man i ramble so much in that video.. you guys are much more eloquent haha.. anyways, as always, cheers! 😊 EDIT: originally this was just a video to simon/mark to share this trick so my explanations aren't as in depth, my apologies, i think i would have explained things differently otherwise :)
Started watching your music videos, then baking some nerdy nummies, then playing chess against the try guys... you are everywhere! Great logic here, thanks for the tips
You and our friends who run this channel are certainly far better at this sort of thing than I could be, but: whenever I see incredible times on software games, I wonder about cheating. In particular, could it be there is other software spamming the puzzle site? (Also, when the puzzles are generated randomly and the leaderboard is for all puzzles, there's the possibility of ridiculously easy ones coming up randomly for some users and not others; I've seen this on a minesweeper web version once.)
This was 47 minutes of pure confusion for me. I'd never even heard of Star Battles before this video. Still, it's incredibly satisfying to see you solve such extreme puzzles!
TH-cam recommended one of your Sudoku videos to me & now I'm binging your channel. I'm a total puzzle noob, but you really awake my interest in them! Great work!.
Hmm - I've solved a *lot* of all kinds of logic puzzles, and uniqueness is something that you can use in any of them. I can't say I'd thought of it as being particularly prevalent in Star Battle though - interesting!
Cinderella Girls fan here with some interesting notes on the puzzle theming. For the 3-Star Mio puzzle, there's a character named Mio Honda whose theme song is called "Mitsuboshi", which literally translates to "three stars". On the 7-Star puzzle, "Abe Nana is forever 17" is a recurring joke for the character of Abe Nana, and "nana" means 7 in Japanese.
Around 37:40 it’s interesting how he goes into a lot more complicated logic when rows 3 and 5 already have two stars in each and a domino forcing a third star into them, meaning he can X off the entirety of the remainder of the rows.
This trick is actually so awesome, it took me a while to properly understand it and get better at spotting it. I've been playing 8x8 hard puzzles and it more than halved my time.
41:25 actually, it is helpful. It's the uniqueness thing KHS was talking about. You need 2 more stars in row 15, and if they're NOT in both columns 11 and 15, then the two stars in rows 14-15 and columns 11 & 15 would be swappable. So, they both have to be in columns 11 and 15, forcing our third and final star into row 14 column 13.
I have actually thought about this very point as I solved star battle puzzles before! But I never realised the full implications of uniqueness in star battle, like Kurt showed during his live solve of that puzzle with the interaction of the two cells below the P-pentomino shaped region. How nice! It really feels like there's a bunch of star battle logic out there that's just begging to be discovered.
I never knew this kind of puzzle was called a starbattle. I only knew it from an app I stumbled upon some time ago. It’s called Alberi and instead of stars you have to place trees. Now I’m really excited to get some more tips for solving the puzzles 😊
Those interjections really helped, I do understand the uniqueness thing as technique now. The things Kurt was pointing out went completely over my head however, and I have a feeling it's because of how new I still am to star battles lol
I got it!! I'm not even going to bother with the time because it took me about 2 hours. First time ever doing starbattles but the way of solving it was awesome! I ended up using linear equations to solve some parts too.
At 7:55, how does Kurt conclude there must be a star there? Couldn't both stars in that bottom right box be in the second last row and both stars in the bottom left box be in the bottom row (both of Simon's red highlights)? The greyed out boxes due to uniqueness make sense, but I'm missing something to place that star.
At 7:13 he says why, though he doesn't really explain it fully. The reason he says "you have to put a star down here otherwise there's not enough space" is because in 2 columns you need to place 4 stars. If there is no star in that bottom shape for those 2 columns, you need to place 4 stars in the empty spaces above it. There is going to be 1 star in the shape above (the one with only 2 white spaces left). That leaves the remaining 8 spaces above, which forms two 2x2 squares. You can only place 1 star in a 2x2 square since once you do it touches the other 3 squares, therefore the two 2x2 squares can only house 2 stars. So there are 2 stars in the top 8 squares, 1 star in the domino he has marked on row 7, so the 4th star MUST be in one of those 4 squares in the bottom shape. That means only 1 of the dominoes at the bottom of the bottom left shape can have a star, not both. Since placing a star in one of those 4 spaces allows you to swap it between the top and the bottom of those 4 spaces, the star in the bottom right shape must not be swappable. The only space in the bottom right shape that isn't swappable is the square he marks at 7:55. The other 6 can be swapped up and down.
Would have been nice if the M, I and O had been de-highlighted (or if there had been an option to uncolor them) in the last puzzle. Quite confusing trying to color-code the grid into stars/non-stars while a bunch of cells are already colored.
So, what makes uniqueness a great thing in star battle and frowned upon in sudoku? (honest question, I'd like to know what is different about these puzzles)...
The puzzle in the video is slightly different than the puzzle in the link. Specifically, the cell he designates as a star from uniqueness is in the other shape in the link!
Maybe that's an unpopular opinion, but I think uniqueness IS cheating. It is a shortcut that will get you through the puzzle faster, at the cost of verifying that it is a valid puzzle in the first place. If all you go for is speed, thats fine and you should absolutely use it. But if you solve a handcrafted puzzle without time pressure, you are taking away some of the fun for yourself by circumventing the logic that was put there by an author. And in a good puzzle, a fully logical path will be there to be found. While uniqueness arguments are interesting, they are a form of Metalogic and should never be confused with or viewed in the same category as normal logical steps.
Very interesting video. I'm not certain your explanation during your second interjection was 100% clear if someone didn't already follow, so I'll have a go at explaining it in a slightly different way: When you use a uniqueness trick find a particular solution that you know must be correct, you also know that there must still be something in the correct solution that FORCES it to be correct. And therefore, you should look to see what other features of the puzzle could force the solution you found through the trick. Often, there will only be one or two squares that, if they were stars, would force the solution you know is correct, and so you get even more restriction from the initial uniqueness trick.
I kind of get why the 2 positions at 7:25 are not possible, but why can you rule out the 3 on the bottom right? I don't really get that, can anyone explain ?
Never heard of Star Battles before but I was sending my thoughts really strongly that you would see the four red dominoes on the left. The top domino couldn't have a star in it's left hand side due to the shape below it. You got there eventually but it was sticking out to me like a red domino. The pain of watching puzzle solving, hah!
GAH! I'm still not following some of the uniqueness logic. Simon, would it be possible to do a star battle without using uniqueness then do it again with uniqueness?
Great Video! The uniqueness problem is really interesting. You could have used it to figure out row 4 and 6 much sooner because of uniqueness in the red dominoes in column 2 and 3.
I just feel totally lost. I dont understand either of those explanations. From the start it was okay, uniqueness... this cant be star, because you can do it the other way... but then in a next second... you cant do this, it must be the other way, then I got lost.
Its hard to wrap your head around. The way I understand it in the simplest form, if you have the right setup (two parallel sets of two-squares and the squares around them can't be stars), then in the solution the two stars must be on the same row, because if they were alternating then you could switch it. By being on the same row the stars force the other parts of the puzzle to be solved
Can anyone explain 9:46 more.. I understand it is not unique when placing a star in r10c3 or r10c4, but doesn't it works the same while placing a star in r9c3 or r9c4? I don't see why only r10c3 and r10c4 cannot be a star but r9c3 and r9c4 can...
I remember when these puzzles were in the New York Times Puzzle Mania 2019. If you would like to solve Starbattle (Two Not Touch as NYT calls it) Monday-Saturday in print.
i thing is I've heard the term uniqueness on this channel from Simon and it was always the line "i'm not going to use uniqueness to solve this" so hearing Kurt claiming to have never seen or heard of this technique being used confused me
So to give a possibly useless answer, I have indeed noticed the uniqueness possibility with star battles but have mostly just chosen to ignore it in favor of solving them in a more intended path. The trick is cool though! I definitely rely on uniqueness if I intend to solve a puzzle of any kind quickly(ish)
I don’t get the logic at 7:55. I get why the middle of the three cells he grays out can’t have a star, but why are all three precluded from having a star?
Oooooooooh. For the same reason. If either of those two other cells has a star, then we can just move things around *within the same block* and it’s not unique.
I'm a bit surprised at the "not cheating" comment, since I thought you've mentioned in previous videos that you don't like using uniqueness constraints in solves because they feel a bit cheaty.
I think a more interesting idea would be to explain how he ruled out so many squares to begin with. The top left is obvious (as there must be two in top right) but the next 6 rows !?
An interesting puzzle type I had never heard of before, and a cute/nifty trick for solving them for sure (at least I believe I understand the basics since "uniqueness is required for a solution, so any options which result in the puzzle being solved in two or more ways you can be sure is not true/rule out as possible." That at least goes back to the puzzle logic I do know for Sudoku which has the same principal in terms of "you did something wrong if two number pairs can flip-flop around and the puzzle is still solved.". That said, I have absolutely no idea what star battles beyond the very basics spelled out here and my general ability to understand it. What I and I assume most people who are completely unfamiliar with the concept until this video (which has got to be a lot of us because of the glut of new subscribers to this great channel) then the very fundamentals of a star-battle concept are lacking. The kinda stuff people who are familiar with the puzzle type would totally take for granted results in, say, watch Kurt start solving one of the blank puzzles. He immediately seems to figure out "must be a star here." But..why? I'm sure he is right, but I have no clue as to why. I assume somewhere online or perhaps on this very channel there is a "The basic solution solving techniques for star battle puzzles 101", if so it'd be great to include that in the video description for those of us who would like to follow along but are simply ignorant of some basic understands of solution/solving techniques and their underlying logic.
when discussing the fact that there must be a star in r3 c4/5. Why is that? That assumes solution has two stars in c8 c10 in different rows. And uniqueness alone forbids that (in that case one could simply swap those two pairs around just like he later shows with reasoning for bottoms of c1&3). So solution with star in r2c5 is impossible to start with
I have used this thinking in a path game called Maysu I think is the name. Often if I test a direction for a path it gives more than one way to continue the path so I know that the test must be wrong.
Hmmm, completed the first with a little difficulty. The third flowed really quickly and smoothly. The second I thought I had it, then realized I had a mistake, so I need to retry later. I'll hit #4 later on.
I knew there had to be another technique I was missing to solve these, I was always getting stuck looking for a logical path and put it down to low quality puzzles.
Maybe I'm not understanding properly. So there's a pair of dominoes on the grid which must contain 1 star each, and thus the stars' positions can swap interchangeably. And somehow by considering uniqueness they're able to realize which of those positions is valid? I don't follow the logic there. No matter what solution they end up with, if there's another arrangement of stars that fulfills the rules of star placement, surely that means their solution is non-unique as well?
It took me a while too. Look at column 9. If you place a star in R1C9, then it forces stars into R3C8 & R6C8. If you place a star into R7C9, then it forces stars into R1C8 & R6C8. Either way a star will go into R6C8.
@kvckelvin7 I was wondering the same thing. But if you put a star there (say R2C6), it blocks two squares from the shape right below it and forces its stars to at the ends of the remaining "Z" (i.e. R5C4, R4C6). At this point you would have tree stars on the same column (C6).
"Kurt's second puzzle" link takes you to a puzzle that is slightly different. The box in the bottom right is missing a square. I think that slightly different puzzle doesn't work.
I'll be honest and say that in the puzzle that starts at 6:33 I still don't follow the logic of this uniqueness property, even after both KHS and your explanations.
I didn't either. Especially since I quite literally never heard of a star battle puzzle, it would have been nicer to actually see what a star battle was before trying to go into an advanced strategy for speed solving them
When determining the 4 dominos in c2c3 you completely forgot about the topic of this video: Uniqueness. You had only 1 star left in c4 to force 2 stars into c2, so this star must touch 2 of the dominos, wherefore ou could immediately have Xed out r3c4 and r5c4 as here the star would only affect one of the doninos.
A bit unfortunate they went so in depth on KHS's new (?) trick and proceeded to never use it in Simons solve. There were at least 2 times it would have been very useful (and surely way more that my novice eyes didn't spot).
honestly, i get the filling up the spaces but the logic behind the areas and hypothetical lines is lost on me. Could you do a smaller/simpler puzzle or a tutorial on space battle puzzles altogether?
It's kind of funny, I came up with the Uniqueness method on one or two pencil puzzles on my own some time back… Uniqueness is by far a better name for it than my “Proof by Provability”
Second puzzle linked is broken. in row10, the bottom right object need at least 4 spaces, so the division should be betwen r10c6 - r10c7. instead of currently c7-c8.
They may look the same, but they are actually very slightly different... but I can't solve the second puzzle, so I think it may be broken... EDIT: The link is now fixed.
The only problem I have with all this is how to tell, of the two configurations, which is the correct one. You go on and on that it could be either, so how can you just decide one and go with it? Is this just a shortcut to the end state where, if you used logic thereafter, you would find a conflict? You guys made it sound like pick one and finish the puzzle with it, but either is fine.
To get at why they can do that, go back a sec to thinking about it in Sudoku terms. If you found a rectangle where you had three corners that were only able to be 1 or 2, and the fourth corner could be 1, 2, or 3, then to avoid the Unique Rectangle you would have to put a 3 in that last corner. The takeaway here is that some of the corners of the rectangle are more "locked in" than others. It's a bit more difficult to see when it comes to Star Battle, but the same idea remains. In some cases, only one corner is possible to remove, so it MUST be that one. To help solidify this explanation, watch again at 15:04 and pay attention to the bottom-left corner of the Unique Rectangle he's showing off. This corner is our 1/2/3, because (and I hope I say this properly) it is the only one of the four that can be ruled out by a star elsewhere in the puzzle. As Simon says, without a star in one of those two squares below our bottom-left corner, it's still a uniqueness problem even if you DO just "decide" the order for yourself. Those outside stars HAVE to be there to break the rectangle up. That's what Kurt is looking for and finding so quickly: the corners that are "locked in" and can't be ruled out, and the one weak corner that still can be. I hope that helps. I do tend to ramble...
I don't understand how it is okay to use uniqueness as a tool to solve a puzzle like this. What if the puzzle doesn't have a unique solution? By assuming uniqueness you may be ruling out other legitimate solutions. My understanding is that these puzzles are supposed to have unique solutions but what if the setter made a mistake and there were multiple solutions? Surely you would miss it if using this technique in your solve. Would it be fair to say that generally people don't talk about this as a tool for solving because it's not 100% reliable? I would be very grateful for some education in this matter. It feels more like a cheat to me than anything else.
This video made me just absolutely mad. I couldn't get the idea about swapping however much I tried to figure it out =( At 9:00 it just looks very much like forced solution. I found out there couldn't be star in r10c3 or r10c4 by placing them there and going forward and braking the puzzle. However I couldn't figure the right side of the bottom two rows however I tried to do it =/
I don't understand it (It has ne lost) (Oh look^, I can't even type straight, lol) Cool though (I guess.!? Lol) Cheers though 😮😅😎☕🎶 [[ I guess I'm looking for a solution within seconds and not for a drawn-out logic trail. Good job. Cheers again ☕😎🎶 ]]
I see with you guys coming from speed puzzling but as a mathematician I strongly believe that using tuniqueness for a solve is like prooving a theorem by writing "and here some magic happens" in the middle. Also I have never seen a puzzle where it was necessary to use uniqueness, so you are robbing yourself of all the fun.
man i ramble so much in that video.. you guys are much more eloquent haha.. anyways, as always, cheers! 😊
EDIT: originally this was just a video to simon/mark to share this trick so my explanations aren't as in depth, my apologies, i think i would have explained things differently otherwise :)
Thank you so much for pushing the boundaries of puzzle theory. It's always delightful when a new trick is discovered!
Fantastic job, Kurt. I really appreciate this.
Is that KURT HIMSELF?!?
Started watching your music videos, then baking some nerdy nummies, then playing chess against the try guys... you are everywhere! Great logic here, thanks for the tips
You and our friends who run this channel are certainly far better at this sort of thing than I could be, but: whenever I see incredible times on software games, I wonder about cheating. In particular, could it be there is other software spamming the puzzle site? (Also, when the puzzles are generated randomly and the leaderboard is for all puzzles, there's the possibility of ridiculously easy ones coming up randomly for some users and not others; I've seen this on a minesweeper web version once.)
"He said it took him 26 hours to solve it."
Oooooooh man I wanna see you do that one ;)
might take him an hour
As far as I know, that 7 Star starbattle is only solved by 2 people so far, me and Takuma (from Castle Wall vid). Can you be the third?
EP Link?
@@kamikazegargoyle here, on twitter
twitter.com/ark184/status/1144547648445173760
@@ep1873 ありがとうございます〜
This was 47 minutes of pure confusion for me. I'd never even heard of Star Battles before this video. Still, it's incredibly satisfying to see you solve such extreme puzzles!
I'm still trying to understand how th you put the first stars in
@@thesphnx6836 The kings move thing is pretty helpful for easier puzzles.
I’d watch a 26 hour video of you solving the 7 star starbattle
Live streaming it would be even better!
...in one go
I would totally watch such a video. Would take a week, but how good a week that would be
TH-cam recommended one of your Sudoku videos to me & now I'm binging your channel.
I'm a total puzzle noob, but you really awake my interest in them!
Great work!.
I would genuinely be scared if Kurt started doing competitive puzzling... he's lost me twice already!
Hmm - I've solved a *lot* of all kinds of logic puzzles, and uniqueness is something that you can use in any of them. I can't say I'd thought of it as being particularly prevalent in Star Battle though - interesting!
I was not expecting to hear the words aardvark eyes today.
26 hours to solve, eh? Now there's a livestream idea and I'm sure we'd all watch every second of it
Thanks to this star battles are my new addiction. Also, I loved the excitement in your voice when giving the aardvark eyes
Cinderella Girls fan here with some interesting notes on the puzzle theming. For the 3-Star Mio puzzle, there's a character named Mio Honda whose theme song is called "Mitsuboshi", which literally translates to "three stars".
On the 7-Star puzzle, "Abe Nana is forever 17" is a recurring joke for the character of Abe Nana, and "nana" means 7 in Japanese.
Around 37:40 it’s interesting how he goes into a lot more complicated logic when rows 3 and 5 already have two stars in each and a domino forcing a third star into them, meaning he can X off the entirety of the remainder of the rows.
This trick is actually so awesome, it took me a while to properly understand it and get better at spotting it. I've been playing 8x8 hard puzzles and it more than halved my time.
41:25 actually, it is helpful. It's the uniqueness thing KHS was talking about. You need 2 more stars in row 15, and if they're NOT in both columns 11 and 15, then the two stars in rows 14-15 and columns 11 & 15 would be swappable. So, they both have to be in columns 11 and 15, forcing our third and final star into row 14 column 13.
good catch
"he didnt have to label all the shapes with animals"
i mean... uh. yeah ^^
I have actually thought about this very point as I solved star battle puzzles before! But I never realised the full implications of uniqueness in star battle, like Kurt showed during his live solve of that puzzle with the interaction of the two cells below the P-pentomino shaped region. How nice! It really feels like there's a bunch of star battle logic out there that's just begging to be discovered.
Love star battles! Love Cracking the Cryptic, especially during this lockdown.
I never knew this kind of puzzle was called a starbattle. I only knew it from an app I stumbled upon some time ago. It’s called Alberi and instead of stars you have to place trees. Now I’m really excited to get some more tips for solving the puzzles 😊
Those interjections really helped, I do understand the uniqueness thing as technique now. The things Kurt was pointing out went completely over my head however, and I have a feeling it's because of how new I still am to star battles lol
I really liked that you linked to the easier puzzles, they were a treat!
This tutorial was very good. Learned many new techniques in this video. Thanks for it.
I got it!! I'm not even going to bother with the time because it took me about 2 hours. First time ever doing starbattles but the way of solving it was awesome! I ended up using linear equations to solve some parts too.
Spotting a move before simon does makes me feel so smart and frustrated at the same time lol (both feeling usually dont last very long)
At 7:55, how does Kurt conclude there must be a star there? Couldn't both stars in that bottom right box be in the second last row and both stars in the bottom left box be in the bottom row (both of Simon's red highlights)? The greyed out boxes due to uniqueness make sense, but I'm missing something to place that star.
At 7:13 he says why, though he doesn't really explain it fully.
The reason he says "you have to put a star down here otherwise there's not enough space" is because in 2 columns you need to place 4 stars. If there is no star in that bottom shape for those 2 columns, you need to place 4 stars in the empty spaces above it. There is going to be 1 star in the shape above (the one with only 2 white spaces left). That leaves the remaining 8 spaces above, which forms two 2x2 squares. You can only place 1 star in a 2x2 square since once you do it touches the other 3 squares, therefore the two 2x2 squares can only house 2 stars.
So there are 2 stars in the top 8 squares, 1 star in the domino he has marked on row 7, so the 4th star MUST be in one of those 4 squares in the bottom shape. That means only 1 of the dominoes at the bottom of the bottom left shape can have a star, not both. Since placing a star in one of those 4 spaces allows you to swap it between the top and the bottom of those 4 spaces, the star in the bottom right shape must not be swappable. The only space in the bottom right shape that isn't swappable is the square he marks at 7:55. The other 6 can be swapped up and down.
Would have been nice if the M, I and O had been de-highlighted (or if there had been an option to uncolor them) in the last puzzle. Quite confusing trying to color-code the grid into stars/non-stars while a bunch of cells are already colored.
Kurt's uniqueness point would've helped sort out the stars in the bottom right dominoes @ 44:10!
Could you imagine solving this by streaming. You'd have so many people shouting at you 😂😂 or any puzzle for that matter
Wow... within the last two days this channel's sub number has grown by about 40%. That's just crazy!.. I'm so happy about that!😆
6:48 wow. that guy just did in 2s things that took me ages to figure out
8:11 thanks
So, what makes uniqueness a great thing in star battle and frowned upon in sudoku? (honest question, I'd like to know what is different about these puzzles)...
It's more of a speed solving tactic
The puzzle in the video is slightly different than the puzzle in the link. Specifically, the cell he designates as a star from uniqueness is in the other shape in the link!
can someone help me find the 7 star starbattle teased in this video @ 17:37 ?
twitter.com/ark184/status/1144547648445173760?s=19
Maybe that's an unpopular opinion, but I think uniqueness IS cheating. It is a shortcut that will get you through the puzzle faster, at the cost of verifying that it is a valid puzzle in the first place. If all you go for is speed, thats fine and you should absolutely use it. But if you solve a handcrafted puzzle without time pressure, you are taking away some of the fun for yourself by circumventing the logic that was put there by an author. And in a good puzzle, a fully logical path will be there to be found.
While uniqueness arguments are interesting, they are a form of Metalogic and should never be confused with or viewed in the same category as normal logical steps.
I was thinking the exact same thing.
Why would it be ok to use uniqueness in a star battle puzzle but not sudoku? I don't get it.
I think that trick is meant more for speed solving
Very interesting video. I'm not certain your explanation during your second interjection was 100% clear if someone didn't already follow, so I'll have a go at explaining it in a slightly different way:
When you use a uniqueness trick find a particular solution that you know must be correct, you also know that there must still be something in the correct solution that FORCES it to be correct. And therefore, you should look to see what other features of the puzzle could force the solution you found through the trick. Often, there will only be one or two squares that, if they were stars, would force the solution you know is correct, and so you get even more restriction from the initial uniqueness trick.
I kind of get why the 2 positions at 7:25 are not possible, but why can you rule out the 3 on the bottom right? I don't really get that, can anyone explain ?
Never heard of Star Battles before but I was sending my thoughts really strongly that you would see the four red dominoes on the left. The top domino couldn't have a star in it's left hand side due to the shape below it. You got there eventually but it was sticking out to me like a red domino. The pain of watching puzzle solving, hah!
GAH! I'm still not following some of the uniqueness logic. Simon, would it be possible to do a star battle without using uniqueness then do it again with uniqueness?
Kurt's second puzzle, 3rd column from the left, bottom row... I see a difference between the puzzle in the video and the puzzle in the link.
Never thought I would see Idolmaster in a puzzle
"There you go, aardvark eyes." - Simon 2020
Great Video! The uniqueness problem is really interesting.
You could have used it to figure out row 4 and 6 much sooner because of uniqueness in the red dominoes in column 2 and 3.
I just feel totally lost. I dont understand either of those explanations. From the start it was okay, uniqueness... this cant be star, because you can do it the other way... but then in a next second... you cant do this, it must be the other way, then I got lost.
ya im confused too how do they determine which is the correct way. I don't understand what makes one unique and not the other?
Its really simple actaully if you just listen to what is he saying
I am glad I am not the only one who felt he had to pause every second of Kurt's part as he didn't explain 95% of what he was doing...
Its hard to wrap your head around. The way I understand it in the simplest form, if you have the right setup (two parallel sets of two-squares and the squares around them can't be stars), then in the solution the two stars must be on the same row, because if they were alternating then you could switch it. By being on the same row the stars force the other parts of the puzzle to be solved
I had to watch it a couple times to understand as well 🤯🤯
Can anyone explain 9:46 more.. I understand it is not unique when placing a star in r10c3 or r10c4, but doesn't it works the same while placing a star in r9c3 or r9c4? I don't see why only r10c3 and r10c4 cannot be a star but r9c3 and r9c4 can...
I dont get it
out of all the places i'd never thought i would see a CG reference on this channel xD well shows how far japanese popculture has permeated ;)
There's a fair share of people in the intersection between CG Ps and Japanese puzzle setters, me included :)
I remember when these puzzles were in the New York Times Puzzle Mania 2019. If you would like to solve Starbattle (Two Not Touch as NYT calls it) Monday-Saturday in print.
i thing is I've heard the term uniqueness on this channel from Simon and it was always the line "i'm not going to use uniqueness to solve this" so hearing Kurt claiming to have never seen or heard of this technique being used confused me
So to give a possibly useless answer, I have indeed noticed the uniqueness possibility with star battles but have mostly just chosen to ignore it in favor of solving them in a more intended path. The trick is cool though! I definitely rely on uniqueness if I intend to solve a puzzle of any kind quickly(ish)
I don’t get the logic at 7:55. I get why the middle of the three cells he grays out can’t have a star, but why are all three precluded from having a star?
Oooooooooh. For the same reason. If either of those two other cells has a star, then we can just move things around *within the same block* and it’s not unique.
I'm a bit surprised at the "not cheating" comment, since I thought you've mentioned in previous videos that you don't like using uniqueness constraints in solves because they feel a bit cheaty.
will there be away to play this and other puzzle sudokus in one of your apps?
"...and again, sorry if this is obvious to all of you..."
I didn't even fully understand your trick yet! *sobs in stupid*
47:18: "so this has to be a star" -- any particular reason?
I think a more interesting idea would be to explain how he ruled out so many squares to begin with. The top left is obvious (as there must be two in top right) but the next 6 rows !?
20:00 ‚We‘ve got an elephant shape here, that‘s what that one looks like.‘
That‘s the only thing I noticed as well about this puzzle 😂
An interesting puzzle type I had never heard of before, and a cute/nifty trick for solving them for sure (at least I believe I understand the basics since "uniqueness is required for a solution, so any options which result in the puzzle being solved in two or more ways you can be sure is not true/rule out as possible." That at least goes back to the puzzle logic I do know for Sudoku which has the same principal in terms of "you did something wrong if two number pairs can flip-flop around and the puzzle is still solved.".
That said, I have absolutely no idea what star battles beyond the very basics spelled out here and my general ability to understand it. What I and I assume most people who are completely unfamiliar with the concept until this video (which has got to be a lot of us because of the glut of new subscribers to this great channel) then the very fundamentals of a star-battle concept are lacking.
The kinda stuff people who are familiar with the puzzle type would totally take for granted results in, say, watch Kurt start solving one of the blank puzzles. He immediately seems to figure out "must be a star here." But..why? I'm sure he is right, but I have no clue as to why.
I assume somewhere online or perhaps on this very channel there is a "The basic solution solving techniques for star battle puzzles 101", if so it'd be great to include that in the video description for those of us who would like to follow along but are simply ignorant of some basic understands of solution/solving techniques and their underlying logic.
when discussing the fact that there must be a star in r3 c4/5. Why is that? That assumes solution has two stars in c8 c10 in different rows. And uniqueness alone forbids that (in that case one could simply swap those two pairs around just like he later shows with reasoning for bottoms of c1&3). So solution with star in r2c5 is impossible to start with
boy am i glad im subscribed
Let me guess, you've spent a lot of time with your kids lately. Elephants trunk, duck shape, aardvark eyes, ... I love it.
The first two links in the description send us to the same puzzle.
With one square difference at the bottom of the puzzle
It should be fixed now.
@@CrackingTheCryptic there is still the issue with the one square difference in the bottom row
I have used this thinking in a path game called Maysu I think is the name. Often if I test a direction for a path it gives more than one way to continue the path so I know that the test must be wrong.
2nd puzzle linked in the description is not the same as the video. there is a different border in the bottom row
Hmmm, completed the first with a little difficulty. The third flowed really quickly and smoothly. The second I thought I had it, then realized I had a mistake, so I need to retry later. I'll hit #4 later on.
Bottom row of puzzle 2 on penpa link is not correct. The line should be drawn between cells 6 and 7, not between 7 and 8.
I knew there had to be another technique I was missing to solve these, I was always getting stuck looking for a logical path and put it down to low quality puzzles.
what is the link for the 7 star puzzle
Maybe I'm not understanding properly. So there's a pair of dominoes on the grid which must contain 1 star each, and thus the stars' positions can swap interchangeably. And somehow by considering uniqueness they're able to realize which of those positions is valid? I don't follow the logic there. No matter what solution they end up with, if there's another arrangement of stars that fulfills the rules of star placement, surely that means their solution is non-unique as well?
11:05 why there should have a star always... sorry I cant keep up with kurt's logic
It took me a while too. Look at column 9. If you place a star in R1C9, then it forces stars into R3C8 & R6C8. If you place a star into R7C9, then it forces stars into R1C8 & R6C8. Either way a star will go into R6C8.
@kvckelvin7 I was wondering the same thing. But if you put a star there (say R2C6), it blocks two squares from the shape right below it and forces its stars to at the ends of the remaining "Z" (i.e. R5C4, R4C6). At this point you would have tree stars on the same column (C6).
"Kurt's second puzzle" link takes you to a puzzle that is slightly different. The box in the bottom right is missing a square. I think that slightly different puzzle doesn't work.
Opened TH-cam and see this uploaded 16 seconds ago :)
I'll be honest and say that in the puzzle that starts at 6:33 I still don't follow the logic of this uniqueness property, even after both KHS and your explanations.
I didn't either. Especially since I quite literally never heard of a star battle puzzle, it would have been nicer to actually see what a star battle was before trying to go into an advanced strategy for speed solving them
When determining the 4 dominos in c2c3 you completely forgot about the topic of this video: Uniqueness.
You had only 1 star left in c4 to force 2 stars into c2, so this star must touch 2 of the dominos, wherefore ou could immediately have Xed out r3c4 and r5c4 as here the star would only affect one of the doninos.
r10c7 is wrong in the link, in vid its part of the right hand shape, in the link its in the left shape
Should be fixed now.
A bit unfortunate they went so in depth on KHS's new (?) trick and proceeded to never use it in Simons solve. There were at least 2 times it would have been very useful (and surely way more that my novice eyes didn't spot).
Simon, the second puzzle is different than shown in the very bottom row. The line is in a different spot.
Should be fixed now.
honestly, i get the filling up the spaces but the logic behind the areas and hypothetical lines is lost on me. Could you do a smaller/simpler puzzle or a tutorial on space battle puzzles altogether?
He has made easier ones on this channel already. I also had a hard time following his explanations on this puzzle as well.
It's kind of funny, I came up with the Uniqueness method on one or two pencil puzzles on my own some time back…
Uniqueness is by far a better name for it than my “Proof by Provability”
Second puzzle linked is broken. in row10, the bottom right object need at least 4 spaces, so the division should be betwen r10c6 - r10c7. instead of currently c7-c8.
Should be fixed now.
two idolmaster puzzles? and they are two of the best star battle puzzles of all time? wow
5:43 Jesus, that WAS fast
Some people just process information at light speed. I know a guy from university who solves sudokus faster than he can write the numbers in.
this guy's brain works at light speed
@@bowlchamps37 To be fair, it's also not a live solve; he's narrating how he's already figured out how to solve it.
yea it isn't live :) the solve at 11:55 was the only live solve, the ones before were just puzzles i thought showed the trick well!
Simon, the 1st and 2nd puzzles are the same!
They may look the same, but they are actually very slightly different... but I can't solve the second puzzle, so I think it may be broken... EDIT: The link is now fixed.
kurt's second puzzle in the links is broken, the walls are in incorrect places. r10c7 belongs to the other shape
Should be fixed now.
@@CrackingTheCryptic thank you very much!
the bottom row in kurt's second puzzle is broken. The line is in the wrong place
The only problem I have with all this is how to tell, of the two configurations, which is the correct one. You go on and on that it could be either, so how can you just decide one and go with it? Is this just a shortcut to the end state where, if you used logic thereafter, you would find a conflict? You guys made it sound like pick one and finish the puzzle with it, but either is fine.
To get at why they can do that, go back a sec to thinking about it in Sudoku terms. If you found a rectangle where you had three corners that were only able to be 1 or 2, and the fourth corner could be 1, 2, or 3, then to avoid the Unique Rectangle you would have to put a 3 in that last corner. The takeaway here is that some of the corners of the rectangle are more "locked in" than others. It's a bit more difficult to see when it comes to Star Battle, but the same idea remains. In some cases, only one corner is possible to remove, so it MUST be that one. To help solidify this explanation, watch again at 15:04 and pay attention to the bottom-left corner of the Unique Rectangle he's showing off. This corner is our 1/2/3, because (and I hope I say this properly) it is the only one of the four that can be ruled out by a star elsewhere in the puzzle. As Simon says, without a star in one of those two squares below our bottom-left corner, it's still a uniqueness problem even if you DO just "decide" the order for yourself. Those outside stars HAVE to be there to break the rectangle up. That's what Kurt is looking for and finding so quickly: the corners that are "locked in" and can't be ruled out, and the one weak corner that still can be.
I hope that helps. I do tend to ramble...
I would absolutely watch this for 26 hours
Kurt Hugo- wait. I know that name. ! No way, that's incredible.
Example 1 was obvious to me, example 2 wasn't. I dont like uniqueness though and dont care about speed, so its not that useful to me.
The first and second puzzle links in the description link to the same puzzle
I don't understand how it is okay to use uniqueness as a tool to solve a puzzle like this. What if the puzzle doesn't have a unique solution? By assuming uniqueness you may be ruling out other legitimate solutions. My understanding is that these puzzles are supposed to have unique solutions but what if the setter made a mistake and there were multiple solutions? Surely you would miss it if using this technique in your solve. Would it be fair to say that generally people don't talk about this as a tool for solving because it's not 100% reliable? I would be very grateful for some education in this matter. It feels more like a cheat to me than anything else.
I would snap Cracking the Cryptic's hand off cor a star battle app
omg I know who that is, I've seen him on TH-cam singing and playing the piano. I had no idea that he did these.
"aardvark eyes" Isn't that a song by Eric Carmen?
The first 2 links are the same puzzle, with 1 border moved
Should be fixed now.
This video made me just absolutely mad. I couldn't get the idea about swapping however much I tried to figure it out =( At 9:00 it just looks very much like forced solution. I found out there couldn't be star in r10c3 or r10c4 by placing them there and going forward and braking the puzzle. However I couldn't figure the right side of the bottom two rows however I tried to do it =/
I really want to see the 7 star puzzle that took 26 hrs !
I don't understand it
(It has ne lost)
(Oh look^, I can't even type straight, lol)
Cool though
(I guess.!? Lol)
Cheers though
😮😅😎☕🎶
[[ I guess I'm looking for a solution within seconds and not for a drawn-out logic trail. Good job. Cheers again ☕😎🎶 ]]
You were looking at column 9 for ages.
Who wants to see the 26 hour one
I see with you guys coming from speed puzzling but as a mathematician I strongly believe that using tuniqueness for a solve is like prooving a theorem by writing "and here some magic happens" in the middle. Also I have never seen a puzzle where it was necessary to use uniqueness, so you are robbing yourself of all the fun.