From d320de761951687fa55716da1bd786df4c2cb14b Mon Sep 17 00:00:00 2001 From: xoto10 Date: Sun, 10 Mar 2019 21:57:48 +0000 Subject: [PATCH] Remove !extension check #2045 While looking at pruning using see_ge() (which is very valuable) it became apparent that the !extension test is not adding any value - simplify it away. STC: LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 56843 W: 12621 L: 12569 D: 31653 http://tests.stockfishchess.org/tests/view/5c8588cb0ebc5925cffe77f4 LTC: LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 78622 W: 13223 L: 13195 D: 52204 http://tests.stockfishchess.org/tests/view/5c8611cc0ebc5925cffe7f86 Further work could be to optimize the remaining see_ge() test. The idea of less pruning at higher depths is valuable, but perhaps the test (-PawnValueEg * depth) can be improved. Bench: 3188688 --- src/search.cpp | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/src/search.cpp b/src/search.cpp index cf934fc9..7043e49d 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -970,8 +970,7 @@ moves_loop: // When in check, search starts from here if (!pos.see_ge(move, Value(-29 * lmrDepth * lmrDepth))) continue; } - else if ( !extension // (~20 Elo) - && !pos.see_ge(move, -PawnValueEg * (depth / ONE_PLY))) + else if (!pos.see_ge(move, -PawnValueEg * (depth / ONE_PLY))) // (~20 Elo) continue; } -- 2.39.2