Remix.run Logo
Chess engines do weird stuff(girl.surgery)
69 points by admiringly 2 hours ago | 27 comments

Related: https://cosmo.tardis.ac/files/2026-02-12-az-rl-and-spsa.html

mpolson64 an hour ago | parent | next [-]

I'm no expert on chess engine development, but it's surprising to me that both lc0 and stockfish use SPSA for "tuning" the miscellaneous magic numbers which appear in the system rather than different black box optimization algorithms like Bayesian optimization or evolutionary algorithms. As far as I am aware both of these approaches are used more often for similar tasks in non-chess applications (ex. hyperparameter optimization in ML training) and have much more active research communities compared to SPSA.

Is there something special about these chess engines that makes SPSA more desirable for these use cases specifically? My intuition is that something like Bayesian optimization could yield stronger optimization results, and that the computational overhead of doing BO would be minimal compared to the time it takes to train and evaluate the models.

sscg13 8 minutes ago | parent [-]

Engines like Stockfish might have over 100 "search parameters" that need to be tuned, to my best knowledge SPSA is preferred because the computational cost typically does not depend on the number of parameters.

Or, if attempting to use SPSA to say, perform a final post-training tune to the last layers of a neural network, this could be thousands of parameters or more.

incognito124 an hour ago | parent | prev | next [-]

Please be careful when visiting the homepage

pavel_lishin an hour ago | parent | next [-]

This really reminds me of the web as I remember it from the mid-to-late 90's; I feel like I'm just a click away from the old deoxy.org, if anyone remembers that. (Don't go there now; the domain appears to have been long-ago hijacked.)

incognito124 an hour ago | parent [-]

or kittens on encyclopediabrittanica

NooneAtAll3 20 minutes ago | parent | prev | next [-]

as always, genius and insanity are only 1 step apart

hmmmmmmmmmmmmmm 4 minutes ago | parent [-]

Load of bullshit. Let's not romanticise mental illness.

You now have a generation of people who think it is cool to be mentally ill.

WesolyKubeczek an hour ago | parent | prev [-]

It gave me serious vibes of the old internet homepages of highly eccentric people that became a part of the internet folklore, whether in a good way or a bad way.

The video is probably the least bizarre thing there, if that's what you are warning about.

uncivilized an hour ago | parent [-]

What were you browsing where someone cutting off their own testicles is not as bizarre as other things? I didn't watch the video but atleast there was a warning.

Feds this guy right here ^^

pavel_lishin an hour ago | parent [-]

> What were you browsing where someone cutting off their own testicles is not as bizarre as other things?

One of my formative early internet experiences was loading up a video of a man being beheaded with a knife.

Luckily, I realized what was about to happen, and didn't subject myself to the whole thing.

t1234s 9 minutes ago | parent | prev | next [-]

The homepage for this site is defiantly NSFW.

RivieraKid an hour ago | parent | prev | next [-]

AFAIK chess is has been "solved" for a few years in the sense that Stockfish running on modern laptop with 1 minute per move is unbeatable from the starting position.

helloplanets an hour ago | parent | next [-]

This is not true. Stockfish is not unbeatable by another engine, or another copy of Stockfish.

Chess engines have been impossible for humans to beat for well over a decade.

But a position in chess being solved is a specific thing, which is still very far from having happened for the starting position. Chess has been solved up to 7 pieces. Solving basically amounts to some absolutely massive tables that have every variation accounted for, so that you know whether a given position will end in a draw, black win or white win. (https://syzygy-tables.info)

LeifCarrotson 17 minutes ago | parent | next [-]

The parent is using a different definition, so they put "solved" in quotes. What word would you suggest to describe the situation where the starting position with 32 pieces always ends in either a draw or win for white, regardless of the compute and creativity available to black?

I haven't verified OP's claim attributed to 'someone on the Stockfish discord', but if true, that's fascinating. There would be nothing left for the engine developers to do but improve efficiency and perhaps increase the win-to-draw ratio.

helloplanets 8 minutes ago | parent [-]

Yea that's true, it's a pretty overloaded word. From what I remember though, even the top players thought that there wasn't anywhere left to go with chess engines, before Alpha Zero basically ripped the roof off with a completely different play style back in 2017, beating Stockfish.

I guess my point is, that even if the current situation is basically a 'deadlock', it's been proven that it's not some sort of eternal knowledge of the game as of yet. There's still the possiblity that a new type of approach could blow the current top engines out of the water, with a completely different take on the game.

RivieraKid 44 minutes ago | parent | prev [-]

Do you have a source? I remember asking on the Stockfish Discord and being told that Stockfish on a modern laptop with 1 min per move will never lose against Stockfish with 1000 min per move from the starting position.

But I'm not sure whether that guy was guessing or confident about that claim.

LogicalRisk 2 minutes ago | parent | next [-]

Here's a game from a month ago where Stockfish loses to Lc0, played during the TCEC Cup. https://lichess.org/S9AwOvWn

Chess is a 2 player game of perfect, finite information, so by Zermelo's theorem either one side always wins with optimal play or it's a draw with optimal play. The argument from the Discord person simply says that Stockfish computationally can't come up with a way to beat itself. Whether this is true (and it really sounds like a question about depth in search) is separate from whether the game itself is solved, and it very much is not.

Solving chess would be a table that simply lists out the optimal strategy at every node in the game tree. Since this is computationally infeasible, we will certainly never solve chess absent some as yet unknown advance in computation.

helloplanets 20 minutes ago | parent | prev | next [-]

There's the TCEC [0] which is a big thing in some circles. Stockfish does lose every now and then against top engines. [1] Usually it's two different engines playing against one another, though. Like Leela Chess Zero [2] vs. Stockfish.

In that hypothetical of running 2 instances of Stockfish against one another on a modern laptop, with the key difference being minutes of compute time, it'd probably be very close to 100% of draws. Depending on how many games you run. So, if you run a million games, there's probably some outliers. If you run a hundred, maybe not.

When it comes to actually solved positions, the 7-piece tables take around 1TB of RAM to even run. These tablebases are used by Stockfish when you actually want to run it at peak strength. [3]

[0]: https://tcec-chess.com [1]: https://lichess.org/broadcast/tcec-s28-leagues--superfinal/m... [2]: https://lczero.org [3]: https://github.com/syzygy1/tb

NooneAtAll3 18 minutes ago | parent [-]

doesn't TCEC use opening book?

I remember hearing that starting position is so draw-ish that it's not practical anymore

LogicalRisk 2 minutes ago | parent [-]

TCEC does force different openings yes. Engines play both sides.

MengerSponge 33 minutes ago | parent | prev [-]

That just means that Stockfish doesn't get stronger with more than 1 minute per move on a modern computer. It doesn't say anything about other engines.

RivieraKid 19 minutes ago | parent [-]

Stockfish with 1000 minutes per move is an approximation of a perfect chess player. So if Stockfish with 1 minute per move will never lose against a perfect player, it is unbeatable by any chess engine.

bee_rider 20 minutes ago | parent | prev | next [-]

“Solved” is a term of art. Defining it in some other way is not really wrong (since it is a definition) but it seems… unnecessary.

altruios an hour ago | parent | prev [-]

Even by a stockfish running on a modern laptop with 2 minutes per move (provided they are going second)?!

RivieraKid 42 minutes ago | parent [-]

Yes, that's what "unbeatable from the starting position" means.

GaggiX 2 hours ago | parent | prev [-]

https://cosmo.tardis.ac/files/2026-02-12-az-rl-and-spsa.html

Response from the author of Viridithas, there is a link to this engine in her webpage.

dang an hour ago | parent [-]

Thanks! I've put that link in the toptext as well.