SEE Pruning Tweak (#2183)

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index d1a8ffd31fb4ab954ed3849bfa927d58bde5c3bf..30c22a8e65b340103fda85698f31d91e55dfcc97 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
@@ -141,7 +141,7 @@ namespace {
   constexpr Score KnightOnQueen      = S( 16, 12);
   constexpr Score LongDiagonalBishop = S( 45,  0);
   constexpr Score MinorBehindPawn    = S( 18,  3);
-  constexpr Score Outpost            = S(  9,  3);
+  constexpr Score Outpost            = S( 36, 12);
   constexpr Score PawnlessFlank      = S( 17, 95);
   constexpr Score RestrictedPiece    = S(  7,  7);
   constexpr Score RookOnPawn         = S( 10, 32);
@@ -305,14 +305,12 @@ namespace {
         if (Pt == BISHOP || Pt == KNIGHT)
         {
             // Bonus if piece is on an outpost square or can reach one
-            bb = OutpostRanks & ~pe->pawn_attacks_span(Them);
+            bb = OutpostRanks & attackedBy[Us][PAWN] & ~pe->pawn_attacks_span(Them);
             if (bb & s)
-                score += Outpost * (Pt == KNIGHT ? 4 : 2)
-                                 * ((attackedBy[Us][PAWN] & s) ? 2 : 1);
+                score += Outpost * (Pt == KNIGHT ? 2 : 1);
 
-            else if (bb &= b & ~pos.pieces(Us))
-                score += Outpost * (Pt == KNIGHT ? 2 : 1)
-                                 * ((attackedBy[Us][PAWN] & bb) ? 2 : 1);
+            else if (bb & b & ~pos.pieces(Us))
+                score += Outpost / (Pt == KNIGHT ? 1 : 2);
 
             // Knight and Bishop bonus for being right behind a pawn
             if (shift<Down>(pos.pieces(PAWN)) & s)
@@ -357,8 +355,8 @@ 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)
@@ -649,7 +647,7 @@ namespace {
                 // in the pawn's path attacked or occupied by the enemy.
                 defendedSquares = unsafeSquares = squaresToQueen = forward_file_bb(Us, s);
 
-                bb = forward_file_bb(Them, s) & pos.pieces(ROOK, QUEEN) & pos.attacks_from<ROOK>(s);
+                bb = forward_file_bb(Them, s) & pos.pieces(ROOK, QUEEN);
 
                 if (!(pos.pieces(Us) & bb))
                     defendedSquares &= attackedBy[Us][ALL_PIECES];
@@ -661,13 +659,9 @@ 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 +807,7 @@ 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