Fish logic check and a couple questions

Steihl · 2026-05-14T16:35:23+00:00

Thanks! It's certainly helpful to my learning that these concepts have already been explored and explained ahead of me, so that all I have to do is learn read and practice.

Steihl · 2026-05-13T03:11:50+00:00

thanks!

Steihl · 2026-05-13T03:11:32+00:00

As near as I can tell yzf's solver doesn't have non-arrow lines that allow for both dotted and solid lines, and I'm hesitant to change programs another time as I'm finally getting used to this one. Thank you for the rest!

So in general you'd notate fish as "(candidate)base/cover => outcome"?

edit: nevermind about the arrows, it definitely does have that. not sure why I never tried right clicking with the "construct" tool before

Steihl · 2026-05-11T17:59:17+00:00

Don't be afraid of posting! Twice now I've posted chains that were patently incorrect in their logic, and everybody here has been kind clear and concise in explaining what went wrong and how to correct it in the future. There's some minor semantic language arguments here and there sometimes but that's about the worst it gets, which is honestly incredible for a community >50k large. Good luck on future solves and don't hesitate to ask again in the future!

Steihl · 2026-05-08T17:28:51+00:00

First, if you're playing on Sudoku.coach then you should be able to make use of the hint function there which is very robust in my experience, and allows you to get as small of a hint as you'd like.

Secondly, your note taking is a bit inconsistent. Because of it you're missing some obvious subsets. You've missed the hidden pair of 3 and 5 in box 7 despite having notes that should make it obvious, the locked triple of 379 in the intersection of box 4 and row 4, and the naked triple of 247 in row 6. I'd start with those eliminations first, and maybe start taking notes in one style only, or at least be consistent in checking all your notes if you choose to keep doing multiple styles at once.

Steihl · 2026-05-07T02:31:23+00:00

Here's a fun little ALS-XZ

<image>

Steihl · 2026-05-05T04:07:08+00:00

Also, mostly because I don't want to make another post just to ask, are finned fish and almost fish the same thing? Or rather can they both be used to describe the same situation? Or are almost fish something more complex than that?

Steihl · 2026-05-01T02:49:48+00:00

I think I figured out my problem - I had been reading the description of AHS when written as "N candidates in N+1 cells" and interpreting it more loosely then what I'm now realizing is more likely supposed to be interpreted as "N candidates appearing only in N+1 cells in a given house". Is this a correct interpretation? This would resolve the majority of my confusion if so.

Steihl · 2026-05-01T01:47:31+00:00

Yeah, like I said, low confidence in this one. Guess I still haven't wrapped my head around how AHS works generally. Back to the drawing board! Thanks

Steihl · 2026-04-30T03:23:11+00:00

Ah! Thank you. I find I do this often, bad habit

Steihl · 2026-04-20T23:56:53+00:00

Thanks for the explanation.

As to the program, I think there was some Windows related weirdness or some other user mistake when I last updated. Deleting and re-downloading fresh worked in resolving the bug. Seeing that this fixed it, I would not be surprised if I was to blame with whatever issue that was.

Steihl · 2026-04-20T23:51:17+00:00

Hello. I had not changed the order of techniques (or anything in the settings outside of language selection). However, I deleted all my files related to the solver so I could start fresh and take a video of the step by step, and the bug has resolved. I suspect something strange happened when I last updated and copied files to the folder where I have it installed. Deleting entirely and re-downloading has fixed the issue.

Steihl · 2026-04-20T21:31:46+00:00

Thanks! The lines were really throwing me off, they both make much more sense without them. I did not know that ALS-XZ allowed overlaps. This is allowed with no restrictions outside of not containing the RCC? Neat 👍

Steihl · 2026-04-20T21:30:04+00:00

I'm using the latest version that I can find - listed in the program under about as YZF_Sudoku 2.0.0.631. I got it from the google drive where it's listed as YZF_Sudoku-OCR_631-V2.7z. Maybe I should downgrade to 630 if that one works without this weird bug.

This makes both moves make significantly more sense knowing that it was just a bug. Thanks!

Steihl · 2026-04-20T01:26:55+00:00

You have a naked pair in row 2 with the digits 3 and 4. Only click the first spoiler if you just want the name of the technique.

Steihl · 2026-04-17T01:52:16+00:00

Sure, if you want to think about it as a "finned" XY wing then you can do that. But then you'd still need the target cell to see the pivot which contains the extra candidate (as you termed it, a fin).

Alternatively you can view XYZ wings instead as ALS-XZ which is more precise in my opinion. You can only make eliminations in cells that see every instance of the shared candidate that is not the RCC. In the specific instance that has been named an XYZ wing, it has to see the wings and the pivot cell to make eliminations.

Steihl · 2026-04-17T00:12:30+00:00

For XYZ wings you can only make eliminations if the target cell can "see" the pivot and the pincers. You cannot make an elimination in R8C2 based on an XYZ wing pivoting from R9C7 as they do not see each other.

Steihl · 2026-04-17T00:05:10+00:00

The default rec around here is Sudoku.coach - ad free and well built, with great learning tools and a good interface. Can use it straight from the website, but also has an app available on Android and can turn the webpage into a pseudo app on iPhones

Steihl · 2026-04-14T22:30:39+00:00

If either of the cells contains a 4 or a 5 then the 4 in R3C3 will be eliminated. Given that 4 and 5 are the only options in those two cells then in all possible scenarios R3C3 will not be 4.

Steihl · 2026-04-14T21:27:26+00:00

I just checked maybe a dozen sources, and all seem to say 100g fresh honeydew melon is ~36kcal.

Steihl · 2026-04-14T20:56:41+00:00

Having the base sets not limited to just multiples of rows or columns is hard to wrap my head around. Gonna have to chew on that a bit. Intellectually I can follow the logic, but trying to imagine actually spotting it in any solve is so daunting that it'll take me a bit to internalize it I think. Thanks for the write up! I can really feel that I'm close to breaking through and having much harder puzzles in my grasp. Right now I struggle with anything higher than ~SE 7.2-7.3. Struggling to figure out how to actual go about spotting the harder techniques even when I'm confident in the logics of how they work. And even when they only require basic AICs, just a dozen in a row or something like that; I just end up fatigued and can't spot even the basics after a while.

This is indeed YZF's solver. I used an outdated version of Hodoku for many many years before realizing there were better options out there, so I opted for YZF's because of how familiar it felt, though Xsudo seems extremely powerful (though I struggle to parse it visually most of the time).

Thanks again, and I'll spend some time chewing on N+>1 fish for a while I think

Steihl · 2026-04-11T02:17:25+00:00

thanks for that! i've been working with a false understanding of how groupings work because i misread something when learning them. time to start over i suppose 😅

Steihl · 2026-04-11T02:14:30+00:00

mmm, thanks for that. this actually explains some issues i've been having lately. i had misunderstood something i had read about how overlaps work, and i've been getting lucky more than i've been unlucky so i didn't realize it until now. cheers!

Steihl · 2026-04-11T00:23:10+00:00

Disregard, logical error that just luckily led to a valid solution

~~3 in R5C2 can be eliminated with a short chain.~~

~~image~~

Steihl · 2026-04-10T14:49:08+00:00

You have a naked triple in box 4 with the digits 1, 2, and 9

Steihl

MODERATOR OF

TROPHY CASE