X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fevaluate.cpp;h=3099924c0f2be48c2da9fde43c2303c562fcdb2b;hp=4f99eb870e5fc712ea7121fb6d042407a711c793;hb=2eec710318255df054a77abb7cd48d680453fd26;hpb=4758fd31b17129530dfeb81119b423c5bdde704a

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 4f99eb87..3099924c 100644
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -152,6 +152,8 @@ namespace {
 
   // Hanging contains a bonus for each enemy hanging piece
   const Score Hanging = S(23, 20);
+  const Score KingPawnThreatOne  = S(0, 64);
+  const Score KingPawnThreatMany = S(0, 128);
 
   #undef S
 
@@ -498,6 +500,7 @@ namespace {
 
     Bitboard b, weakEnemies, protectedEnemies;
     Score score = SCORE_ZERO;
+    enum { Minor, Major };
 
     // Protected enemies
     protectedEnemies = (pos.pieces(Them) ^ pos.pieces(Them,PAWN))
@@ -505,7 +508,7 @@ namespace {
                       & (ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP]);
 
     if(protectedEnemies)
-        score += Threat[0][type_of(pos.piece_on(lsb(protectedEnemies)))];
+        score += Threat[Minor][type_of(pos.piece_on(lsb(protectedEnemies)))];
 
     // Enemies not defended by a pawn and under our attack
     weakEnemies =  pos.pieces(Them)
@@ -517,16 +520,20 @@ namespace {
     {
         b = weakEnemies & (ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP]);
         if (b)
-            score += Threat[0][type_of(pos.piece_on(lsb(b)))];
+            score += Threat[Minor][type_of(pos.piece_on(lsb(b)))];
 
         b = weakEnemies & (ei.attackedBy[Us][ROOK] | ei.attackedBy[Us][QUEEN]);
         if (b)
-            score += Threat[1][type_of(pos.piece_on(lsb(b)))];
+            score += Threat[Major][type_of(pos.piece_on(lsb(b)))];
 
         b = weakEnemies & ~ei.attackedBy[Them][ALL_PIECES];
         if (b)
             score += more_than_one(b) ? Hanging * popcount<Max15>(b) : Hanging;
-    }
+
+        b = weakEnemies & pos.pieces(Them, PAWN) & ei.attackedBy[Us][KING];
+        if (b)
+            score += more_than_one(b) ? KingPawnThreatMany : KingPawnThreatOne;
+	}
 
     if (Trace)
         Tracing::terms[Us][Tracing::THREAT] = score;