Bonus for rook/queen attacking pawns on same rank

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 3b70a950a66db5ee16f9f28e050b80b5864450b0..b5b51d2cdc6ddecd295b0d1474b683436bbe1a82 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -138,7 +138,7 @@ namespace {
     {}, {},
     { S(0, 0), S( 7, 39), S( 0,  0), S(24, 49), S(41,100), S(41,100) }, // KNIGHT
     { S(0, 0), S( 7, 39), S(24, 49), S( 0,  0), S(41,100), S(41,100) }, // BISHOP
-    { S(0, 0), S(-1, 29), S(15, 49), S(15, 49), S( 0,  0), S(24, 49) }, // ROOK
+    { S(0, 0), S( 0, 22), S(15, 49), S(15, 49), S( 0,  0), S(24, 49) }, // ROOK
     { S(0, 0), S(15, 39), S(15, 39), S(15, 39), S(15, 39), S( 0,  0) }  // QUEEN
   };
 
@@ -153,12 +153,16 @@ namespace {
   // Bonus for having the side to move (modified by Joona Kiiski)
   const Score Tempo = make_score(24, 11);
 
-  // Rooks and queens on the 7th rank (modified by Joona Kiiski)
-  const Score RookOn7thBonus  = make_score(47, 98);
-  const Score QueenOn7thBonus = make_score(27, 54);
+  // Rooks and queens on the 7th rank
+  const Score RookOn7thBonus  = make_score(3, 20);
+  const Score QueenOn7thBonus = make_score(1,  8);
+
+  // Rooks and queens attacking pawns on the same rank
+  const Score RookOnPawnBonus  = make_score(3, 48);
+  const Score QueenOnPawnBonus = make_score(1, 40);
 
   // Rooks on open files (modified by Joona Kiiski)
-  const Score RookOpenFileBonus = make_score(43, 21);
+  const Score RookOpenFileBonus     = make_score(43, 21);
   const Score RookHalfOpenFileBonus = make_score(19, 10);
 
   // Penalty for rooks trapped inside a friendly king which has lost the
@@ -435,8 +439,8 @@ Value do_evaluate(const Position& pos, Value& margin) {
       && sf == SCALE_FACTOR_NORMAL)
   {
       // Only the two bishops ?
-      if (   pos.non_pawn_material(WHITE) == BishopValueMidgame
-          && pos.non_pawn_material(BLACK) == BishopValueMidgame)
+      if (   pos.non_pawn_material(WHITE) == BishopValueMg
+          && pos.non_pawn_material(BLACK) == BishopValueMg)
       {
           // Check for KBP vs KB with only a single pawn that is almost
           // certainly a draw or at least two pawns.
@@ -492,7 +496,7 @@ Value do_evaluate(const Position& pos, Value& margin) {
 
     // Init king safety tables only if we are going to use them
     if (   pos.piece_count(Us, QUEEN)
-        && pos.non_pawn_material(Us) >= QueenValueMidgame + RookValueMidgame)
+        && pos.non_pawn_material(Us) >= QueenValueMg + RookValueMg)
     {
         ei.kingRing[Them] = (b | (Us == WHITE ? b >> 8 : b << 8));
         b &= ei.attackedBy[Us][PAWN];
@@ -595,12 +599,18 @@ Value do_evaluate(const Position& pos, Value& margin) {
             && !(pos.pieces(Them, PAWN) & attack_span_mask(Us, s)))
             score += evaluate_outposts<Piece, Us>(pos, ei, s);
 
-        // Queen or rook on 7th rank
-        if (  (Piece == ROOK || Piece == QUEEN)
-            && relative_rank(Us, s) == RANK_7
-            && relative_rank(Us, pos.king_square(Them)) == RANK_8)
+        if ((Piece == ROOK || Piece == QUEEN) && relative_rank(Us, s) >= RANK_5)
         {
-            score += (Piece == ROOK ? RookOn7thBonus : QueenOn7thBonus);
+            // Major piece on 7th rank
+            if (   relative_rank(Us, s) == RANK_7
+                && relative_rank(Us, pos.king_square(Them)) == RANK_8)
+                score += (Piece == ROOK ? RookOn7thBonus : QueenOn7thBonus);
+
+            // Major piece attacking pawns on the same rank
+            Bitboard pawns = pos.pieces(Them, PAWN) & rank_bb(s);
+            if (pawns)
+                score += (Piece == ROOK ? RookOnPawnBonus
+                                        : QueenOnPawnBonus) * popcount<Max15>(pawns);
         }
 
         // Special extra evaluation for bishops
@@ -938,7 +948,7 @@ Value do_evaluate(const Position& pos, Value& margin) {
         // value if the other side has a rook or queen.
         if (file_of(s) == FILE_A || file_of(s) == FILE_H)
         {
-            if (pos.non_pawn_material(Them) <= KnightValueMidgame)
+            if (pos.non_pawn_material(Them) <= KnightValueMg)
                 ebonus += ebonus / 4;
             else if (pos.pieces(Them, ROOK, QUEEN))
                 ebonus -= ebonus / 4;
@@ -1172,7 +1182,7 @@ Value do_evaluate(const Position& pos, Value& margin) {
   // A couple of little helpers used by tracing code, to_cp() converts a value to
   // a double in centipawns scale, trace_add() stores white and black scores.
 
-  double to_cp(Value v) { return double(v) / double(PawnValueMidgame); }
+  double to_cp(Value v) { return double(v) / double(PawnValueMg); }
 
   void trace_add(int idx, Score wScore, Score bScore) {