Passed pawn eval

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 6f572f4e4b28854e3658d120b9766a66d572e5b5..c2f025fccd87047034fea47ad8d8984b27b1b2ad 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -642,17 +642,17 @@ Value do_evaluate(const Position& pos, Value& margin) {
                     score += RookHalfOpenFileBonus;
             }
 
-            // Penalize rooks which are trapped inside a king. Penalize more if
-            // king has lost right to castle.
             if (mob > 6 || ei.pi->file_is_half_open(Us, f))
                 continue;
 
             ksq = pos.king_square(Us);
-            bool left = file_of(ksq) < FILE_E;
 
-            if (   ((left && file_of(s) < file_of(ksq)) || (!left && file_of(s) > file_of(ksq)))
-                && (relative_rank(Us, ksq) == RANK_1 && rank_of(ksq) == rank_of(s))
-                && (!ei.pi->has_open_file_on_side(Us, file_of(ksq), left)))
+            // Penalize rooks which are trapped inside a king. Penalize more if
+            // king has lost right to castle.
+            if (   ((file_of(ksq) < FILE_E) == (file_of(s) < file_of(ksq)))
+                && rank_of(ksq) == rank_of(s)
+                && relative_rank(Us, ksq) == RANK_1
+                && !ei.pi->has_open_file_on_side(Us, file_of(ksq), file_of(ksq) < FILE_E))
                 score -= make_score(pos.can_castle(Us) ? (TrappedRookPenalty - mob * 16) / 2
                                                        : (TrappedRookPenalty - mob * 16), 0);
         }
@@ -900,16 +900,30 @@ Value do_evaluate(const Position& pos, Value& margin) {
                 else
                     unsafeSquares = squaresToQueen & (ei.attackedBy[Them][ALL_PIECES] | pos.pieces(Them));
 
-                // If there aren't enemy attacks or pieces along the path to queen give
-                // huge bonus. Even bigger if we protect the pawn's path.
-                if (!unsafeSquares)
-                    ebonus += Value(rr * (squaresToQueen == defendedSquares ? 17 : 15));
-                else
-                    // OK, there are enemy attacks or pieces (but not pawns). Are those
-                    // squares which are attacked by the enemy also attacked by us ?
-                    // If yes, big bonus (but smaller than when there are no enemy attacks),
-                    // if no, somewhat smaller bonus.
-                    ebonus += Value(rr * ((unsafeSquares & defendedSquares) == unsafeSquares ? 13 : 8));
+                // Default bonus for the empty square in front
+                int bonusMultiplier = 3;
+
+                if ((defendedSquares & SquareBB[blockSq]) != 0)
+                {
+                    // Defending the square in front
+                    bonusMultiplier += 2;
+                    if ((unsafeSquares & defendedSquares) == unsafeSquares)
+                        // Defending all the attacked squares
+                        // bigger bonus if we are defending everything
+                        bonusMultiplier += (squaresToQueen == defendedSquares) ? 4 : 2;
+                }
+
+                if ((unsafeSquares & SquareBB[blockSq]) == 0)
+                {
+                    // The square infront isn't attacked
+                    bonusMultiplier += 6;
+                    if (!unsafeSquares)
+                        bonusMultiplier += 6;
+                }
+
+                Value bonus = Value(rr * bonusMultiplier);
+                ebonus += bonus;
+                mbonus += bonus;
             }
         } // rr != 0