From bc3c215490edf24cef0ff87d74ab01eeb91ae1bc Mon Sep 17 00:00:00 2001 From: Vizvezdenec Date: Wed, 17 Jun 2020 05:36:30 +0300 Subject: [PATCH] More reduction for evading pawn moves. pawn moves are irreversable unlike other evading moves; pawn is the least valuable piece in the game. So it makes a lot of sence to assume that evading pawn moves are on average not as good as other evading moves thus can be reduced more. Passed STC https://tests.stockfishchess.org/tests/view/5ee9602e563bc7aa756002dc LLR: 2.95 (-2.94,2.94) {-0.50,1.50} Total: 94176 W: 17993 L: 17668 D: 58515 Ptnml(0-2): 1634, 10742, 21989, 11111, 1612 Passed LTC https://tests.stockfishchess.org/tests/view/5ee97342563bc7aa75600301 LLR: 2.94 (-2.94,2.94) {0.25,1.75} Total: 20432 W: 2572 L: 2354 D: 15506 Ptnml(0-2): 146, 1707, 6280, 1949, 134 closes https://github.com/official-stockfish/Stockfish/pull/2749 Bench: 5073064 --- src/search.cpp | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/search.cpp b/src/search.cpp index 67339ed7..d96ed7da 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -1186,7 +1186,7 @@ moves_loop: // When in check, search starts from here // hence break make_move(). (~2 Elo) else if ( type_of(move) == NORMAL && !pos.see_ge(reverse_move(move))) - r -= 2 + ttPv; + r -= 2 + ttPv - (type_of(movedPiece) == PAWN); ss->statScore = thisThread->mainHistory[us][from_to(move)] + (*contHist[0])[movedPiece][to_sq(move)] -- 2.39.2