Give bonus for bishops that are alligned with enemy kingring.

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index ad79db5c4dc30164e6fdf183e534725c1d368bee..dc7134a8818bdd6874ec555eeef935502a13eeaa 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -128,6 +128,7 @@ namespace {
 
   // Assorted bonuses and penalties
   constexpr Score BishopPawns         = S(  3,  7);
 
   // Assorted bonuses and penalties
   constexpr Score BishopPawns         = S(  3,  7);

+  constexpr Score BishopOnKingRing    = S( 24,  0);

   constexpr Score BishopXRayPawns     = S(  4,  5);
   constexpr Score CorneredBishop      = S( 50, 50);
   constexpr Score FlankAttacks        = S(  8,  0);
   constexpr Score BishopXRayPawns     = S(  4,  5);
   constexpr Score CorneredBishop      = S( 50, 50);
   constexpr Score FlankAttacks        = S(  8,  0);


@@ -288,9 +289,13 @@ namespace {
             kingAttackersWeight[Us] += KingAttackWeights[Pt];
             kingAttacksCount[Us] += popcount(b & attackedBy[Them][KING]);
         }
             kingAttackersWeight[Us] += KingAttackWeights[Pt];
             kingAttacksCount[Us] += popcount(b & attackedBy[Them][KING]);
         }

+

         else if (Pt == ROOK && (file_bb(s) & kingRing[Them]))
             score += RookOnKingRing;
 
         else if (Pt == ROOK && (file_bb(s) & kingRing[Them]))
             score += RookOnKingRing;
 

+        else if (Pt == BISHOP && (attacks_bb<BISHOP>(s, pos.pieces(PAWN)) & kingRing[Them]))
+            score += BishopOnKingRing;
+

         int mob = popcount(b & mobilityArea[Us]);
 
         mobility[Us] += MobilityBonus[Pt - 2][mob];
         int mob = popcount(b & mobilityArea[Us]);
 
         mobility[Us] += MobilityBonus[Pt - 2][mob];