Do not consider discovered checks in king safety

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 32bd35f6be805fe9514a9e35a587606881bc6422..e44bcdcc64aa942f0bb6206f87dad3543f809631 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -134,10 +134,10 @@ namespace {
   // piece type attacks which one.
   const Score ThreatBonus[8][8] = {
     {}, {},
-    { S(0, 0), S(18,37), S( 0, 0), S(37,47), S(55,97), S(55,97) }, // KNIGHT
-    { S(0, 0), S(18,37), S(37,47), S( 0, 0), S(55,97), S(55,97) }, // BISHOP
-    { S(0, 0), S( 9,27), S(27,47), S(27,47), S( 0, 0), S(37,47) }, // ROOK
-    { S(0, 0), S(27,37), S(27,37), S(27,37), S(27,37), S( 0, 0) }  // QUEEN
+    { S(0, 0), S( 7, 39), S( 0,  0), S(24, 49), S(41,100), S(41,100) }, // KNIGHT
+    { S(0, 0), S( 7, 39), S(24, 49), S( 0,  0), S(41,100), S(41,100) }, // BISHOP
+    { S(0, 0), S(-1, 29), S(15, 49), S(15, 49), S( 0,  0), S(24, 49) }, // ROOK
+    { S(0, 0), S(15, 39), S(15, 39), S(15, 39), S(15, 39), S( 0,  0) }  // QUEEN
   };
 
   // ThreatedByPawnPenalty[] contains a penalty according to which piece
@@ -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));
 
@@ -799,7 +793,7 @@ namespace {
         assert(pos.pawn_is_passed(Us, s));
 
         int r = int(relative_rank(Us, s) - RANK_2);
-        int tr = Max(0, r * (r - 1));
+        int tr = r * (r - 1);
 
         // Base bonus based on rank
         Value mbonus = Value(20 * tr);