From 18279b24fc76bb6eaf6ac01f3032b1b90da5dabb Mon Sep 17 00:00:00 2001 From: protonspring Date: Tue, 20 Aug 2019 19:52:18 -0600 Subject: [PATCH] Tuned Futility Equation @Vizvezdenec array suggested that alternate values may be better than current master (see pull request #2270 ). I tuned some linear equations to more closely represent his values and it passed. These futility values seem quite sensitive, so perhaps additional Elo improvements can be found here. STC LLR: 2.95 (-2.94,2.94) [0.50,4.50] Total: 12257 W: 2820 L: 2595 D: 6842 http://tests.stockfishchess.org/tests/view/5d5b2f360ebc5925cf1111ac LTC LLR: 2.96 (-2.94,2.94) [0.00,3.50] Total: 20273 W: 3497 L: 3264 D: 13512 http://tests.stockfishchess.org/tests/view/5d5c0d250ebc5925cf111ac3 Closes https://github.com/official-stockfish/Stockfish/pull/2272 ------------------------------------------ How to continue from there ? a) we can try a simpler version for the futility margin, this would be a simplification : margin = 188 * (depth - improving) b) on the other direction, we can try a complexification by trying again to gain Elo with an complete array of futility values. ------------------------------------------ Bench: 4330402 --- src/search.cpp | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/search.cpp b/src/search.cpp index b154c6d9..69488ad5 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -64,7 +64,7 @@ namespace { // Razor and futility margins constexpr int RazorMargin = 661; Value futility_margin(Depth d, bool improving) { - return Value((168 - 51 * improving) * d / ONE_PLY); + return Value(198 * (d / ONE_PLY) - 178 * improving); } // Reductions lookup table, initialized at startup -- 2.39.2