Merge pull request #9 from glinscott/master
authorMarco Costalba <mcostalba@gmail.com>
Mon, 26 Mar 2012 18:55:32 +0000 (11:55 -0700)
committerMarco Costalba <mcostalba@gmail.com>
Mon, 26 Mar 2012 18:57:27 +0000 (19:57 +0100)
Penalty for undefended rook

Almost no change at longer TC, but perhaps there
is a tiny increase....

After 17522 games at 10"+0.05
Mod vs Orig 3064 - 2967 - 11491 ELO +2

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
1  2 
src/evaluate.cpp

@@@ -678,21 -679,23 +678,24 @@@ Value do_evaluate(const Position& pos, 
  
      const Color Them = (Us == WHITE ? BLACK : WHITE);
  
--    Bitboard b;
++    Bitboard b, undefended, undefendedMinors, weakEnemies;
      Score score = SCORE_ZERO;
  
-     // Undefended minors get penalized even if not under attack
-     Bitboard undefended =  pos.pieces(Them)
-                          & (pos.pieces(BISHOP) | pos.pieces(KNIGHT))
-                          & ~ei.attackedBy[Them][0];
-     if (undefended)
-         score += single_bit(undefended) ? UndefendedMinorPenalty
-                                         : UndefendedMinorPenalty * 2;
+     // Undefended pieces get penalized even if not under attack
 -    Bitboard undefended = pos.pieces(Them) & ~ei.attackedBy[Them][0];
 -    const Bitboard undefendedMinors = undefended & (pos.pieces(BISHOP) | pos.pieces(KNIGHT));
 -    
++    undefended = pos.pieces(Them) & ~ei.attackedBy[Them][0];
++    undefendedMinors = undefended & (pos.pieces(BISHOP) | pos.pieces(KNIGHT));
++
+     if (undefendedMinors)
+         score += single_bit(undefendedMinors) ? UndefendedPiecePenalty
+                                               : UndefendedPiecePenalty * 2;
+     if (undefended & pos.pieces(ROOK))
+         score += UndefendedPiecePenalty;
  
      // Enemy pieces not defended by a pawn and under our attack
--    Bitboard weakEnemies =  pos.pieces(Them)
--                          & ~ei.attackedBy[Them][PAWN]
--                          & ei.attackedBy[Us][0];
++    weakEnemies =  pos.pieces(Them)
++                 & ~ei.attackedBy[Them][PAWN]
++                 & ei.attackedBy[Us][0];
++
      if (!weakEnemies)
          return score;