Search found 3992 matches

by jdart
Mon Apr 12, 2021 6:05 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Subroutines, shared variables, etc.
Replies: 8
Views: 273

Re: Subroutines, shared variables, etc.

Generally speaking, it is harder to understand and debug code that might affect global variables in addition to whatever arguments are passed to the function (aka "side effects"). It shouldn't really affect speed though.
by jdart
Tue Mar 30, 2021 8:02 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: King safety evaluation
Replies: 12
Views: 1467

Re: King safety evaluation

My code for this is complex, but the core of it sums attack "weights" for each piece attacking squares near the king. The weights depend on piece type and take into account "stacked" attackers like a Rook behind a Queen. The sum is then put through a sigmoid function. There is more to it than that -...
by jdart
Tue Mar 30, 2021 2:55 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: nnue-trainer
Replies: 10
Views: 1640

Re: nnue-trainer

I am aware of the random move options. Actually as I have posted before, the way gensfen does this seems to me unsound, because it will score the whole game with the ultimate result, even though a random move inserted in the middle can change the eval significantly, and so really then the previous p...
by jdart
Sun Mar 28, 2021 5:22 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: nnue-trainer
Replies: 10
Views: 1640

Re: nnue-trainer

Thanks for the responses. It just does not seem intuitive to me that the objective would depend on input size. That's not what I see with Texel tuning, for example. But maybe it is overfitted and/or the input should be more diverse. The gensfen program by default outputs all game positions past the ...
by jdart
Sun Mar 28, 2021 5:05 pm
Forum: Computer Chess Club: General Topics
Topic: EU Club Cup game
Replies: 1
Views: 562

EU Club Cup game

The EU Club Cup qualifers are happening, and the first round has some super-GMs paired against weaker players. This is what happens when you have to play Shirov. He offered a Queen sac on move 11, which was declined, but taking it loses, too. [Event "European Online Club-ch-A 2021"] [Site "Online"] ...
by jdart
Sat Mar 27, 2021 6:53 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: nnue-trainer
Replies: 10
Views: 1640

nnue-trainer

I am doing some experiments with https://github.com/bmdanielsson/nnue-trainer and have a couple of questions: 1. What's a typical number of positions for training and validation? 2. I am seeing that the objective values seem to go down with increasing training set size. For example, 5 million positi...
by jdart
Sat Mar 27, 2021 6:20 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Computers, Chess and Long-Range Planning, by Michail M. Botvinnik
Replies: 7
Views: 1215

Re: Computers, Chess and Long-Range Planning, by Michail M. Botvinnik

That book caused something of a stir when it first came out. It was basically advocating a kind of "Shannon Type B" strategy IIRC (https://www.chessprogramming.org/Type_B_Strategy). Botvinnik was involved in the development of a chess program called Pioneer that incorporated his ideas, but it was ne...
by jdart
Wed Mar 17, 2021 1:01 am
Forum: Computer Chess Club: General Topics
Topic: Positions Chess Engines Don't Understand
Replies: 6
Views: 717

Re: Positions Chess Engines Don't Understand

These are a few I have collected the past few months (besides the one I just posted with bm Bf7). I think Stockfish solves most if not all of these. But other engines may have trouble. r2qrbk1/5b1p/p1p2pp1/1pp5/P2nPNPP/2BPN3/1PP2R2/R5QK w - - bm axb5; c0 "SugarAI-Arasan, FICS 2021"; c1 "Arasan expec...
by jdart
Tue Mar 16, 2021 11:39 pm
Forum: Computer Chess Club: General Topics
Topic: another interesting position: evade the right way
Replies: 3
Views: 549

another interesting position: evade the right way

from an online game:



Bf7 wins, other moves only draw. Stockfish is fast on this. Other engines I have tried either don't select Bf7 or don't see it wins, at least with moderate depths.
by jdart
Mon Mar 15, 2021 6:49 pm
Forum: Computer Chess Club: General Topics
Topic: Give it to us - we want Stockfish
Replies: 20
Views: 3669

Re: Give it to us - we want Stockfish

Several commercial projects use Arasan as a chess engine. It is stronger than Crafty (didn't used to be, but is now). It is MIT licensed. I am pretty sure I don't even know how many software packages might use or include it, because they don't need to notify me.