// 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);
+
// 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
// based on how many squares inside this area are safe and available for
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();
& (pos.pieces(BISHOP) | pos.pieces(KNIGHT))
& ~ei.attackedBy[Them][0];
if (undefended)
- score += make_score(25, 10) * popcount<Max15>(undefended);
+ score += single_bit(undefended) ? UndefendedMinorPenalty
+ : UndefendedMinorPenalty * 2;
// Enemy pieces not defended by a pawn and under our attack
Bitboard weakEnemies = pos.pieces(Them)