namespace {
// Threshold for lazy and space evaluation
- constexpr Value LazyThreshold = Value(1500);
+ constexpr Value LazyThreshold = Value(1400);
constexpr Value SpaceThreshold = Value(12222);
// KingAttackWeights[PieceType] contains king attack weights by piece type
};
// Assorted bonuses and penalties
+ constexpr Score AttacksOnSpaceArea = S( 4, 0);
constexpr Score BishopPawns = S( 3, 7);
constexpr Score CorneredBishop = S( 50, 50);
constexpr Score FlankAttacks = S( 8, 0);
constexpr Score KnightOnQueen = S( 16, 12);
constexpr Score LongDiagonalBishop = S( 45, 0);
constexpr Score MinorBehindPawn = S( 18, 3);
- constexpr Score Outpost = S( 9, 3);
+ constexpr Score Outpost = S( 18, 6);
constexpr Score PawnlessFlank = S( 17, 95);
constexpr Score RestrictedPiece = S( 7, 7);
constexpr Score RookOnPawn = S( 10, 32);
constexpr Score ThreatBySafePawn = S(173, 94);
constexpr Score TrappedRook = S( 47, 4);
constexpr Score WeakQueen = S( 49, 15);
- constexpr Score WeakUnopposedPawn = S( 12, 23);
#undef S
// 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,
- // possibly via x-ray or by one pawn and one piece. Diagonal x-ray through
- // pawn or squares attacked by 2 pawns are not explicitly added.
+ // attackedBy2[color] are the squares attacked by at least 2 units of a given
+ // color, including x-rays. But diagonal x-rays through pawns are not computed.
Bitboard attackedBy2[COLOR_NB];
- // kingRing[color] are the squares adjacent to the king, plus (only for a
- // king on its first rank) the squares two ranks in front. For instance,
- // if black's king is on g8, kingRing[BLACK] is f8, h8, f7, g7, h7, f6, g6
- // and h6.
+ // kingRing[color] are the squares adjacent to the king plus some other
+ // very near squares, depending on king position.
Bitboard kingRing[COLOR_NB];
// kingAttackersCount[color] is the number of pieces of the given color
constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
constexpr Direction Up = (Us == WHITE ? NORTH : SOUTH);
constexpr Direction Down = (Us == WHITE ? SOUTH : NORTH);
- constexpr Bitboard LowRanks = (Us == WHITE ? Rank2BB | Rank3BB: Rank7BB | Rank6BB);
+ constexpr Bitboard LowRanks = (Us == WHITE ? Rank2BB | Rank3BB : Rank7BB | Rank6BB);
const Square ksq = pos.square<KING>(Us);
+ Bitboard dblAttackByPawn = pawn_double_attacks_bb<Us>(pos.pieces(Us, PAWN));
+
// Find our pawns that are blocked or on the first two ranks
Bitboard b = pos.pieces(Us, PAWN) & (shift<Down>(pos.pieces()) | LowRanks);
attackedBy[Us][KING] = pos.attacks_from<KING>(ksq);
attackedBy[Us][PAWN] = pe->pawn_attacks(Us);
attackedBy[Us][ALL_PIECES] = attackedBy[Us][KING] | attackedBy[Us][PAWN];
- attackedBy2[Us] = attackedBy[Us][KING] & attackedBy[Us][PAWN];
+ attackedBy2[Us] = dblAttackByPawn | (attackedBy[Us][KING] & attackedBy[Us][PAWN]);
// Init our king safety tables
kingRing[Us] = attackedBy[Us][KING];
kingAttacksCount[Them] = kingAttackersWeight[Them] = 0;
// Remove from kingRing[] the squares defended by two pawns
- kingRing[Us] &= ~pawn_double_attacks_bb<Us>(pos.pieces(Us, PAWN));
+ kingRing[Us] &= ~dblAttackByPawn;
}
if (Pt == BISHOP || Pt == KNIGHT)
{
// Bonus if piece is on an outpost square or can reach one
- bb = OutpostRanks & ~pe->pawn_attacks_span(Them);
+ bb = OutpostRanks & attackedBy[Us][PAWN] & ~pe->pawn_attacks_span(Them);
if (bb & s)
- score += Outpost * (Pt == KNIGHT ? 4 : 2)
- * (1 + bool(attackedBy[Us][PAWN] & s));
+ score += Outpost * (Pt == KNIGHT ? 4 : 2);
- else if (bb &= b & ~pos.pieces(Us))
- score += Outpost * (Pt == KNIGHT ? 2 : 1)
- * (1 + bool(attackedBy[Us][PAWN] & bb));
+ else if (bb & b & ~pos.pieces(Us))
+ score += Outpost * (Pt == KNIGHT ? 2 : 1);
// Knight and Bishop bonus for being right behind a pawn
if (shift<Down>(pos.pieces(PAWN)) & s)
// bishop, bigger when the center files are blocked with pawns.
Bitboard blocked = pos.pieces(Us, PAWN) & shift<Down>(pos.pieces());
- score -= BishopPawns * pe->pawns_on_same_color_squares(Us, s)
+ score -= BishopPawns * pos.pawns_on_same_color_squares(Us, s)
* (1 + popcount(blocked & CenterFiles));
// Bonus for bishop on a long diagonal which can "see" both center squares
score += RookOnPawn * popcount(pos.pieces(Them, PAWN) & PseudoAttacks[ROOK][s]);
// Bonus for rook on an open or semi-open file
- if (pe->semiopen_file(Us, file_of(s)))
- score += RookOnFile[bool(pe->semiopen_file(Them, file_of(s)))];
+ if (pos.is_on_semiopen_file(Us, s))
+ score += RookOnFile[bool(pos.is_on_semiopen_file(Them, s))];
// Penalty when trapped by the king, even more if the king cannot castle
else if (mob <= 3)
+ 69 * kingAttacksCount[Them]
+ 185 * popcount(kingRing[Us] & weak)
- 100 * bool(attackedBy[Us][KNIGHT] & attackedBy[Us][KING])
+ - 35 * bool(attackedBy[Us][BISHOP] & attackedBy[Us][KING])
+ 150 * popcount(pos.blockers_for_king(Us) | unsafeChecks)
- 873 * !pos.count<QUEEN>(Them)
- 6 * mg_value(score) / 8
+ mg_value(mobility[Them] - mobility[Us])
+ 5 * kingFlankAttacks * kingFlankAttacks / 16
- - 25;
+ - 7;
// Transform the kingDanger units into a Score, and subtract it from the evaluation
- if (kingDanger > 0)
+ if (kingDanger > 100)
score -= make_score(kingDanger * kingDanger / 4096, kingDanger / 16);
// Penalty when our king is on a pawnless flank
score += RestrictedPiece * popcount(b);
- // Bonus for enemy unopposed weak pawns
- if (pos.pieces(Us, ROOK, QUEEN))
- score += WeakUnopposedPawn * pe->weak_unopposed(Them);
-
// Find squares where our pawns can push on the next move
b = shift<Up>(pos.pieces(Us, PAWN)) & ~pos.pieces();
b |= shift<Up>(b & TRank3BB) & ~pos.pieces();
b &= ~attackedBy[Them][PAWN] & safe;
// Bonus for safe pawn threats on the next move
- b = pawn_attacks_bb<Us>(b) & pos.pieces(Them);
+ b = pawn_attacks_bb<Us>(b) & nonPawnEnemies;
score += ThreatByPawnPush * popcount(b);
// Our safe or protected pawns
// If the pawn is free to advance, then increase the bonus
if (pos.empty(blockSq))
{
- // If there is a rook or queen attacking/defending the pawn from behind,
- // consider all the squaresToQueen. Otherwise consider only the squares
- // in the pawn's path attacked or occupied by the enemy.
- defendedSquares = unsafeSquares = squaresToQueen = forward_file_bb(Us, s);
+ defendedSquares = squaresToQueen = forward_file_bb(Us, s);
+ unsafeSquares = passed_pawn_span(Us, s);
- bb = forward_file_bb(Them, s) & pos.pieces(ROOK, QUEEN) & pos.attacks_from<ROOK>(s);
+ bb = forward_file_bb(Them, s) & pos.pieces(ROOK, QUEEN);
if (!(pos.pieces(Us) & bb))
defendedSquares &= attackedBy[Us][ALL_PIECES];
if (!(pos.pieces(Them) & bb))
unsafeSquares &= attackedBy[Them][ALL_PIECES] | pos.pieces(Them);
- // If there aren't any enemy attacks, assign a big bonus. Otherwise
- // assign a smaller bonus if the block square isn't attacked.
- int k = !unsafeSquares ? 20 : !(unsafeSquares & blockSq) ? 9 : 0;
+ // If there are no enemy attacks on passed pawn span, assign a big bonus.
+ // Otherwise assign a smaller bonus if the path to queen is not attacked
+ // and even smaller bonus if it is attacked but block square is not.
+ int k = !unsafeSquares ? 35 :
+ !(unsafeSquares & squaresToQueen) ? 20 :
+ !(unsafeSquares & blockSq) ? 9 :
+ 0 ;
- // If the path to the queen is fully defended, assign a big bonus.
- // Otherwise assign a smaller bonus if the block square is defended.
- if (defendedSquares == squaresToQueen)
- k += 6;
-
- else if (defendedSquares & blockSq)
- k += 4;
+ // Assign a larger bonus if the block square is defended.
+ if (defendedSquares & blockSq)
+ k += 5;
bonus += make_score(k * w, k * w);
}
- } // rank > RANK_3
+ } // r > RANK_3
// Scale down bonus for candidate passers which need more than one
// pawn push to become passed, or have a pawn in front of them.
// Find all squares which are at most three squares behind some friendly pawn
Bitboard behind = pos.pieces(Us, PAWN);
behind |= shift<Down>(behind);
- behind |= shift<Down>(shift<Down>(behind));
+ behind |= shift<Down+Down>(behind);
int bonus = popcount(safe) + popcount(behind & safe);
- int weight = pos.count<ALL_PIECES>(Us)
- - 2 * popcount(pe->semiopenFiles[WHITE] & pe->semiopenFiles[BLACK]);
-
+ int weight = pos.count<ALL_PIECES>(Us) - 1;
Score score = make_score(bonus * weight * weight / 16, 0);
+ score -= AttacksOnSpaceArea * popcount(attackedBy[Them][ALL_PIECES] & behind & safe);
+
if (T)
Trace::add(SPACE, Us, score);
if (sf == SCALE_FACTOR_NORMAL)
{
if ( pos.opposite_bishops()
- && pos.non_pawn_material(WHITE) == BishopValueMg
- && pos.non_pawn_material(BLACK) == BishopValueMg)
+ && pos.non_pawn_material() == 2 * BishopValueMg)
sf = 16 + 4 * pe->passed_count();
else
sf = std::min(40 + (pos.opposite_bishops() ? 2 : 7) * pos.count<PAWN>(strongSide), sf);
// Early exit if score is high
Value v = (mg_value(score) + eg_value(score)) / 2;
- if (abs(v) > LazyThreshold)
+ if (abs(v) > LazyThreshold + pos.non_pawn_material() / 64)
return pos.side_to_move() == WHITE ? v : -v;
// Main evaluation begins here
projects / stockfish / blobdiff