 37:51, 46:02, 1:03:52, 1:07:11, 1:08:10, 1:08:26)
Pencil Mark/mark: 8x (32:34, 32:37, 46:24, 48:20, 56:01, 56:57, 1:00:27, 1:06:52)
What Does This Mean?: 6x (10:56, 15:27, 26:42, 39:09, 50:01, 56:34)
Gorgeous: 5x (24:49, 24:53, 36:55, 36:59, 1:09:05)
Clever: 4x (30:36, 34:13, 1:08:50, 1:08:54)
Brilliant: 3x (02:01, 02:06, 1:08:32)
Wow: 3x (20:42, 1:08:39, 1:08:39)
Cake!: 3x (04:19, 04:32, 05:52)
Goodness: 2x (18:47, 26:15)
The Answer is: 2x (34:03, 53:09)
Break the Puzzle: 2x (15:51, 16:31)
Extraordinary: 2x (20:03, 20:06)
Shouting: 2x (04:51, 1:07:46)
Obviously: 2x (15:16, 47:18)
What on Earth: 1x (35:28)
Apologies: 1x (1:07:46)
Nonsense: 1x (28:08)
Take a Bow: 1x (1:08:39)
Witty: 1x (1:08:54)
Surely: 1x (45:21)
I've Got It!: 1x (28:46)
Intriguing: 1x (14:36)
Progress: 1x (49:37)
Chromatic: 1x (09:46)
Fabulous: 1x (1:09:49)
That is Sick: 1x (24:58)
Have a Think: 1x (56:55)
Weird: 1x (40:04)
Most popular number(>9), digit and colour this video:
Ten (5 mentions)
Two (88 mentions)
Blue (43 mentions)
Antithesis Battles:
Low (3) - High (1)
Even (21) - Odd (4)
Shaded (6) - Unshaded (5)
Higher (2) - Lower (1)
Row (6) - Column (5)
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!
This was a longer video length that I usually attempt, but I just love Fog of War so much and think I've nearly solved every one on the channel, so I bookmarked this one to try at some point. Glad I finally did! What a joy to solve, and like so many FoW puzzles, the solution path felt pretty straightforward. 26:21 solve time!
I pulled a simon on this one... I did 80% of the puzzle and then got stuck until I realized my 8,9 pair in box 9 could be resolved because I had gotten the other two digits ages ago....
Still beat it in sub 30 min which makes me happy
Thanks for the great puzzle:)
45:36 for me. The puzzle works if you flip the shading, so you could've ignored the orange in R9C8 (or shaded it something else to mean negative) and it will still solve in the same way.
I was wondering how Simon determined that r8c8 and r9c8 were both positive at the start, then I made the same realization as you, works either way
This was my first thought as well. Then I also came to the conclusion that the cells having the same polarity is the important part and "positive" vs "negative" is arbitrary.
@@jakesullivan8220 Probably because r9c8 was already shaded orange in the puzzle setup.
Same thought here, but only because I misread the rules and thought orange was negative. Started solving a bit, realized mistake and wondered if doing it backwards would've worked.
I'm colorblind and could not tell if that cell was orange, so I was just completely stuck.
I'm so glad I found this puzzle!!! It has my favorite constraints, yin/yang (shading) and fog! Lovely solve in 47 minutes
Uncharacteristically for me, I got that one reasonably fast in 27:07, and it was a lot of fun. I generally enjoy both fog of war and ying yang puzzles, and this was a marvelous combination of both.
Me too. Done in 29:15. I got the perimeter in 30 seconds and box 9 worked out in about 3 minutes.
I'm always astounded at how these setters can create these masterpieces. Great puzzle!
Finished in 28:33. I enjoyed this a lot! Not too difficult with the weird negative maths, and the fog helped keep me on track without getting overwhelmed by the whole grid at once.
What a nice flow to the puzzle gdc! Great concept with the yin-yang and negative numbers summing on the lines. Just marvellous. Well done
Finished in 33:41. What absolutely lovely logic to go from one step to the next. I loved the mix of switching from figuring out what possible digits could be where on the zipper lines to transitioning to make sure that the shaded cells couldn't form a 2x2 to figuring out which shaded cells were connected to going back to figuring what was on the zipper line.
Very fun puzzle!
27:14 for me. What a great puzzle. That cheeky one with the 2 toward the end was delightful
I enjoyed this very much - I did not solve the puzzle, but I loved watching you do it, Simon. Thank you!
Maaaaggg-nificent!!! Big ups to gdc , Simon and all of you awesome people!
Loved this one! It took me about 2 hours and I had to take a little peak at Simon a couple of times for a clue, but I enjoyed it a lot! :)
That was just superb. Not radically difficult, but I had a smile on my face throughout. 70 mins for me.
36:03 - very rare that I beat Simon's time!
Excellent video and puzzle (as always!)
I did too! In 40 minutes!
This is so good! Absolutely amazed at how clever the deductions kept being.
Not sure about the logic around 53:00 where Simon is assuming those two line-tips are the ends of the line in the central box. We've already seen that zipper lines are able to overlap cells in this puzzle, so I don't think it's valid to assume that that line necessarily extends on to r5c3; that could be part of a different zipper.
(The puzzle is still solvable without that assumption.)
33:10 finish. I had a bit of a false start, screwing up my addition on the line along column 9. But once I rewound and rethought for a minute, I was able to push through and follow the logic. Yin Yang and math, an excellent combination. Fun fun fun puzzle!
Don't forget the Moog and Carwash the green cat. Used to love Willo the Wisp too :D
This puzzle rocks. Gonna watch the rest of the video now
Regarding the badly rated fog puzzles, I suspect these are people who know perfectly well how you're supposed to do it, they just failed to solve it. For fog puzzles, and only for fog puzzles, it is possible for someone who failed to solve the puzzle to then brute force it and rate it anyway.
It's also possible for any sudoku variant that only contains common rules. In that case, someone can pop the puzzle into f-puzzles and have it solve it for them. Certainly easier for fog puzzles, and puts them at a significant rating disadvantage. But it also puts puzzles with unique rules at an advantage, so we probably see more of those on the channel than we would otherwise.
Wow! I finished in 42:29. I saw the hour-plus video and was expecting a monster, but this flowed very easily for me. I never felt hopelessly stuck through the whole thing, but I was making interesting deductions throughout. Great puzzle!
Lovely puzzle, thanks, and a much smoother solve than I was anticipating when I saw the word "negative".
31:44! More yin yang sudokus please, my mind seems to really just get them :D
Very satisfying to solve this. That the negatives nearly reverse all the rules we know about zippers is awesome. Well done!
Thank you for highlighting this truly joyous puzzle! This was one of my all-time favorites
I needed a little help to get me started, but once I got to 25:21 in the video, I was able to take it the rest of the way myself. Usually I get stuck on the harder ones and only finish the solve with about 10 minutes left in the video, so I'm really happy getting there with still 1/2 hour left...
Another great puzzle from gdc! I had a lot of fun solving this. The choice to combine yin-yang with positive-negative is beautifully thematic.
Super enjoyable puzzle, the way it flicked back and forth between different kinds of logic. 01:20:01 for me with no help.
55:54 rare that I beat Simon's time, even with the handicap of him explaining it to us. Very well constructed puzzle. A blast from start to finish.
This was lots of fun! Thanks gdc and Simon
Shockingly straightforward for FOW with the shading rules. Best chance to beat Simon!
Solved in 01:38:23, but made a few mistakes
This is a rare puzzle where I didn't need Simon's help, yay
Thank you gdc, and thanks Simon
at 1:01:45 watching him reduce box 4 row 6, not seeing that 1/9 pair in row 4 and row 5 so that is a 1/9 pair and watch him eliminate digits one by one was slightly painful.
Box 5 could have been pencil marked much earlier based on the logic for the line there and sudoku, placing 4-5-6 in row 5, so 2-7 in row 6.
@49:30 reminds me of pixel hunting in old Point & Click Adventure Games. Great eyes btw & great solve. I was fortunate enough to get to test this one for gdc. :)
Loved it, and I beat Simon's time by a few minutes! Best of Sudoku, Vol. 3
32:57
Absolutely brilliant. Would love to see more negative values used.
Note that in this case reversing the shading leaves everything still correct, maybe the next version can use products (which would have the same feature!)😂
Interestingly, the puzzle is equally as solvable without that initial slight-orange shading - by simply negating every number in the puzzle, the given rules and constraints must all still hold. So it doesn't matter which set is positive and which is negative - both will work!
But then the puzzle is no longer unique - there are two equally valid solutions (similar to if you have uninterrupted like pairs in an X-wing pattern)
@@HunterJE I suppose that's true - for some reason I usually only think of the digits themselves being the solution, while colorings and whatnot associated with the solution just being part of the solve path.
I suppose it would be more correct to say: even without knowing which set is positive and which is negative, you can still obtain a single unique set of digits which provably satisfy the constraints.
gdc here. Excellent point made in this comment. I was thinking about leaving out the shading and mentioning that it's okay to not know which 'half' is positive and which 'half' is negative and I actually did that in another puzzle (Sub Zero Nabner). But eventually I thought, it's just going to lead to confusion in a puzzle that already sounds quite intimidating so I put an orange into evil edna.
Correct. Multiply an entire equation by -1 and it is still a true equation.
And here I am, somehow not noticing initial colored cell, solved the puzzle wondering which of my colors should be orange XD😅
Only your comment helped me to get it 😅
Woah I actually solved it! Just a little bit of help from Simon at the beginning to figure out the perimeter shading, but after that it was smooth and awesome. Just at 49 minutes.
As far as I know, negative numbers were first used by *Jay Dyer,* the great master of *modifiers,* in three puzzles within their magnificent puzzle hunt: *Numeric Alchemy.*
That puzzle hunt was probably my favourite of the past 2 years. I did it again just a couple of weeks ago and was still amazed although I remembered parts of the logic. What a treasure of puzzles
@@meiter Yes, it was amazing, awesome, outstanding, magic. All puzzles with similar ruleset but better and better, each containing its own logic treasure.
I wish I was Simon and could find the right adjectives to describe it.
27:31, just flowed for me, spun my wheels for a minute at the end forgetting about the very start of the puzzle and me not finishing using that line.
At 1:02:30.. row 3 column 3 is the key digit and it forces row 6 column 2 to be orange.
If you make row 3 column 3 blue.. the oranges have to get out and it forces 2x2s so to avoid that, row 5 column 2 has to be blue and again avoid 2x2 making it orange.
If you make row 3 column 3 orange, again avoid 2x2 and it leads to row 6 column 2 to be orange regardless. Very elegant .. 🎉
Finally! Somebody did it, negative numbers in sudoku, so Simon couldn't say anymore "You can't put negative numbers in sudoku" 😁
Nice puzzle, 53:28 for me, but I've made some mistakes, last yin yang puzzle on this channel was a while ago, almost forgot how to solve them)
At 52:11 how does simon know how the line goes on in box 4? Couldn't the little part you see in box 4 just be from another zipper?
Good catch!
I'm not sure, but I think in this situation, when you have several lines in the cell, the lines are not centered.
(Like in R4C56)
because the zipper going from box4 into box3 has to use exactly 2 squares in box 3 so you can tell that the other end of the zipper is r6c5.
I think you're right. The line coming down from r5c3 in box 4 could have done something similar to the line coming down from r3c6. It could have turned left before reaching the centre of the cell, and not connected with the line coming from box 5.
It's a bit unexpected, but then there's an example of a line doing this already in the grid, that one coming down from box 2.
Logic that doesn't rely on that assumption:
We definitely know that r6c3 and r6c6 match, and sum to +1, so those two cells must contain consecutive digits. Simon's yin-yang logic showed that r6c3 must be one greater than r6c6.
By sudoku, r6c6 can only be 3, 4, or 7. But 4 or 7 would force 5 or 8 into r6c3 - neither of which is possible. Therefore r6c6 must be 3, r6c3 must be 4, and we can see the rest of the line.
Thanks for another great showing of a fog of war! Can't wait to watch it
Nice puzzle. 45 minutes here. Thanks for sharing it.
Did not dare to try. But your solve was amazing to this clever and beaufiful puzzle. The fog just make it better! Thanks for it 😊
40:36, it really helps that the shading doesn’t matter outside showing +/- parity, I was really concerned at first in how little we had but just that flowed really well box to box
40:59 for me. Brilliant puzzle and not too difficult. Thanks Simon for giving GDC the idea.
24:11 For me, very fun logic, I liked the way line between box 5 and 8 interacted with the coloring once you get to it
It took me 45:30 to find both solutions. But I knew from reading the rules that there couldn't be a unique solution unless there was a shaded cell hidden somewhere under the fog.
Absolutely amazing! Great puzzle and a stunningly good solution path. Well done.
This was my first time ever trying the puzzle before watching your video (and also my first time doing a full variant sudoku puzzle) and it was even more interesting to watch you after trying my own approach to it.
Great puzzle 👍🏻 as we would expect from a gdc fog puzzle! It took me 35 minutes, so I was pleasantly surprised to beat the video length by so much, especially as this time I _don't_ think I bypassed any logic with lucky guesses! Glad to see that Simon had the same temporary brainfart that I did wondering if we could have a solitary unshaded cell in the perimeter in r9c9 before realising what a daft proposition that was 😜
1:11:06 - What a fantastic puzzle that was! Pure genius.
I had a ton of fun doing this one! It’s been too long since I tried one before watching Simon’s solve. 88.02!
I remember Kenneth Williams as the guy in the "Carry On" films, which probably doesn't reflect well on how cultured I am.
19:00 I enjoy the words "interrupting orange" because it is a combination of the two most classic broken-format knock-knock jokes ("interrupting cow" and "orange you glad")
38:12 Something useful here - you can immediately color r2-3c7-since there's a 678 triple and a placed 9 in their box, neither can be higher than 5, yet they must sum to at least a +6, so they must both be positive...
I finally figured out something quicker than Simon. I had that first box figured out in about 5 minutes. I just went through the iterations of the numbers real quick. I don't have Simon's vast knowledge of puzzles, so I didn't get bogged down thinking about parity and whatnot. I also didn't waste time figuring out how r8c9 could be orange while r9c9 was blue, which was never possible.
at 53:32, is it logical to assume that r5c3 and r6c5 are the tips of the line centered on r4c5? we see that the line enters r6c3 from the northeast, but the line segment in r5c3 could be part of a separate line, with both lines passing through r6c3. Such as we see in r4c6.
@6:19
Simon's twin with a cap on.
It really, really could (I had to play it back to see if it was Simon skiing).
It's not, it's a "twin" (not).
😂🎉🎉
Simon making a 127 pencilmark in a box with 1 already in it made me actually laugh out loud. :D
I really loved this one! ❤
As a child in Canada in the 80's, we had several channels that aired British shows, mostly cartoons. Among them, Willow the Wisp. :D
Wonderful puzzle and not as difficult as I expected.
A suggestion for including fog puzzles in a best of book, is to include a QR code linking to the puzzle
53:27 I dont know if that was deliberate because I didn’t spot that at all, just ran through numbers and figured it out that way. Sometimes it’s a better/faster way to spots something like r6c6 that Simon pondered for a minute if it could be a 3 instead of asking if it can be anything else (which it can’t) 😊
that was just incredible, thanks for this awesome Puzzle :)
18:26 for me. fun fact: there is no way to disambiguate shaded or unshaded cells, so both assumptions are correct!
Apart from we're given r9c8 as shaded at the start.
I received my books today! So nice!
Took me a while to finish this, mainly as I was doing it between work. But really loved the solve.
I love fog of war puzzles. Proportionately, I am better at these than normal Sudokus. The fog limits where I have to look and so I lose less time on trying to deduce things in dead ends.
81 minutes for me, but it felt very aproachable, I was never stuck, just slow;) thanks for the puzzle.
As much as I love fog of war puzzles I have to admit I understand why some purist sudoku solvers might not be big fans. I think the main issue is the fact that you will sometimes enter a wrong digit by making a wrong deduction and the fog won’t clear. That immediately tells you it is a wrong digit which is something sudoku shouldn’t usually tell you right away. The point of all sudokus is they don’t tell you whether you entered the right digit or not until you solved the whole thing. I always feel slightly uncomfortable if that happens to me as I no longer know if I can call my solve clean after that, I did get a hint during the solve after all, something I didn’t deserve.
It makes fog of war sudokus forcing you to „cheat” unless you manage to solve the whole thing without a single error.
I git my book yesterday and I finished the Fog of War book tonight.
One thing I will say about the fog of war is that it conditions you to get instantaneous feedback that youve entered a correct digit, you just don't get that with normap sudoku so it feels like you're missing something.
Enjoyed the puzzle. I think this in one of the only puzzles that clicked and I got to yell at Simon a little. I always like the puzzles you curate, though it takes me bit of time and a little help from the videos to solve. Just had to comment on the first time I beat you time, as strange as it may be. Cheers
74 minutes. Near the end, I inexplicably had some orange islands that didn't connect, but the numbers I had put in cleared the fog so I was pretty sure they were correct. It had to do with a mental error I made with the 3/6/9 in Box 4. Luckily, I was able to fix the colors without backtracking. Congrats to the designer for ignoring Simon's warning against negative numbers, and still beginning the instructions with "Normal Sudoku rules apply."
The plumbing nightmare that's going on in Simon's kitchen, he says.
@2:35 or so:
A "fatberg" or something was discovered, "Which he doesn't even want to know what it is."
If you have a long front yard (the drainage pipe running the length under there to the sidewalk - it's a 30 or 45° angle from sidewalk to the main sewer line under the center of the road or something - "Whoosh" it goes).
But if you have that "long front yard" (maybe 15° or 5° angle of the pipe all the way).
Putting bacon grease (and even any kind of grease that will congeal) that grease is going to congeal along the way to the sidewalk/street).
It's important for you folks to know this (if you are unknowingly putting grease down the kitchen sink that may congeal ).
This is why my brother-in-law kept his hot water so hot (you had to be careful in the kitchen), he told me "The grease will harden as it goes to the street."
Bacon grease and whatever put down that drain, is the cause .
Don't do that (knowledge is power).
They call it similar to an iceberg - but it's really just congealed (and VERY COLD like a block of ice).
It's going to happen again (if you ignore this - you and your wife).
Teach the kids, too.
This is important (it's going to be their house someday).
You're welcome.
😂🎉
Somebody should turn these puzzles into an accredited 4-year baccalaureate degree...!
Fun puzzle. Thought it flowed very well.
When I look for Evil Edna, I get a mad TV, microwave or whatever.
Petition for gdc to make a fog of war puzzle composed solely of single pixel grid furniture
We've since had Schroedinger cells, doublers, halvers, multipliers, fog of war with zero shown cells, and now negative numbers. Basiaclly, anytime Simon says, "Setters, don't even think about it" or "This violates the rules of Sudoku," the setters find a way to make it happen.
Oh yay a foggy puzzle!! Home sick and this is my afternoon entertainment! So sorry about your plumbing problem!
Feel better soon my friend. Hot tea and blanket along with CTC hoodie on the way to you. With of course the warmth of Simon's voice and his great solving for us.
This is also me in a nutshell, thank you Simon for your videos and good luck getting the pipes all sorted!
@@davidrattner9 thank you, my friend. On medication which seems to be helping. Yes, plenty of hot tea! And Simon and your good wishes! And lots of naps.
@@rachelriesling9112 are you sick also? If so, hope you get well quickly!
@longwaytotipperary yup, got a hacking cough unfortunately. Fingers crossed we can both get some good rest and get back on our feet soon!
Zipper lines are quickly becoming one of the most versatile constraints; there's so much potential.
29:04 for me! Pretty straight forward logic but interesting piece
52 minutes for me. It was a very enjoyable solve as I always felt like I was making slow but steady progress. No big walls I got stuck at for 10+ minutes.
58 mins for me. Great fun!
Using scratch paper like they do in lotto tickets would make physical fog of war possible, although it'd certainly be super expensive
Yes but you'd have to know you wrote in the correct digit to know whether or not you should scratch it off and reveal the next clue
15:13 for me. Great puzzle!!
l really liked this puzzle because l feel like it was exactly on my skill level. Not too easy but also fairly consistent progress to overall take about an hour. Exactly the challenge-level l was looking for and a fun ruleset to boot :]
I solved this puzzle thinking that the orange squares were negative, but it actually didn't matter. As long as you know one set is positive and the other set is negative it doesn't matter which one is which for this puzzle, since the line values you end up with don't change.
Another excellent solve! I can think of a way to sort of include fog of war puzzles in the next Greatest Hits volume: Include a page or two with the name and descriptions of the puzzles with QR codes linking to a site that hosts the puzzles.
00:40:26 for me. Great Puzzle! Logic all the way for this fog! Kind Comment!
52:26 for me @3595
First time to finish faster than both Mark and Simon on the same day😂
Finished in 49:12 with some help from the video in getting started.