constexpr Score LongDiagonalBishop = S( 22, 0);
constexpr Score MinorBehindPawn = S( 16, 0);
constexpr Score Overload = S( 13, 6);
- constexpr Score PawnlessFlank = S( 20, 80);
+ constexpr Score PawnlessFlank = S( 19, 84);
constexpr Score RookOnPawn = S( 8, 24);
constexpr Score SliderOnQueen = S( 42, 21);
constexpr Score ThreatByKing = S( 23, 76);
: AllSquares ^ Rank1BB ^ Rank2BB ^ Rank3BB);
const Square ksq = pos.square<KING>(Us);
- Bitboard weak, b, b1, b2, safe, unsafeChecks;
+ Bitboard kingFlank, weak, b, b1, b2, safe, unsafeChecks;
// King shelter and enemy pawns storm
Score score = pe->king_safety<Us>(pos, ksq);
+ // Find the squares that opponent attacks in our king flank, and the squares
+ // which are attacked twice in that flank but not defended by our pawns.
+ kingFlank = KingFlank[file_of(ksq)];
+ b1 = attackedBy[Them][ALL_PIECES] & kingFlank & Camp;
+ b2 = b1 & attackedBy2[Them] & ~attackedBy[Us][PAWN];
+
+ int tropism = popcount(b1) + popcount(b2);
+
// Main king safety evaluation
if (kingAttackersCount[Them] > 1 - pos.count<QUEEN>(Them))
{
+ 69 * kingAttacksCount[Them]
+ 185 * popcount(kingRing[Us] & weak)
+ 129 * popcount(pos.blockers_for_king(Us) | unsafeChecks)
+ + 4 * tropism
- 873 * !pos.count<QUEEN>(Them)
- 6 * mg_value(score) / 8
- - 2 ;
+ - 30;
// Transform the kingDanger units into a Score, and subtract it from the evaluation
if (kingDanger > 0)
}
}
- Bitboard kf = KingFlank[file_of(ksq)];
-
// Penalty when our king is on a pawnless flank
- if (!(pos.pieces(PAWN) & kf))
+ if (!(pos.pieces(PAWN) & kingFlank))
score -= PawnlessFlank;
- // Find the squares that opponent attacks in our king flank, and the squares
- // which are attacked twice in that flank but not defended by our pawns.
- b1 = attackedBy[Them][ALL_PIECES] & kf & Camp;
- b2 = b1 & attackedBy2[Them] & ~attackedBy[Us][PAWN];
-
- // King tropism, to anticipate slow motion attacks on our king
- score -= CloseEnemies * (popcount(b1) + popcount(b2));
+ // King tropism bonus, to anticipate slow motion attacks on our king
+ score -= CloseEnemies * tropism;
if (T)
Trace::add(KING, Us, score);
template<Tracing T> template<Color Us>
Score Evaluation<T>::space() const {
+ if (pos.non_pawn_material() < SpaceThreshold)
+ return SCORE_ZERO;
+
constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
constexpr Bitboard SpaceMask =
Us == WHITE ? CenterFiles & (Rank2BB | Rank3BB | Rank4BB)
: CenterFiles & (Rank7BB | Rank6BB | Rank5BB);
- if (pos.non_pawn_material() < SpaceThreshold)
- return SCORE_ZERO;
-
// Find the available squares for our pieces inside the area defined by SpaceMask
Bitboard safe = SpaceMask
& ~pos.pieces(Us, PAWN)