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

diff --combined src/evaluate.cpp
index b2cae94c0e30de30956bfa6d9a92107e1b1e0db1,c03aa99f51940f0f0ec96fcbc7dce8b5ec9b4e69..6e515d88998f612c8dea4669e3d577cb9802636b
@@@ -167,8 -167,8 +167,8 @@@ namespace 
    // happen in Chess960 games.
    const Score TrappedBishopA1H1Penalty = make_score(100, 100);
  
-   // Penalty for a minor piece that is not defended by anything
-   const Score UndefendedMinorPenalty = make_score(25, 10);
+   // Penalty for BNR that is not defended by anything
+   const Score UndefendedPiecePenalty = make_score(25, 10);
  
    // The SpaceMask[Color] contains the area of the board which is considered
    // by the space evaluation. In the middle game, each side is given a bonus
@@@ -357,12 -357,13 +357,12 @@@ namespace 
  template<bool Trace>
  Value do_evaluate(const Position& pos, Value& margin) {
  
 +  assert(!pos.in_check());
 +
    EvalInfo ei;
    Value margins[2];
    Score score, mobilityWhite, mobilityBlack;
  
 -  assert(pos.thread() >= 0 && pos.thread() < MAX_THREADS);
 -  assert(!pos.in_check());
 -
    // Initialize score by reading the incrementally updated scores included
    // in the position object (material + piece square tables).
    score = pos.value();
  
      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;