Dev Builds » 20221105-0815

Use this dev build

NCM plays each Stockfish dev build 20,000 times against Stockfish 15. This yields an approximate Elo difference and establishes confidence in the strength of the dev builds.

Summary

Host Duration Avg Base NPS Games WLD Standard Elo Ptnml(0-2) Gamepair Elo

Test Detail

ID Host Base NPS Games WLD Standard Elo Ptnml(0-2) Gamepair Elo CLI PGN

Commit

Commit ID ad2aa8c06f438de8b8bb7b7c8726430e3f2a5685
Author Joost VandeVondele
Date 2022-11-05 08:15:53 UTC
Normalize evaluation Normalizes the internal value as reported by evaluate or search to the UCI centipawn result used in output. This value is derived from the win_rate_model() such that Stockfish outputs an advantage of "100 centipawns" for a position if the engine has a 50% probability to win from this position in selfplay at fishtest LTC time control. The reason to introduce this normalization is that our evaluation is, since NNUE, no longer related to the classical parameter PawnValueEg (=208). This leads to the current evaluation changing quite a bit from release to release, for example, the eval needed to have 50% win probability at fishtest LTC (in cp and internal Value): June 2020 : 113cp (237) June 2021 : 115cp (240) April 2022 : 134cp (279) July 2022 : 167cp (348) With this patch, a 100cp advantage will have a fixed interpretation, i.e. a 50% win chance. To keep this value steady, it will be needed to update the win_rate_model() from time to time, based on fishtest data. This analysis can be performed with a set of scripts currently available at https://github.com/vondele/WLD_model fixes https://github.com/official-stockfish/Stockfish/issues/4155 closes https://github.com/official-stockfish/Stockfish/pull/4216 No functional change
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