From 46ce245763705c89dba60dcfda549dc1f64eb48b Mon Sep 17 00:00:00 2001 From: VoyagerOne Date: Fri, 14 Jun 2019 13:59:17 -0400 Subject: [PATCH 1/1] Simplify SEE Pruning (#2191) Simplify SEE Pruning Note this should also be a speedup... If givesCheck is extended we know (except for DC) that it will have a positive SEE. So this new logic will be triggered before doing another expensive SEE function. STC: LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 24429 W: 5484 L: 5368 D: 13577 http://tests.stockfishchess.org/tests/view/5cffbccd0ebc5925cf09a154 LTC: LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 28428 W: 4873 L: 4765 D: 18790 http://tests.stockfishchess.org/tests/view/5d0015f60ebc5925cf09acb1 Bench: 3897263 --- src/search.cpp | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/search.cpp b/src/search.cpp index 50bce13c..d9543899 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -980,7 +980,7 @@ moves_loop: // When in check, search starts from here if (!pos.see_ge(move, Value(-29 * lmrDepth * lmrDepth))) continue; } - else if ((!givesCheck || !(pos.blockers_for_king(~us) & from_sq(move))) + else if ((!givesCheck || !extension) && !pos.see_ge(move, -PawnValueEg * (depth / ONE_PLY))) // (~20 Elo) continue; } -- 2.39.2