“You must have a go at this yourself”, stares blankly for 5 minutes and watched video. Excellent puzzle, excellent solve and videos like this is why I watch this excellent channel

23 minutes, but that's after learning off of your starting logic. Super interesting. Thanks for sharing.

Have you ever played a puzzle that is not "ABSOLUTELY beautiful?" :-)

Really enjoyed it. I couldn't start without your observation about having an empty 2x2 box in each row and column, 3 of which in the central 2 shapes

What an incredible break-in! Missed it completely when I first solved it in my toketa book (vol.7). Unfortunately, star battle will always be extremely prone to bifurcation. With hard puzzles, it is almost always faster to bifurcate than to look for the logic. However, I normally re-solve star battles if I used bifurcation the first time, in order to reveal the setter’s true intentions.

Today is the day that I learned I am not cut out for star battle puzzles. I spent 20 minutes staring at the grid and going nowhere, tried to use geometry but couldn't see the forest for the trees other than the 2x2 block in the top right. After watching the break in by you (and being completely dumbfounded), It still took me 40 minutes to solve because I kept confusing myself with my 2x2 notations and failing to see box logic. As nice as this puzzle was (and I loved the video overall), I'm miles away from being as proficient here as I am with any of the sudoku variants you've shown on the channel.

I broke in to the puzzle using standard geometry. If you notice the peculiar shapes in the middle, and isolate columns 3-7, you can identify that each of the 8 2x2 areas outside of the center 2 shapes must contain a star to get to the total count of 12 stars required for those columns. The same is true for the rows 3-7. Then using the knowledge that a star must occur in the top-right most 2x2 corner, you can exclude stars from the bottom-right and top-left 2x2 corners (using basic geometry). This requires a star must exist in the bottom-left 2x2 area by the same logic. Similar to what you showed, but does not require recognition that 5 2x2 areas do not contain stars.

Let's stop for a moment and appreciate the fact that he spent half of the video explaining how the puzzle works, and then solved it in under 15 minutes.

the first time in a looooooong while that i'm watching one of these videos and wondering what on Earth is going on! 😂

Fully agree on it being divinely beautiful in it's construction. One can for ages blankly stare at the grid looking for even a single cell to pick off at the beginning, yet every region is just one or two tiles too big to be able to be restricted enough. Likewise with the way the regions intersect making slicing the board almost impossible. A truly devious layout that at first glace looks like it has an easy way in yet very quickly proves otherwise! The two-by-two checkerboard lining up with the central two regions is just stunningly elegant and so well hidden, but once seen (or, more appropriately, pointed out) and understood the cascading solve is poetry. The only small amount of bifurcation I did was to briefly see if there was any pattern or relationship between a couple of the unresolved outer pairs on diagonal opposite sides of the centre, but quickly discarded it when I spotted a little extra logic in the centre. Given that the centre grid only had three possible variations for which could be the three blank sections, it was quite easy to rule out the odd corner cells that cut into the opposing region (in the interlocking part of the central regions). If one was to be used, the other would also in order to achieve 2 stars in each region, but then the stars would be diagonally touching, so in effect neither could be used and all those cells could be ruled out.

Before watching I was able to mark exactly one thing on the grid. Row 9 column 2 can't contain a star because then there wouldn't be room for 2 stars in the shape to the left. Amazing logic you present here.

Its allways the same with the puzzles you show: 1. I stare at it w/o a clue, 2. I see what you do and understand and can pretty much finish it 3. I see the result and realize I made a mistake in the last few moves. Its like calculus all over again, but fun^^

Spent about 20 minutes looking at it, deduced a few small areas that had to contain a star, was not able to arrive at the conclusion you came up with. Amazing solve, very cool logic.

22:35, at that point you can eliminate the sideways T shape from the bottom of the big region in center right. Because you already have 2 2x1 regions with a star each in it. That cracks the thing wide open.

i've done 900 of these puzzles in an app and i had discovered all the tricks you showed - except for dividing the whole 10x10 grid into 2x2 areas. thank you!!

Clever puzzle, but not one which I'd want to work with on a frequent basis.

It's really a nice puzzle. I watched your first minutes going through the first logical thoughts and then started doing the puzzle myself. And it doesnt help at all if you know a star position because you have to understand why and go through all thoughts yourself again. I even had to restart. And if you turn the puzzle by 90° and do it tomorrow it's still as hard as the first time :)

I’ve seen puzzles like this called parks. There is a whole app dedicated to them. It starts with one tree (in this case) per row/column/region but it goes to 2 per later.

I think you did not explain the logic at 22:35 you can only say that also in the third blue purple pair is exactly one star after you eliminated a star from row 6 column 8 because of the two pairs of forced ones in the right shape of the middle block

Dunno how long it took, but I got this solve with help for the break in from the video. I play these types of puzzles sometimes, but on a randomly generated site, and just kind of brute for it. Hadn't don't a puzzle like these where the brute for just didn't work, but there is some neat logic to get you started.

I think the region checkerboarding caused you to overlook many easier paths to placing stars. There were many times through the solve where an area was confirmed to not have star due to isolating the two starts in a row/column/area. You kept going back to evaluating what 2x2 region could or could not have a start, ignoring easier deductions about the middle areas or rows. Good solve regardless, I had no hope of starting this puzzle with the insight.

Took me about a hour, no bifurcation, and got a completely different jump off point, but I am still quite happy, as the ending was quite similar to yours !

Simon is the only person who would use green to indicate “don’t put anything here”, purple to indicate a snake, and colors other than green and blue to indicate islands and ocean.

I didn’t have to use your trick. I used your third technique often two uses of that technique at once in a short chain. It took me quite a while to solve it. More than an hour. But of course most of these puzzles on your channel take me over an hour. I’m just glad I can get them solved.

I solved without the 2x2 insight; I got stuck in an apparent contradiction (never figured out what it was), so I went to finish the video and was amazed by the opening. After watching, I went back to my solve and still reached the solution without the insight. Had I not gone back to the video, I surely would have managed to finish without knowing in the slightest that the opening existed. Amazing how easy it would've been to miss this strategy.

That solve is so beautifully elegant. I love it. Mine used the geometry the same way, not elegant though, more just a realization that the central area was really big to only have four stars, and so that would make the sides and top quite crowded. You realize you just can't fit more than four stars on the left side of the middle area; having to have four on the right yields the same deductions as in this video if not necessarily in the same order. I wound up really enjoying the puzzle and glad I walked away for a while instead of giving up.

12:00 ok this is the perfect puzzle and I knew nothing about puzzles before this channel

Thank you so much for sharing this amazing puzzle. I had no idea how to solve it. Once you gave the trick of the 2x2 squares then it all became clearer.

These star rules are surprisingly similar to how stars work in the witness, all in pairs and such

I'm definitely going to add this sort of global constraint to my armoury now, though I've only seen this puzzle here. It took me over thirty minutes and i did use bifurcation but it was interesting to see that many of the same 2x1 areas appearing while I was solving it. My process started the same way, with the top right hand area and with the top two rows but I then looked at the rightmost two columns. Since the top 2x2 square contained exactly one square, I tried the case where row 4 columns 7 & 8 contained no stars. That put two stars in right two columns in the shape at the middle right. In turn, that put only one star in the rightmost columns for the bottom two L shaped pieces, which meant three were in the bottom tow rows between columns 4 & 8, which put a star in row 10 column 4 and the same sort of 'stripe' effect you got. The rest (slowly) followed from there. Had I reached a contradiction, at least i would have known the R4C7,8 contained a star with all the restrictions on the row above & below that this entailed.

Wow! I feel i only understand this logic 20%. Very new logic for me, I feel so confused,, even when I listen to you explaining it, sometimes things click and other times I am like hmmmmm??? Thanks for the interesting video!

"hmm, very intriguing. Colours, and lines, and stuff. Very intriguing indeed. Puzzle? What puzzle? No, I didn't solve any puzzle, but look how colourful this shit is. Love it!" - my response when asked if I was able to solve this puzzle

Took me about 35 minutes but I had to use brute force(basically spent 15 minutes proving to myself logically that there was no star in first column second row) to start the puzzle and after watching the video I was amazed with the 10x10 logic. I am definitely going to keep that trick in the back of my mind.

At 22:50, I saw there were only 4 open spaces grouped into pairs in one of the central regions, so the purple+blue area in row 6 has to contain one of the stars in columns 4 and 5. Another star has to be in row 4 of columns 4 and 5 and there are 2 known stars at r2c5 and r10c4, which forces a star at r8c6 and breaks the rest of the puzzle open.

Me: wakes up in the middle of the night and cannot go back to sleep, thinks “see if Simon has a new puzzle.” Me 27 minutes 6 seconds later: cannot go back to sleep, has a tiny headache and feels dumb as a box of rocks :-)

Have you ever considered using an eye tracker? I think it would be very interesting not only to hear you think aloud as you solve, but to see where your eyes go, and see the ways you scan the grid when you find cheeky tricks.

Would have had no chance without watching you do the 2x2 boxes and explain 1 must be missing from each R/C. After that it was very fun puzzle!

What fascinates me about the harder puzzles is there is always only one way in. Once that way is found, there is one way to proceed. Whenever I get stuck, I just fast forward the video to the exact state I found myself in to learn the next step. The only time the video takes a different path from me is when I've made a false assumption and headed for a contradiction.

Wow! This is true of all 10x10 two-star puzzles. 25 squares, 20 occupied, 5 free, one in each row. The next biggest example would be 14x14 with three stars per region. This has 49 squares, and 42 squares, and again the 7 squares with a star must be on different rows and columns, because each pair of rows or columns needs six stars. This will be useful knowledge! In general, if the grid dimensions are even (so that we can divide it perfectly into 2x2 squares), we can say 2n x 2n, the number of regions is n². And with that, and p stars in each row, column, and shape, the total number of stars is 2np. So this works if 2p is exactly one less than n (or in other words, if double the number of stars per row, column, and shape, is exactly one less than the total number of rows, columns, or shapes). Amazing stuff!

32:00 such a weird puzzle... i tryed to find boxes that arent a star! after i found 3 i tryed the 4th one. but by guessing thats the box is a star i got the right solution... didnt get one single star placed other wise

What a beautiful puzzle! Would like to see other star battle puzzles like this😉

Short version: If you divide the grids into 2x2 blocks, there are 5 blocks on each row/column Each row/column of blocks contains 5 blocks and 4 stars, therefore there is an empty box on each row/column, so if you find one on any row/column then you know for certain that no other block on that row/column is empty

11:15, I got it eventually, but I don't thik you fully explained your logic. I had to fill in an important gap which took me a minute.

Great video, but I think your first 10 minutes demonstrates pretty convincingly why this kind of puzzle will never catch on. Hardly anyone is going to stick with a puzzle for so long without being able to make a single move.... Star puzzles need to come up with a way to get into them faster.

ive never solved a puzzle correctly and then watched a solve that made me realize i did it completely wrong

I shall use this expert techniuque you have taught us from now on. Amazing puzzle, very fun!

22:34 I think you got lucky here. It looks like you goofed up the logic, since those two spaces don't necessarily contain a star - at least, not with any logic that you presented.

I think that it was around the 10m30s mark that you began to sound like Charlie Brown's maths teacher to me. I could hear the voice, but less and less it made sense to me. I can see that it all worked, I could see the 4x4 boxes and the ones that were blank, but to how you begin to make the decisions about where the stars have to go... no clue. It's really interesting watching you solve and hearing the logical reasoning behind it, even if you lost me minutes earlier.

Brilliant and beautiful. More please.

Just found you 404 page. Awesome. I got 4 stars right grrrr

That's beautiful! I never would have seen that on my own.

Super interesting video !

11:18, you said of those two, exactly one must not have a star. This logic is not clicking for me. I could easily place stars so that only the middle three 2x2s are without stars.

Lovely puzzle solve.

Can someone explain to me what Simon meant at 23:01, starting with "And if we look..."? I don't understand why he says that either one of the two purple squares or one of the three blue squares must be a star, but not both.

That cell at r9c2 could've been ruled out since the beginning, since if it had been a star, then the L-shape at the bottom left corner would break since the only two remaining spots would be neighbors

At 22:34, the logic seems to have to be the shape containing 2 stars. I thought you were looking at rows or 2x2 blocks and got confused

16 minutes after your initial logic. Without that logic I'd have been nowhere! That said, given I've never attempted this style of puzzle before, I'm not sure it could be the 'perfect puzzle', so to speak. It must have been quite straightforward apart from that 1 piece of initial logic for _me_ to solve it so quickly. For me the perfect puzzle needs more than just one moment of inspiration.

I dont get it

22:36 you can't make that deduction from that point. From what you know at that moment, both stars could be in the right three cells. However, you can note that the center-right shape does have two places that definitely have stars, so you can eliminate the rest as possibilities. This brings you to a point where that logic does apply, and everything can proceed as you demonstrate.

holy shit.. i usually suck at star battle... with simons starter tips i finished before the 20 minutes on the video

please more star battle videos :)

Brilliant !

Isnt the conclusion at 22:38 a bit rushed as there can still be a star in the other purple square on the line? Due to the shape it's still correct tho. But maybe I'm just missing something that makes it even more obvious

Yes!! Somehow I managed to solve this without help. My brain hurts!!

First star battle. Thanks for a brilliant puzzle, but not so much for keeping me from doing my job! I need to stop loading youtube! Had to watch the first 10 minutes to learn the basics of star battle, but was able to complete it eventually, though it was with a lot of "if this is a star what will happen... Nope, contradiction, try again." Now I'm watching your video and your colors are opposite mine and confusing me! I colored the outer 2x2s as alternating green and yellow, then gray was my notation for no star. I did choose red to mark a star, so that is the same.

18:45 Kinda surprised he doesn’t realize that there’s only two locations possible for stars in that bottom left shape.

Wonderful

Great puzzle! 51 minutes unassisted - logic only (no bifurcation).

Parks Seasons - Logic Games (iOS, don’t know if it’s on any other) has hundreds of these kinds of puzzles, if anyone wants to solve more Though far from as elegant as this

I noticed the shape in the middle but I couldn't figure out how to use it. So after 10 minutes of fiddling with it, I gave up and went for a more brute force method of solving the puzzle.

This took me 3 hours to solve , then i watched the first few minutes of the video and was like oooh ... yes this only took me 2,5 hours to figure out ....

48:50

It's clever but... it's too clever. I think a really terrific puzzle has easy gimmies at the start, and reveals its secrets as you work through it. This seems to require such a brutal level of analysis in different dimensions before you can even put down one thing for sure!

I want to love Star Battle but I can never find good puzzles, especially at my skill level (beginner).

I don't think I would ever have broken into that puzzle. How long did it take you to find that?

That. Took me. An hour. But it was my first star battle, so that could be why

I did green as a star and red as no star before watching the solution

Just curious, what does he mean by bifurcation?

How many times do you think he said the word “star”

Is artificial divisions not just a clever way of saying bifurcate?

Hello! I'm sorry, but I wont be having a try at this puzzle. I just got into Sudoku's through your channel because i found your app amazing! Since I'm a starter I would like to stick to one kind of puzzle. I know I'm not your average viewer, but i would really appreciate more Sudoku's instead of 'weird' puzzles. Yes, I know i can look up Sudoku's, but It wont have the explanation nor the website which I really love, however, a feature I would love to be added to the webpage would be that you can fill in already created sudoku's (without vid) and solve them through the app.

I would have definitely liked the video, but there was 666 likes and I really didn’t want to ruin that

What is bifurcation?

22:36 isn't that square elimination a bit of foul logic ? It isn't factually wrong, but the decision to eliminate that square is based on no logic at that point. There mustn't be a star in D6-E6 since they could've been in H6 and J6. Turns out H6 is not possible because of there already being 2 locked stars in central shape, but that wasn't ruled out at 22:36...

Oof. Made a logic fallacy, assumed that the 2x2's with no stars went diagonal from upper left to lower right, so I couldn't resolve the last two stars in C6 and 8 at the bottom. There was probably another glaring error elsewhere I missed. I do quite enjoy this puzzle, wish I had another!

Has anyone else been having a problem with opening the website?

@22:34 - "And now we get the same thing again". No we don't. At that point it is not true to say there must be one star in those two positions (row 6, columns 4 and 5) because there are still two other 2x2 blocks intersecting that row. It's only once we examine the large shape in the centre and eliminate one of those 2x2 blocks that we can say for certain there must be one star in those two cells. You got the right result, but your logic was flawed.

That's a square, not a star

i'd have liked to watch this video but a 14:44 minute ad without a skip button is far too much to ask.

Honestly your titles are cringy as hell. Why can't you just have them be normal? "Brilliant Star Battle puzzle by Maho Yokota" is it so difficult? You call every other puzzle "perfect" :P

First!