From e48c7547c50d56b7aa7fd4a244533daca1ef6a57 Mon Sep 17 00:00:00 2001 From: ElbertoOne Date: Sat, 4 Jun 2016 07:10:43 +0200 Subject: [PATCH 1/1] LMR reduction parameter tweak More reduction for cut nodes, less for moves that escape a capture: STC (http://tests.stockfishchess.org/tests/view/57548c1e0ebc59029919b247): LLR: 2.96 (-2.94,2.94) [0.00,4.00] Total: 60165 W: 11519 L: 11149 D: 37497 LTC (http://tests.stockfishchess.org/tests/view/57555b570ebc59029919b260): LLR: 2.95 (-2.94,2.94) [0.00,4.00] Total: 10353 W: 1493 L: 1317 D: 7543 Bench: 8902859 --- src/search.cpp | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/src/search.cpp b/src/search.cpp index f0ee1b2b..d03a251f 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -1010,7 +1010,7 @@ moves_loop: // When in check search starts from here // Increase reduction for cut nodes if (!PvNode && cutNode) - r += ONE_PLY; + r += 2 * ONE_PLY; // Decrease reduction for moves that escape a capture. Filter out // castling moves, because they are coded as "king captures rook" and @@ -1019,7 +1019,7 @@ moves_loop: // When in check search starts from here else if ( type_of(move) == NORMAL && type_of(pos.piece_on(to_sq(move))) != PAWN && pos.see(make_move(to_sq(move), from_sq(move))) < VALUE_ZERO) - r -= ONE_PLY; + r -= 2 * ONE_PLY; // Decrease/increase reduction for moves with a good/bad history int rHist = (val - 10000) / 20000; -- 2.39.2