Use stronglyProtected

31m059 · snicolet · commit 7240a90bf9be · 2018-12-16T10:04:49.000+01:00
~stronglyProtected is quite similar to ~attackedBy[Them][PAWN] & ~attackedBy2[Them], the only difference appears to be that the former includes squares attacked twice by both sides. The resulting logic is simpler, and the change appears to be at least Elo-neutral at both STC and LTC. STC: LLR: 2.95 (-2.94,2.94) [-3.00,1.00] Total: 35924 W: 7978 L: 7885 D: 20061 http://tests.stockfishchess.org/tests/view/5c14a5c00ebc5902ba11ed72 LTC: LLR: 2.96 (-2.94,2.94) [-3.00,1.00] Total: 37078 W: 6125 L: 6030 D: 24923 http://tests.stockfishchess.org/tests/view/5c14ae880ebc5902ba11eed8 Bench: 3646542
diff --git a/src/evaluate.cpp b/src/evaluate.cpp
@@ -560,8 +560,7 @@ namespace {
 
     // Bonus for restricting their piece moves
     restricted =   attackedBy[Them][ALL_PIECES]
-                & ~attackedBy[Them][PAWN]
-                & ~attackedBy2[Them]
+                & ~stronglyProtected
                 &  attackedBy[Us][ALL_PIECES];
     score += RestrictedPiece * popcount(restricted);
 
