diff --git a/src/evaluate.cpp b/src/evaluate.cpp index 5c1f7496..37cdce99 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -701,9 +701,18 @@ namespace { ei.attackedBy[WHITE][ALL_PIECES] |= ei.attackedBy[WHITE][KING]; ei.attackedBy[BLACK][ALL_PIECES] |= ei.attackedBy[BLACK][KING]; - // Do not include in mobility squares protected by enemy pawns or occupied by our pawns or king - Bitboard mobilityArea[] = { ~(ei.attackedBy[BLACK][PAWN] | pos.pieces(WHITE, PAWN, KING)), - ~(ei.attackedBy[WHITE][PAWN] | pos.pieces(BLACK, PAWN, KING)) }; + // Pawns blocked or on ranks 2 and 3. Will be excluded from the mobility area + Bitboard blockedPawns[] = { + pos.pieces(WHITE, PAWN) & (shift_bb(pos.pieces()) | Rank2BB | Rank3BB), + pos.pieces(BLACK, PAWN) & (shift_bb(pos.pieces()) | Rank7BB | Rank6BB) + }; + + // Do not include in mobility squares protected by enemy pawns, or occupied + // by our blocked pawns or king. + Bitboard mobilityArea[] = { + ~(ei.attackedBy[BLACK][PAWN] | blockedPawns[WHITE] | pos.king_square(WHITE)), + ~(ei.attackedBy[WHITE][PAWN] | blockedPawns[BLACK] | pos.king_square(BLACK)) + }; // Evaluate pieces and mobility score += evaluate_pieces(pos, ei, mobility, mobilityArea);