Simplify tropism. (#1807)

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index e6938e189f4312f3eaff82f68c2645f9c0701533..97218baa19f9627cb27ce59948c255e18cef0b81 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -421,7 +421,7 @@ namespace {
     // which are attacked twice in that flank but not defended by our pawns.
     kingFlank = KingFlank[file_of(ksq)];
     b1 = attackedBy[Them][ALL_PIECES] & kingFlank & Camp;
-    b2 = b1 & attackedBy2[Them] & ~attackedBy[Us][PAWN];
+    b2 = b1 & attackedBy2[Them];
 
     int tropism = popcount(b1) + popcount(b2);