Rank threats on pinned pawns

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 7309f9f31a6c5e7c7de25bdaac4e75394f9f9f57..ac9cf90bdcb314aad1198af283f0ab8d9662eb6c 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -540,6 +540,9 @@ namespace {
             score += ThreatByMinor[type_of(pos.piece_on(s))];
             if (type_of(pos.piece_on(s)) != PAWN)
                 score += ThreatByRank * (int)relative_rank(Them, s);
             score += ThreatByMinor[type_of(pos.piece_on(s))];
             if (type_of(pos.piece_on(s)) != PAWN)
                 score += ThreatByRank * (int)relative_rank(Them, s);

+
+            else if (pos.blockers_for_king(Them) & s)
+                score += ThreatByRank * (int)relative_rank(Them, s) / 2;

         }
 
         b = weak & attackedBy[Us][ROOK];
         }
 
         b = weak & attackedBy[Us][ROOK];


@@ -549,6 +552,9 @@ namespace {
             score += ThreatByRook[type_of(pos.piece_on(s))];
             if (type_of(pos.piece_on(s)) != PAWN)
                 score += ThreatByRank * (int)relative_rank(Them, s);
             score += ThreatByRook[type_of(pos.piece_on(s))];
             if (type_of(pos.piece_on(s)) != PAWN)
                 score += ThreatByRank * (int)relative_rank(Them, s);

+
+            else if (pos.blockers_for_king(Them) & s)
+                score += ThreatByRank * (int)relative_rank(Them, s) / 2;

         }
 
         if (weak & attackedBy[Us][KING])
         }
 
         if (weak & attackedBy[Us][KING])