Add bonuses for Minors attacking enemy pieces(except pawns) even when they are protec...
authorAjith <achajo@yahoo.co.in>
Mon, 30 Jun 2014 14:55:10 +0000 (10:55 -0400)
committerGary Linscott <glinscott@gmail.com>
Mon, 30 Jun 2014 14:55:10 +0000 (10:55 -0400)
Patch passed STC
LLR: 2.95 (-2.94,2.94) [-1.50,4.50]
Total: 8206 W: 1426 L: 1304 D: 5476

and LTC
LLR: 2.97 (-2.94,2.94) [0.00,6.00]
Total: 19534 W: 2821 L: 2640 D: 14073

Bench: 9942172

src/evaluate.cpp

index 7fb3a8c..f17c575 100644 (file)
@@ -496,9 +496,17 @@ namespace {
 
     const Color Them = (Us == WHITE ? BLACK : WHITE);
 
-    Bitboard b, weakEnemies;
+    Bitboard b, weakEnemies, protectedEnemies;
     Score score = SCORE_ZERO;
 
+    // Protected enemies
+    protectedEnemies = (pos.pieces(Them) ^ pos.pieces(Them,PAWN))
+                      & ei.attackedBy[Them][PAWN]
+                      & (ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP]);
+
+    if(protectedEnemies)
+        score += Threat[0][type_of(pos.piece_on(lsb(protectedEnemies)))];
+
     // Enemies not defended by a pawn and under our attack
     weakEnemies =  pos.pieces(Them)
                  & ~ei.attackedBy[Them][PAWN]