// 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);