From d0804341c5ec422c19e34db20756d123d03464e0 Mon Sep 17 00:00:00 2001 From: Marco Costalba Date: Mon, 5 Jan 2009 15:14:16 +0100 Subject: [PATCH] Piece mobility: filter out squares protected by pawns Do not consider squares protected by enemy pawns in mobility evaluation. This reduces the mobility value by about 15% Signed-off-by: Marco Costalba --- src/evaluate.cpp | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/src/evaluate.cpp b/src/evaluate.cpp index 12329fcd..d261f448 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -575,8 +575,11 @@ namespace { ei.kingAdjacentZoneAttacksCount[us] += count_1s_max_15(bb); } + // Remove squares protected by enemy pawns + Bitboard bb = (b & ~ei.attackedBy[them][PAWN]); + // Mobility - int mob = count_1s_max_15(b & ~p.pieces_of_color(us)); + int mob = count_1s_max_15(bb & ~p.pieces_of_color(us)); ei.mgMobility += Sign[us] * mgBonus[mob]; ei.egMobility += Sign[us] * egBonus[mob]; -- 2.39.2