Further streamline connected pawn evaluation

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 7892f3155c57e64fc2feff79d56569511c6eb92c..69df7629b881f1ce9e197d4b3b1695a7437379a6 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);
@@ -530,9 +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)
@@ -626,13 +626,13 @@ namespace {
   }
 
 
-  // evaluate_unstoppable_pawns() scores the most advanced among the passed and
-  // candidate pawns. In case both players have no pieces but pawns, this is
-  // somewhat related to the possibility that pawns are unstoppable.
+  // evaluate_unstoppable_pawns() scores the most advanced passed pawn. In case
+  // both players have no pieces but pawns, this is somewhat related to the
+  // possibility that pawns are unstoppable.
 
   Score evaluate_unstoppable_pawns(Color us, const EvalInfo& ei) {
 
-    Bitboard b = ei.pi->passed_pawns(us) | ei.pi->candidate_pawns(us);
+    Bitboard b = ei.pi->passed_pawns(us);
 
     return b ? Unstoppable * int(relative_rank(us, frontmost_sq(us, b))) : SCORE_ZERO;
   }