X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fevaluate.cpp;h=1ff2dea7744c520daff7073c2bc315f0778648af;hp=787004b4e7ac59b65f20b8764dae93358aaa5274;hb=f011a5af116ed3331c7f6fb36a57d9e6de8a3ae6;hpb=67b0da83da343cb6046f2a2f088f7aa1a6276637

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<PAWN>(Them), 0);
+
         if (Piece == BISHOP || Piece == KNIGHT)
         {
             // Bishop and knight outposts squares