const Score KingProtector[] = { S(3, 5), S(4, 3), S(3, 0), S(1, -1) };
// Assorted bonuses and penalties
- const Score BishopPawns = S( 8, 12);
- const Score CloseEnemies = S( 7, 0);
- const Score Hanging = S( 52, 30);
- const Score HinderPassedPawn = S( 8, 1);
- const Score LongRangedBishop = S( 22, 0);
- const Score MinorBehindPawn = S( 16, 0);
- const Score PawnlessFlank = S( 20, 80);
- const Score RookOnPawn = S( 8, 24);
- const Score ThreatByPawnPush = S( 47, 26);
- const Score ThreatByRank = S( 16, 3);
- const Score ThreatBySafePawn = S(175,168);
- const Score ThreatOnQueen = S( 42, 21);
- const Score TrappedBishopA1H1 = S( 50, 50);
- const Score TrappedRook = S( 92, 0);
- const Score WeakQueen = S( 50, 10);
- const Score WeakUnopposedPawn = S( 5, 25);
+ const Score BishopPawns = S( 8, 12);
+ const Score CloseEnemies = S( 7, 0);
+ const Score Connectivity = S( 3, 1);
+ const Score CorneredBishop = S( 50, 50);
+ const Score Hanging = S( 52, 30);
+ const Score HinderPassedPawn = S( 8, 1);
+ const Score KnightOnQueen = S( 21, 11);
+ const Score LongDiagonalBishop = S( 22, 0);
+ const Score MinorBehindPawn = S( 16, 0);
+ const Score PawnlessFlank = S( 20, 80);
+ const Score RookOnPawn = S( 8, 24);
+ const Score SliderOnQueen = S( 42, 21);
+ const Score ThreatByPawnPush = S( 47, 26);
+ const Score ThreatByRank = S( 16, 3);
+ const Score ThreatBySafePawn = S(175,168);
+ const Score TrappedRook = S( 92, 0);
+ const Score WeakQueen = S( 50, 10);
+ const Score WeakUnopposedPawn = S( 5, 25);
#undef S
// attackedBy[color][piece type] is a bitboard representing all squares
// attacked by a given color and piece type. Special "piece types" which
- // are also calculated are QUEEN_DIAGONAL and ALL_PIECES.
+ // is also calculated is ALL_PIECES.
Bitboard attackedBy[COLOR_NB][PIECE_TYPE_NB];
// attackedBy2[color] are the squares attacked by 2 pieces of a given color,
// which attack a square in the kingRing of the enemy king.
int kingAttackersCount[COLOR_NB];
- // kingAttackersWeight[color] is the sum of the "weights" of the pieces of the
- // given color which attack a square in the kingRing of the enemy king. The
- // weights of the individual piece types are given by the elements in the
- // KingAttackWeights array.
+ // kingAttackersWeight[color] is the sum of the "weights" of the pieces of
+ // the given color which attack a square in the kingRing of the enemy king.
+ // The weights of the individual piece types are given by the elements in
+ // the KingAttackWeights array.
int kingAttackersWeight[COLOR_NB];
- // kingAdjacentZoneAttacksCount[color] is the number of attacks by the given
- // color to squares directly adjacent to the enemy king. Pieces which attack
- // more than one square are counted multiple times. For instance, if there is
+ // kingAttacksCount[color] is the number of attacks by the given color to
+ // squares directly adjacent to the enemy king. Pieces which attack more
+ // than one square are counted multiple times. For instance, if there is
// a white knight on g5 and black's king is on g8, this white knight adds 2
- // to kingAdjacentZoneAttacksCount[WHITE].
- int kingAdjacentZoneAttacksCount[COLOR_NB];
+ // to kingAttacksCount[WHITE].
+ int kingAttacksCount[COLOR_NB];
};
kingRing[Us] |= shift<Up>(kingRing[Us]);
kingAttackersCount[Them] = popcount(attackedBy[Us][KING] & pe->pawn_attacks(Them));
- kingAdjacentZoneAttacksCount[Them] = kingAttackersWeight[Them] = 0;
+ kingAttacksCount[Them] = kingAttackersWeight[Them] = 0;
}
else
kingRing[Us] = kingAttackersCount[Them] = 0;
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
attackedBy[Us][Pt] |= b;
attackedBy[Us][ALL_PIECES] |= b;
- if (Pt == QUEEN)
- attackedBy[Us][QUEEN_DIAGONAL] |= b & PseudoAttacks[BISHOP][s];
-
if (b & kingRing[Them])
{
kingAttackersCount[Us]++;
kingAttackersWeight[Us] += KingAttackWeights[Pt];
- kingAdjacentZoneAttacksCount[Us] += popcount(b & attackedBy[Them][KING]);
+ kingAttacksCount[Us] += popcount(b & attackedBy[Them][KING]);
}
int mob = popcount(b & mobilityArea[Us]);
// Bonus for bishop on a long diagonal which can "see" both center squares
if (more_than_one(Center & (attacks_bb<BISHOP>(s, pos.pieces(PAWN)) | s)))
- score += LongRangedBishop;
+ score += LongDiagonalBishop;
}
// An important Chess960 pattern: A cornered bishop blocked by a friendly
{
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
- : TrappedBishopA1H1;
+ score -= !pos.empty(s + d + pawn_push(Us)) ? CorneredBishop * 4
+ : pos.piece_on(s + d + d) == make_piece(Us, PAWN) ? CorneredBishop * 2
+ : CorneredBishop;
}
}
pinned = pos.blockers_for_king(Us) & pos.pieces(Us);
kingDanger += kingAttackersCount[Them] * kingAttackersWeight[Them]
- + 102 * kingAdjacentZoneAttacksCount[Them]
+ + 102 * kingAttacksCount[Them]
+ 191 * popcount(kingRing[Us] & weak)
+ 143 * popcount(pinned | unsafeChecks)
- 848 * !pos.count<QUEEN>(Them)
if (!(pos.pieces(PAWN) & kf))
score -= PawnlessFlank;
- // Find the squares that opponent attacks in our king flank, and the squares
+ // 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];
score += ThreatByPawnPush * popcount(b);
- // Bonus for safe slider threats on the next move toward enemy 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]);
+ // Bonus for threats on the next moves against enemy queen
+ if (pos.count<QUEEN>(Them) == 1)
+ {
+ Square s = pos.square<QUEEN>(Them);
+ safeThreats = mobilityArea[Us] & ~stronglyProtected;
+
+ b = attackedBy[Us][KNIGHT] & pos.attacks_from<KNIGHT>(s);
+
+ score += KnightOnQueen * popcount(b & safeThreats);
+
+ b = (attackedBy[Us][BISHOP] & pos.attacks_from<BISHOP>(s))
+ | (attackedBy[Us][ROOK ] & pos.attacks_from<ROOK >(s));
+
+ score += SliderOnQueen * popcount(b & safeThreats & attackedBy2[Us]);
+ }
- score += ThreatOnQueen * popcount(b & safeThreats);
+ // Connectivity: ensure that knights, bishops, rooks, and queens are protected
+ b = (pos.pieces(Us) ^ pos.pieces(Us, PAWN, KING)) & attackedBy[Us][ALL_PIECES];
+ score += Connectivity * popcount(b);
if (T)
Trace::add(THREAT, Us, score);
+ 8 * pe->pawn_asymmetry()
+ 12 * pos.count<PAWN>()
+ 16 * pawnsOnBothFlanks
+ + 48 * !pos.non_pawn_material()
-136 ;
// Now apply the bonus: note that we find the attacking side by extracting
projects / stockfish / blobdiff