constexpr Value SpaceThreshold = Value(12222);
// KingAttackWeights[PieceType] contains king attack weights by piece type
- constexpr int KingAttackWeights[PIECE_TYPE_NB] = { 0, 0, 78, 56, 45, 11 };
+ constexpr int KingAttackWeights[PIECE_TYPE_NB] = { 0, 0, 77, 55, 44, 10 };
// Penalties for enemy's safe checks
constexpr int QueenSafeCheck = 780;
S(0, 0), S(0, 24), S(38, 71), S(38, 61), S(0, 38), S(36, 38)
};
- // ThreatByKing[on one/on many] contains bonuses for king attacks on
- // pawns or pieces which are not pawn-defended.
- constexpr Score ThreatByKing[] = { S(3, 65), S(9, 145) };
-
// PassedRank[Rank] contains a bonus according to the rank of a passed pawn
constexpr Score PassedRank[RANK_NB] = {
- S(0, 0), S(5, 7), S(5, 13), S(18, 23), S(74, 58), S(164, 166), S(268, 243)
+ S(0, 0), S(5, 18), S(12, 23), S(10, 31), S(57, 62), S(163, 167), S(271, 250)
};
// PassedFile[File] contains a bonus according to the file of a passed pawn
constexpr Score PassedFile[FILE_NB] = {
- S( 15, 7), S(-5, 14), S( 1, -5), S(-22,-11),
- S(-22,-11), S( 1, -5), S(-5, 14), S( 15, 7)
+ S( -1, 7), S( 0, 9), S(-9, -8), S(-30,-14),
+ S(-30,-14), S(-9, -8), S( 0, 9), S( -1, 7)
};
// PassedDanger[Rank] contains a term to weight the passed score
- constexpr int PassedDanger[RANK_NB] = { 0, 0, 0, 3, 6, 12, 21 };
-
- // KingProtector[PieceType-2] contains a penalty according to distance from king
- constexpr Score KingProtector[] = { S(3, 5), S(4, 3), S(3, 0), S(1, -1) };
+ constexpr int PassedDanger[RANK_NB] = { 0, 0, 0, 3, 7, 11, 20 };
// Assorted bonuses and penalties
- constexpr Score BishopPawns = S( 3, 5);
- constexpr Score CloseEnemies = S( 7, 0);
- constexpr Score Connectivity = S( 3, 1);
+ constexpr Score BishopPawns = S( 3, 7);
+ constexpr Score CloseEnemies = S( 6, 0);
constexpr Score CorneredBishop = S( 50, 50);
constexpr Score Hanging = S( 52, 30);
- constexpr Score HinderPassedPawn = S( 8, 1);
+ constexpr Score HinderPassedPawn = S( 4, 0);
+ constexpr Score KingProtector = S( 6, 6);
constexpr Score KnightOnQueen = S( 21, 11);
constexpr Score LongDiagonalBishop = S( 22, 0);
constexpr Score MinorBehindPawn = S( 16, 0);
- constexpr Score Overload = S( 10, 5);
+ constexpr Score Overload = S( 16, 7);
constexpr Score PawnlessFlank = S( 20, 80);
constexpr Score RookOnPawn = S( 8, 24);
constexpr Score SliderOnQueen = S( 42, 21);
- constexpr Score ThreatByPawnPush = S( 47, 26);
+ constexpr Score ThreatByKing = S( 23, 76);
+ constexpr Score ThreatByPawnPush = S( 45, 40);
constexpr Score ThreatByRank = S( 16, 3);
- constexpr Score ThreatBySafePawn = S(175,168);
+ constexpr Score ThreatBySafePawn = S(173,102);
constexpr Score TrappedRook = S( 92, 0);
constexpr Score WeakQueen = S( 50, 10);
- constexpr Score WeakUnopposedPawn = S( 5, 25);
+ constexpr Score WeakUnopposedPawn = S( 5, 29);
#undef S
else if (file_of(pos.square<KING>(Us)) == FILE_A)
kingRing[Us] |= shift<EAST>(kingRing[Us]);
- kingAttackersCount[Them] = popcount(attackedBy[Us][KING] & pe->pawn_attacks(Them));
+ kingAttackersCount[Them] = popcount(kingRing[Us] & pe->pawn_attacks(Them));
kingAttacksCount[Them] = kingAttackersWeight[Them] = 0;
}
else
mobility[Us] += MobilityBonus[Pt - 2][mob];
- // Penalty if the piece is far from the king
- score -= KingProtector[Pt - 2] * distance(s, pos.square<KING>(Us));
-
if (Pt == BISHOP || Pt == KNIGHT)
{
// Bonus if piece is on an outpost square or can reach one
else if (bb &= b & ~pos.pieces(Us))
score += Outpost[Pt == BISHOP][bool(attackedBy[Us][PAWN] & bb)];
- // Bonus when behind a pawn
- if ( relative_rank(Us, s) < RANK_5
- && (pos.pieces(PAWN) & (s + pawn_push(Us))))
+ // Knight and Bishop bonus for being right behind a pawn
+ if (shift<Down>(pos.pieces(PAWN)) & s)
score += MinorBehindPawn;
+ // Penalty if the piece is far from the king
+ score -= KingProtector * distance(s, pos.square<KING>(Us));
+
if (Pt == BISHOP)
{
// Penalty according to number of pawns on the same color square as the
: AllSquares ^ Rank1BB ^ Rank2BB ^ Rank3BB);
const Square ksq = pos.square<KING>(Us);
- Bitboard weak, b, b1, b2, safe, unsafeChecks, pinned;
+ Bitboard weak, b, b1, b2, safe, unsafeChecks;
// King shelter and enemy pawns storm
Score score = pe->king_safety<Us>(pos, ksq);
// Unsafe or occupied checking squares will also be considered, as long as
// the square is in the attacker's mobility area.
unsafeChecks &= mobilityArea[Them];
- pinned = pos.blockers_for_king(Us) & pos.pieces(Us);
kingDanger += kingAttackersCount[Them] * kingAttackersWeight[Them]
- + 102 * kingAttacksCount[Them]
- + 191 * popcount(kingRing[Us] & weak)
- + 143 * popcount(pinned | unsafeChecks)
- - 848 * !pos.count<QUEEN>(Them)
- - 9 * mg_value(score) / 8
- + 40;
+ + 69 * kingAttacksCount[Them]
+ + 185 * popcount(kingRing[Us] & weak)
+ + 129 * popcount(pos.blockers_for_king(Us) | unsafeChecks)
+ - 873 * !pos.count<QUEEN>(Them)
+ - 6 * mg_value(score) / 8
+ - 2 ;
// Transform the kingDanger units into a Score, and subtract it from the evaluation
if (kingDanger > 0)
score += ThreatByRank * (int)relative_rank(Them, s);
}
- b = (pos.pieces(Them, QUEEN) | weak) & attackedBy[Us][ROOK];
+ b = weak & attackedBy[Us][ROOK];
while (b)
{
Square s = pop_lsb(&b);
score += ThreatByRank * (int)relative_rank(Them, s);
}
- b = weak & attackedBy[Us][KING];
- if (b)
- score += ThreatByKing[more_than_one(b)];
+ // Bonus for king attacks on pawns or pieces which are not pawn-defended
+ if (weak & attackedBy[Us][KING])
+ score += ThreatByKing;
score += Hanging * popcount(weak & ~attackedBy[Them][ALL_PIECES]);
- // Bonus for overload (non-pawn enemies attacked and defended exactly once)
- b = nonPawnEnemies
- & attackedBy[Us][ALL_PIECES] & ~attackedBy2[Us]
- & attackedBy[Them][ALL_PIECES] & ~attackedBy2[Them];
+ b = weak & nonPawnEnemies & attackedBy[Them][ALL_PIECES];
score += Overload * popcount(b);
}
score += SliderOnQueen * popcount(b & safeThreats & attackedBy2[Us]);
}
- // 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);
assert(!(pos.pieces(Them, PAWN) & forward_file_bb(Us, s + Up)));
- bb = forward_file_bb(Us, s) & (attackedBy[Them][ALL_PIECES] | pos.pieces(Them));
+ bb = forward_file_bb(Us, s) & pos.pieces(Them);
score -= HinderPassedPawn * popcount(bb);
int r = relative_rank(Us, s);
&& (pos.pieces(PAWN) & KingSide);
// Compute the initiative bonus for the attacking side
- int complexity = 8 * outflanking
- + 8 * pe->pawn_asymmetry()
+ int complexity = 8 * pe->pawn_asymmetry()
+ 12 * pos.count<PAWN>()
+ + 12 * outflanking
+ 16 * pawnsOnBothFlanks
+ 48 * !pos.non_pawn_material()
-136 ;
// If scale is not already specific, scale down the endgame via general heuristics
if (sf == SCALE_FACTOR_NORMAL)
{
- if (pos.opposite_bishops())
- {
- // Endgame with opposite-colored bishops and no other pieces is almost a draw
- if ( pos.non_pawn_material(WHITE) == BishopValueMg
- && pos.non_pawn_material(BLACK) == BishopValueMg)
- sf = 31;
-
- // Endgame with opposite-colored bishops, but also other pieces. Still
- // a bit drawish, but not as drawish as with only the two bishops.
- else
- sf = 46;
- }
+ if ( pos.opposite_bishops()
+ && pos.non_pawn_material(WHITE) == BishopValueMg
+ && pos.non_pawn_material(BLACK) == BishopValueMg)
+ sf = 31;
else
- sf = std::min(40 + 7 * pos.count<PAWN>(strongSide), sf);
+ sf = std::min(40 + (pos.opposite_bishops() ? 2 : 7) * pos.count<PAWN>(strongSide), sf);
}
return ScaleFactor(sf);