Score score = SCORE_ZERO;
// Undefended minors get penalized even if not under attack
- undefendedMinors = pos.pieces(Them)
- & (pos.pieces(BISHOP) | pos.pieces(KNIGHT))
+ undefendedMinors = pos.pieces(Them, BISHOP, KNIGHT)
& ~ei.attackedBy[Them][ALL_PIECES];
if (undefendedMinors)
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));
+ // If there aren't enemy attacks huge bonus, a bit smaller if at
+ // least block square is not attacked, otherwise smallest bonus.
+ int k = !unsafeSquares ? 15 : !(unsafeSquares & blockSq) ? 9 : 3;
+
+ // Big bonus if the path to queen is fully defended, a bit less
+ // if at least block square is defended.
+ if (defendedSquares == squaresToQueen)
+ k += 6;
+
+ else if (defendedSquares & blockSq)
+ k += (unsafeSquares & defendedSquares) == unsafeSquares ? 4 : 2;
+
+ mbonus += Value(k * rr), ebonus += Value(k * rr);
}
} // rr != 0