const Score KingProtector[] = { S(-3, -5), S(-4, -3), S(-3, 0), S(-1, 1) };
// Assorted bonuses and penalties used by evaluation
- const Score MinorBehindPawn = S( 16, 0);
- const Score BishopPawns = S( 8, 12);
- const Score LongRangedBishop = S( 22, 0);
- const Score RookOnPawn = S( 8, 24);
- const Score TrappedRook = S( 92, 0);
- const Score WeakQueen = S( 50, 10);
- const Score OtherCheck = S( 10, 10);
- const Score CloseEnemies = S( 7, 0);
- const Score PawnlessFlank = S( 20, 80);
- const Score ThreatByHangingPawn = S( 71, 61);
- const Score ThreatBySafePawn = S(192,175);
- const Score ThreatByRank = S( 16, 3);
- const Score Hanging = S( 48, 27);
- const Score WeakUnopposedPawn = S( 5, 25);
- const Score ThreatByPawnPush = S( 38, 22);
- const Score HinderPassedPawn = S( 7, 0);
- const Score TrappedBishopA1H1 = S( 50, 50);
+ const Score MinorBehindPawn = S( 16, 0);
+ const Score BishopPawns = S( 8, 12);
+ const Score LongRangedBishop = S( 22, 0);
+ const Score RookOnPawn = S( 8, 24);
+ const Score TrappedRook = S( 92, 0);
+ const Score WeakQueen = S( 50, 10);
+ const Score OtherCheck = S( 10, 10);
+ const Score CloseEnemies = S( 7, 0);
+ const Score PawnlessFlank = S( 20, 80);
+ const Score ThreatByHangingPawn = S( 71, 61);
+ const Score ThreatBySafePawn = S(192,175);
+ const Score ThreatByRank = S( 16, 3);
+ const Score Hanging = S( 48, 27);
+ const Score WeakUnopposedPawn = S( 5, 25);
+ const Score ThreatByPawnPush = S( 38, 22);
+ const Score ThreatByAttackOnQueen = S( 38, 22);
+ const Score HinderPassedPawn = S( 7, 0);
+ const Score TrappedBishopA1H1 = S( 50, 50);
#undef S
#undef V
template<Tracing T> template<Color Us>
void Evaluation<T>::initialize() {
- const Color Them = (Us == WHITE ? BLACK : WHITE);
- const Square Up = (Us == WHITE ? NORTH : SOUTH);
- const Square Down = (Us == WHITE ? SOUTH : NORTH);
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
+ const Direction Up = (Us == WHITE ? NORTH : SOUTH);
+ const Direction Down = (Us == WHITE ? SOUTH : NORTH);
const Bitboard LowRanks = (Us == WHITE ? Rank2BB | Rank3BB: Rank7BB | Rank6BB);
// Find our pawns on the first two ranks, and those which are blocked
attackedBy[Us][Pt] = 0;
+ if (Pt == QUEEN)
+ attackedBy[Us][QUEEN_DIAGONAL] = 0;
+
while ((s = *pl++) != SQ_NONE)
{
// Find attacked squares, including x-ray attacks for bishops and rooks
attackedBy2[Us] |= attackedBy[Us][ALL_PIECES] & b;
attackedBy[Us][ALL_PIECES] |= attackedBy[Us][Pt] |= b;
+ if (Pt == QUEEN)
+ attackedBy[Us][QUEEN_DIAGONAL] |= b & PseudoAttacks[BISHOP][s];
+
if (b & kingRing[Them])
{
kingAttackersCount[Us]++;
// Bonus for outpost squares
bb = OutpostRanks & ~pe->pawn_attacks_span(Them);
if (bb & s)
- score += Outpost[Pt == BISHOP][!!(attackedBy[Us][PAWN] & s)] * 2;
+ score += Outpost[Pt == BISHOP][bool(attackedBy[Us][PAWN] & s)] * 2;
else
{
bb &= b & ~pos.pieces(Us);
if (bb)
- score += Outpost[Pt == BISHOP][!!(attackedBy[Us][PAWN] & bb)];
+ score += Outpost[Pt == BISHOP][bool(attackedBy[Us][PAWN] & bb)];
}
// Bonus when behind a pawn
&& pos.is_chess960()
&& (s == relative_square(Us, SQ_A1) || s == relative_square(Us, SQ_H1)))
{
- Square d = pawn_push(Us) + (file_of(s) == FILE_A ? EAST : WEST);
+ Direction d = pawn_push(Us) + (file_of(s) == FILE_A ? EAST : WEST);
if (pos.piece_on(s + d) == make_piece(Us, PAWN))
score -= !pos.empty(s + d + pawn_push(Us)) ? TrappedBishopA1H1 * 4
: pos.piece_on(s + d + d) == make_piece(Us, PAWN) ? TrappedBishopA1H1 * 2
// Bonus when on an open or semi-open file
if (pe->semiopen_file(Us, file_of(s)))
- score += RookOnFile[!!pe->semiopen_file(Them, file_of(s))];
+ score += RookOnFile[bool(pe->semiopen_file(Them, file_of(s)))];
// Penalty when trapped by the king, even more if the king cannot castle
else if (mob <= 3)
template<Tracing T> template<Color Us>
Score Evaluation<T>::evaluate_king() {
- const Color Them = (Us == WHITE ? BLACK : WHITE);
- const Square Up = (Us == WHITE ? NORTH : SOUTH);
- const Bitboard Camp = (Us == WHITE ? AllSquares ^ Rank6BB ^ Rank7BB ^ Rank8BB
- : AllSquares ^ Rank1BB ^ Rank2BB ^ Rank3BB);
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
+ const Direction Up = (Us == WHITE ? NORTH : SOUTH);
+ const Bitboard Camp = (Us == WHITE ? AllSquares ^ Rank6BB ^ Rank7BB ^ Rank8BB
+ : AllSquares ^ Rank1BB ^ Rank2BB ^ Rank3BB);
const Square ksq = pos.square<KING>(Us);
- Bitboard kingOnlyDefended, undefended, b, b1, b2, safe, other;
+ Bitboard weak, b, b1, b2, safe, other;
int kingDanger;
// King shelter and enemy pawns storm
// Main king safety evaluation
if (kingAttackersCount[Them] > (1 - pos.count<QUEEN>(Them)))
{
- // Find the attacked squares which are defended only by our king...
- kingOnlyDefended = attackedBy[Them][ALL_PIECES]
- & attackedBy[Us][KING]
- & ~attackedBy2[Us];
-
- // ... and those which are not defended at all in the larger king ring
- undefended = attackedBy[Them][ALL_PIECES]
- & ~attackedBy[Us][ALL_PIECES]
- & kingRing[Us]
- & ~pos.pieces(Them);
+ // Attacked squares defended at most once by our queen or king
+ weak = attackedBy[Them][ALL_PIECES]
+ & ~attackedBy2[Us]
+ & (attackedBy[Us][KING] | attackedBy[Us][QUEEN] | ~attackedBy[Us][ALL_PIECES]);
// Initialize the 'kingDanger' variable, which will be transformed
// later into a king danger score. The initial value is based on the
// the quality of the pawn shelter (current 'score' value).
kingDanger = kingAttackersCount[Them] * kingAttackersWeight[Them]
+ 102 * kingAdjacentZoneAttacksCount[Them]
- + 191 * popcount(kingOnlyDefended | undefended)
- + 143 * !!pos.pinned_pieces(Us)
+ + 191 * popcount(kingRing[Us] & weak)
+ + 143 * bool(pos.pinned_pieces(Us))
- 848 * !pos.count<QUEEN>(Them)
- 9 * mg_value(score) / 8
+ 40;
// Analyse the safe enemy's checks which are possible on next move
safe = ~pos.pieces(Them);
- safe &= ~attackedBy[Us][ALL_PIECES] | (kingOnlyDefended & attackedBy2[Them]);
+ safe &= ~attackedBy[Us][ALL_PIECES] | (weak & attackedBy2[Them]);
b1 = pos.attacks_from< ROOK>(ksq);
b2 = pos.attacks_from<BISHOP>(ksq);
// Enemy queen safe checks
- if ((b1 | b2) & attackedBy[Them][QUEEN] & safe)
+ if ((b1 | b2) & attackedBy[Them][QUEEN] & safe & ~attackedBy[Us][QUEEN])
kingDanger += QueenCheck;
- // For minors and rooks, also consider the square safe if attacked twice,
- // and only defended by our queen.
- safe |= attackedBy2[Them]
- & ~(attackedBy2[Us] | pos.pieces(Them))
- & attackedBy[Us][QUEEN];
-
// Some other potential checks are also analysed, even from squares
// currently occupied by the opponent own pieces, as long as the square
// is not attacked by our pawns, and is not occupied by a blocked pawn.
template<Tracing T> template<Color Us>
Score Evaluation<T>::evaluate_threats() {
- const Color Them = (Us == WHITE ? BLACK : WHITE);
- const Square Up = (Us == WHITE ? NORTH : SOUTH);
- const Square Left = (Us == WHITE ? NORTH_WEST : SOUTH_EAST);
- const Square Right = (Us == WHITE ? NORTH_EAST : SOUTH_WEST);
- const Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB);
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
+ const Direction Up = (Us == WHITE ? NORTH : SOUTH);
+ const Direction Left = (Us == WHITE ? NORTH_WEST : SOUTH_EAST);
+ const Direction Right = (Us == WHITE ? NORTH_EAST : SOUTH_WEST);
+ const Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB);
Bitboard b, weak, defended, stronglyProtected, safeThreats;
Score score = SCORE_ZERO;
score += ThreatByPawnPush * popcount(b);
+ // Add a bonus for safe slider attack threats on opponent queen
+ safeThreats = ~pos.pieces(Us) & ~attackedBy2[Them] & attackedBy2[Us];
+ b = (attackedBy[Us][BISHOP] & attackedBy[Them][QUEEN_DIAGONAL])
+ | (attackedBy[Us][ROOK ] & attackedBy[Them][QUEEN] & ~attackedBy[Them][QUEEN_DIAGONAL]);
+
+ score += ThreatByAttackOnQueen * popcount(b & safeThreats);
+
if (T)
Trace::add(THREAT, Us, score);
template<Tracing T> template<Color Us>
Score Evaluation<T>::evaluate_passed_pawns() {
- const Color Them = (Us == WHITE ? BLACK : WHITE);
- const Square Up = (Us == WHITE ? NORTH : SOUTH);
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
+ const Direction Up = (Us == WHITE ? NORTH : SOUTH);
Bitboard b, bb, squaresToQueen, defendedSquares, unsafeSquares;
Score score = SCORE_ZERO;
// Initialize score by reading the incrementally updated scores included in
// the position object (material + piece square tables) and the material
// imbalance. Score is computed internally from the white point of view.
- Score score = pos.psq_score() + me->imbalance();
+ Score score = pos.psq_score() + me->imbalance() + Eval::Contempt;
// Probe the pawn hash table
pe = Pawns::probe(pos);
} // namespace
+Score Eval::Contempt = SCORE_ZERO;
/// evaluate() is the evaluator for the outer world. It returns a static evaluation
/// of the position from the point of view of the side to move.