diff --git a/src/evaluate.cpp b/src/evaluate.cpp index 787004b4..1ff2dea7 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -172,6 +172,7 @@ namespace { const Score RookOpenFile = make_score(43, 21); const Score RookSemiopenFile = make_score(19, 10); const Score BishopPawns = make_score( 8, 12); + const Score KnightPawns = make_score( 8, 4); const Score MinorBehindPawn = make_score(16, 0); const Score UndefendedMinor = make_score(25, 10); const Score TrappedRook = make_score(90, 0); @@ -529,6 +530,10 @@ Value do_evaluate(const Position& pos, Value& margin) { if (Piece == BISHOP) score -= BishopPawns * ei.pi->pawns_on_same_color_squares(Us, s); + // Penalty for knight when there are few enemy pawns + if (Piece == KNIGHT) + score -= KnightPawns * std::max(5 - pos.count(Them), 0); + if (Piece == BISHOP || Piece == KNIGHT) { // Bishop and knight outposts squares