MadChess 3.0 Beta

Discussion of anything and everything relating to chess playing software and machines.

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emadsen
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Re: MadChess 3.0 Beta

Post by emadsen » Tue Nov 27, 2018 1:20 pm

Thanks Steve. I have not tried PBIL algorithms, though I did follow Thomas' posts with great interest a few years ago. PSO minimizing the evaluation error over a large collection of GM games seems like rough estimating compared to PBIL, which "genetically" modifies engines then plays games to enforce survival of the fittest. It definitely requires a lot of computing resources, but because it judges fitness with actual engine-versus-engine games it's probably more likely to find real improvements.

I'd like to experiment with PBIL at some point. Thanks for suggesting the video lecture.
My C# chess engine: http://www.madchess.net

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emadsen
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Re: MadChess 3.0 Beta

Post by emadsen » Tue Dec 04, 2018 5:34 am

I improved the history heuristics used by MadChess 3.0 Beta's Late Move Reductions (LMR), gaining 28 ELO points. It's now rated 2171 +/- 20 ELO at bullet chess. The evaluation function still is limited to to material, piece location, draw detection, and checkmate.
My C# chess engine: http://www.madchess.net

PK
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Re: MadChess 3.0 Beta

Post by PK » Wed Dec 05, 2018 8:35 am

Regarding history, one possible enhancement is to update history for a hash move if hash score exceeds beta. At least it helped for me a tiny bit.

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emadsen
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Re: MadChess 3.0 Beta

Post by emadsen » Wed Dec 05, 2018 3:02 pm

Thanks for the tip, Pawel. I can’t remember if I update history for quiet best moves that were retrieved from the hashtable. I’ll check when I get home tonight.
My C# chess engine: http://www.madchess.net

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