Do not consider discovered checks in king safety

Does not help and it slows downs a bit because it
is not cheap to get the possible discovered checks
out of a position.

After 997 games at 1+0
Mod vs orig +153 =692 -152  +0 ELO

Signed-off-by: Marco Costalba <mcostalba@gmail.com>

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index fe28da3..e44bcdc 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -761,12 +761,6 @@ namespace {
         if (b)
             attackUnits += KnightCheckBonus * count_1s_max_15<HasPopCnt>(b);
 
-        // Analyse enemy's discovered checks (only for non-pawns right now,
-        // consider adding pawns later).
-        b = pos.discovered_check_candidates(Them) & ~pos.pieces(PAWN);
-        if (b)
-            attackUnits += DiscoveredCheckBonus * count_1s_max_15<HasPopCnt>(b) * (sente ? 2 : 1);
-
         // To index KingDangerTable[] attackUnits must be in [0, 99] range
         attackUnits = Min(99, Max(0, attackUnits));