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NCM plays each Stockfish dev build 20,000 times against Stockfish 14. This yields an approximate Elo difference and establishes confidence in the strength of the dev builds.


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Commit ID 434b2c72a44ba255c14957f519e3993ea3d5d6bc
Author 31m059
Date 2019-06-09 12:19:07 UTC
Simplify k-value for passers. Bench: 3854907 (#2182) Stockfish evaluates passed pawns in part based on a variable k, which shapes the passed pawn bonus based on the number of squares between the current square and promotion square that are attacked by enemy pieces, and the number defended by friendly ones. Prior to this commit, we gave a large bonus when all squares between the pawn and the promotion square were defended, and if they were not, a somewhat smaller bonus if at least the pawn's next square was. However, this distinction does not appear to provide any Elo at STC or LTC. Where do we go from here? Many promising Elo-gaining patches were attempted in the past few months to refine passed pawn calculation, by altering the definitions of unsafe and defended squares. Stockfish uses these definitions to choose the value of k, so those tests interact with this PR. Therefore, it may be worthwhile to retest previously promising but not-quite-passing tests in the vicinity of this patch. STC: LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 42344 W: 9455 L: 9374 D: 23515 LTC: LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 69548 W: 11855 L: 11813 D: 45880 Bench: 3854907
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