Search found 2109 matches

by Michel
Tue Jan 12, 2021 8:32 am
Forum: Computer Chess Club: General Topics
Topic: Do you test engines with or without using a book?
Replies: 27
Views: 2738

Re: Do you test engines with or without using a book?

The book currently in use a Fishtest has a RMS bias of 30 elo which in score units corresponds to 0.043 (1% score=7Elo). Well, 30 Elo is already larger than the white advantage. I would not call that anywhere near balanced. Of course at these high draw ratios it might be better to use a very unbala...
by Michel
Mon Jan 11, 2021 3:57 pm
Forum: Computer Chess Club: General Topics
Topic: Do you test engines with or without using a book?
Replies: 27
Views: 2738

Re: Do you test engines with or without using a book?

Replaying games with reversed colors reduces the variance of the test outcome (one should use the pentanomial model to correctly estimate this variance). So you need fewer games to reach a decision. This effect is quite substantial. Fishtest (which is the gold standard in engine testing) uses a ver...
by Michel
Wed Jan 06, 2021 5:56 am
Forum: Computer Chess Club: General Topics
Topic: Do you test engines with or without using a book?
Replies: 27
Views: 2738

Re: Do you test engines with or without using a book?

Replaying games with reversed colors reduces the variance of the test outcome (one should use the pentanomial model to correctly estimate this variance). So you need fewer games to reach a decision. This effect is quite substantial. Fishtest (which is the gold standard in engine testing) uses a very...
by Michel
Sun Jan 03, 2021 3:37 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: YBW engines past and present?
Replies: 15
Views: 1336

Re: YBW engines past and present?

It's insane that seemingly small tweaks to what was considered the worst-scaling algorithm (shared hash table) somehow produces the best one. It was never "worst scaling". In fact the old Toga used an extremely simple implementation of shared hash and its scaling was comparable to YBW engines. One ...
by Michel
Thu Dec 31, 2020 10:54 am
Forum: Computer Chess Club: General Topics
Topic: Dispelling the Myth of NNUE with LazySMP: An Analysis
Replies: 39
Views: 1877

Re: Dispelling the Myth of NNUE with LazySMP: An Analysis

OK! Got it. I will look at that maybe in the new year. My project for today is creating a program to disassemble polyglot books. Somebody said that program does not exist. If not, it will exist shortly. Look at the polyglot option dump-book. This may be what you want. Below some sample output. Dump...
by Michel
Tue Dec 22, 2020 8:04 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Position Causes Stockfish and Komodo To Crash
Replies: 135
Views: 9782

Re: Position causes StockFish and Komodo to crash.

Thanks. It seems I was wrong. In your position SF does find the ep move. Then I wonder why it does not consider the ep move in the parentless position... Why generating an illegal move? Why do you consider the ep move illegal? Because this kind of move can NEVER occur in a legal game of chess. So I...
by Michel
Tue Dec 22, 2020 7:57 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Position Causes Stockfish and Komodo To Crash
Replies: 135
Views: 9782

Re: Position causes StockFish and Komodo to crash.

Hello again: Thanks. It seems I was wrong. In your position SF does find the ep move. Then I wonder why it does not consider the ep move in the parentless position... The key could be in movegen.cpp . There is a three-line comment at current lines 159-161: // An en passant capture can be an evasion...
by Michel
Tue Dec 22, 2020 7:48 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Position Causes Stockfish and Komodo To Crash
Replies: 135
Views: 9782

Re: Position causes StockFish and Komodo to crash.

Hello Michel: An interesting issue here https://github.com/official-stockfish/Stockfish/issues/3270 SF move generation assumes (correctly it seems) that in a game an escape move can never be an ep move. But of course one can create positions (without parent) in which there is an escape move which i...
by Michel
Tue Dec 22, 2020 6:37 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Position Causes Stockfish and Komodo To Crash
Replies: 135
Views: 9782

Re: Position causes StockFish and Komodo to crash.

Hello Michel: An interesting issue here https://github.com/official-stockfish/Stockfish/issues/3270 SF move generation assumes (correctly it seems) that in a game an escape move can never be an ep move. But of course one can create positions (without parent) in which there is an escape move which i...
by Michel
Tue Dec 22, 2020 9:36 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Position Causes Stockfish and Komodo To Crash
Replies: 135
Views: 9782

Re: Position Causes Stockfish and Komodo To Crash

An interesting issue here https://github.com/official-stockfish/Stockfish/issues/3270 SF move generation assumes (correctly it seems) that in a game an escape move can never be an ep move. But of course one can create positions (without parent) in which there is an escape move which is indeed an ep ...