constexpr Score ReachableOutpost = S( 31, 22);
constexpr Score PassedFile = S( 11, 8);
constexpr Score PawnlessFlank = S( 17, 95);
+ constexpr Score QueenInfiltration = S( -2, 14);
constexpr Score RestrictedPiece = S( 7, 7);
constexpr Score RookOnKingRing = S( 16, 0);
- constexpr Score RookOnQueenFile = S( 5, 9);
- constexpr Score SliderOnQueen = S( 59, 18);
+ constexpr Score RookOnQueenFile = S( 6, 11);
+ constexpr Score SliderOnQueen = S( 60, 18);
constexpr Score ThreatByKing = S( 24, 89);
constexpr Score ThreatByPawnPush = S( 48, 39);
constexpr Score ThreatBySafePawn = S(173, 94);
constexpr Score TrappedRook = S( 55, 13);
- constexpr Score WeakQueen = S( 51, 14);
- constexpr Score WeakQueenProtection = S( 15, 0);
+ constexpr Score WeakQueen = S( 56, 15);
+ constexpr Score WeakQueenProtection = S( 14, 0);
#undef S
Bitboard queenPinners;
if (pos.slider_blockers(pos.pieces(Them, ROOK, BISHOP), s, queenPinners))
score -= WeakQueen;
+
+ // Bonus for queen on weak square in enemy camp
+ if (relative_rank(Us, s) > RANK_4 && (~pe->pawn_attacks_span(Them) & s))
+ score += QueenInfiltration;
}
}
if (T)
}
- // Evaluation::space() computes the space evaluation for a given side. The
- // space evaluation is a simple bonus based on the number of safe squares
- // available for minor pieces on the central four files on ranks 2--4. Safe
- // squares one, two or three squares behind a friendly pawn are counted
- // twice. Finally, the space bonus is multiplied by a weight. The aim is to
- // improve play on game opening.
+ // Evaluation::space() computes a space evaluation for a given side, aiming to improve game
+ // play in the opening. It is based on the number of safe squares on the 4 central files
+ // on ranks 2 to 4. Completely safe squares behind a friendly pawn are counted twice.
+ // Finally, the space bonus is multiplied by a weight which decreases according to occupancy.
template<Tracing T> template<Color Us>
Score Evaluation<T>::space() const {
+ // Early exit if, for example, both queens or 6 minor pieces have been exchanged
if (pos.non_pawn_material() < SpaceThreshold)
return SCORE_ZERO;
+ 24 * infiltration
+ 51 * !pos.non_pawn_material()
- 43 * almostUnwinnable
- - 2 * pos.rule50_count()
-110 ;
Value mg = mg_value(score);
Trace::add(MOBILITY, mobility[WHITE], mobility[BLACK]);
}
+ // Evaluation grain
+ v = (v / 16) * 16;
+
// Side to move point of view
- return (pos.side_to_move() == WHITE ? v : -v) + Tempo;
+ v = (pos.side_to_move() == WHITE ? v : -v) + Tempo;
+
+ // Damp down the evaluation linearly when shuffling
+ v = v * (100 - pos.rule50_count()) / 100;
+
+ return v;
}
} // namespace