From 85924db496af2fb8d70b6c89b17fc8541339ca19 Mon Sep 17 00:00:00 2001 From: VoyagerOne Date: Fri, 29 Jul 2016 23:28:03 -0400 Subject: [PATCH] Futility tweak Use a different margin for pruning child nodes. STC: LLR: 2.95 (-2.94,2.94) [0.00,5.00] Total: 16692 W: 3251 L: 3051 D: 10390 http://tests.stockfishchess.org/tests/view/579b95d10ebc591c761f5c03 LTC: LLR: 2.97 (-2.94,2.94) [0.00,5.00] Total: 24140 W: 3501 L: 3297 D: 17342 http://tests.stockfishchess.org/tests/view/579bb15d0ebc591c761f5c0b Bench: 7927017 --- src/search.cpp | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/src/search.cpp b/src/search.cpp index a81c8527..64e9028b 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -65,7 +65,7 @@ namespace { // Razoring and futility margin based on depth const int razor_margin[4] = { 483, 570, 603, 554 }; - Value futility_margin(Depth d) { return Value(200 * d); } + Value futility_margin(Depth d) { return Value(150 * d); } // Futility and reductions lookup tables, initialized at startup int FutilityMoveCounts[2][16]; // [improving][depth] @@ -926,7 +926,7 @@ moves_loop: // When in check search starts from here // Futility pruning: parent node if ( predictedDepth < 7 * ONE_PLY - && ss->staticEval + futility_margin(predictedDepth) + 256 <= alpha) + && ss->staticEval + 256 + 200 * predictedDepth / ONE_PLY <= alpha) continue; // Prune moves with negative SEE at low depths and below a decreasing -- 2.39.2