diff --git a/src/evaluate.cpp b/src/evaluate.cpp index 67e05921..e663f21f 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -128,6 +128,7 @@ namespace { // Assorted bonuses and penalties constexpr Score BishopPawns = S( 3, 7); + constexpr Score BishopXRayPawns = S( 4, 5); constexpr Score CorneredBishop = S( 50, 50); constexpr Score FlankAttacks = S( 8, 0); constexpr Score Hanging = S( 69, 36); @@ -318,6 +319,9 @@ namespace { score -= BishopPawns * pos.pawns_on_same_color_squares(Us, s) * (!(attackedBy[Us][PAWN] & s) + popcount(blocked & CenterFiles)); + // Penalty for all enemy pawns x-rayed + score -= BishopXRayPawns * popcount(PseudoAttacks[BISHOP][s] & pos.pieces(Them, PAWN)); + // Bonus for bishop on a long diagonal which can "see" both center squares if (more_than_one(attacks_bb(s, pos.pieces(PAWN)) & Center)) score += LongDiagonalBishop;