Simplify k-value for passers. Bench: 3854907 (#2182)

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index dff84df3750e29ea5217000d6374109ad7fc1d0b..8c1b0b086d30d87f0a943756908d9f072462a3ae 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -74,7 +74,7 @@ using namespace Trace;
 namespace {
 
   // Threshold for lazy and space evaluation
-  constexpr Value LazyThreshold  = Value(1500);
+  constexpr Value LazyThreshold  = Value(1400);
   constexpr Value SpaceThreshold = Value(12222);
 
   // KingAttackWeights[PieceType] contains king attack weights by piece type
@@ -357,8 +357,8 @@ namespace {
                 score += RookOnPawn * popcount(pos.pieces(Them, PAWN) & PseudoAttacks[ROOK][s]);
 
             // Bonus for rook on an open or semi-open file
-            if (pos.is_semiopen_file(Us, file_of(s)))
-                score += RookOnFile[bool(pos.is_semiopen_file(Them, file_of(s)))];
+            if (pos.is_on_semiopen_file(Us, s))
+                score += RookOnFile[bool(pos.is_on_semiopen_file(Them, s))];
 
             // Penalty when trapped by the king, even more if the king cannot castle
             else if (mob <= 3)
@@ -661,13 +661,9 @@ namespace {
                 // assign a smaller bonus if the block square isn't attacked.
                 int k = !unsafeSquares ? 20 : !(unsafeSquares & blockSq) ? 9 : 0;
 
-                // If the path to the queen is fully defended, assign a big bonus.
-                // Otherwise assign a smaller bonus if the block square is defended.
-                if (defendedSquares == squaresToQueen)
-                    k += 6;
-
-                else if (defendedSquares & blockSq)
-                    k += 4;
+                // Assign a larger bonus if the block square is defended.
+                if (defendedSquares & blockSq)
+                    k += 5;
 
                 bonus += make_score(k * w, k * w);
             }
@@ -813,7 +809,7 @@ namespace {
 
     // Early exit if score is high
     Value v = (mg_value(score) + eg_value(score)) / 2;
-    if (abs(v) > LazyThreshold)
+    if (abs(v) > (LazyThreshold + pos.non_pawn_material() / 64))
        return pos.side_to_move() == WHITE ? v : -v;
 
     // Main evaluation begins here