Extend King Threats to all pieces (other than pawns).

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index a0e22516002acbd0b2aebf8eb66e50918f6dec25..ae52d203ffc0b565b317aa1d945de1bd468b71b3 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -151,8 +151,8 @@ namespace {
   };
 
   // Assorted bonuses and penalties used by evaluation
-  const Score KingOnPawnOne    = S(0 , 64);
-  const Score KingOnPawnMany   = S(0 ,128);
+  const Score KingOnOne        = S(2 , 58);
+  const Score KingOnMany       = S(6 ,125);
   const Score RookOnPawn       = S(10, 28);
   const Score RookOpenFile     = S(43, 21);
   const Score RookSemiOpenFile = S(19, 10);
@@ -221,7 +221,7 @@ namespace {
     ei.attackedBy[Us][ALL_PIECES] = ei.attackedBy[Us][PAWN] = ei.pi->pawn_attacks(Us);
 
     // Init king safety tables only if we are going to use them
-    if (pos.count<QUEEN>(Us) && pos.non_pawn_material(Us) > QueenValueMg + PawnValueMg)
+    if (pos.non_pawn_material(Us) > QueenValueMg + PawnValueMg)
     {
         ei.kingRing[Them] = b | shift_bb<Down>(b);
         b &= ei.attackedBy[Us][PAWN];
@@ -414,7 +414,8 @@ namespace {
         attackUnits =  std::min(20, (ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2)
                      + 3 * (ei.kingAdjacentZoneAttacksCount[Them] + popcount<Max15>(undefended))
                      + 2 * (ei.pinnedPieces[Us] != 0)
-                     - mg_value(score) / 32;
+                     - mg_value(score) / 32
+                     - !pos.count<QUEEN>(Them) * 15;
 
         // Analyse the enemy's safe queen contact checks. Firstly, find the
         // undefended squares around the king that are attacked by the enemy's
@@ -506,7 +507,7 @@ namespace {
                       & ei.attackedBy[Them][PAWN]
                       & (ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP]);
 
-    if(protectedEnemies)
+    if (protectedEnemies)
         score += Threat[Minor][type_of(pos.piece_on(lsb(protectedEnemies)))];
 
     // Enemies not defended by a pawn and under our attack
@@ -529,9 +530,9 @@ namespace {
         if (b)
             score += more_than_one(b) ? Hanging * popcount<Max15>(b) : Hanging;
 
-        b = weakEnemies & pos.pieces(Them, PAWN) & ei.attackedBy[Us][KING];
+        b = weakEnemies & ei.attackedBy[Us][KING];
         if (b)
-            score += more_than_one(b) ? KingOnPawnMany : KingOnPawnOne;
+            score += more_than_one(b) ? KingOnMany : KingOnOne;
     }
 
     if (Trace)
@@ -607,7 +608,7 @@ namespace {
 
                 mbonus += k * rr, ebonus += k * rr;
             }
-            else if(pos.pieces(Us) & blockSq)
+            else if (pos.pieces(Us) & blockSq)
                 mbonus += rr * 3 + r * 2 + 3, ebonus += rr + r * 2;
         } // rr != 0