Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
- Copyright (C) 2015-2018 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+ Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
namespace {
- constexpr Bitboard QueenSide = FileABB | FileBBB | FileCBB | FileDBB;
- constexpr Bitboard CenterFiles = FileCBB | FileDBB | FileEBB | FileFBB;
- constexpr Bitboard KingSide = FileEBB | FileFBB | FileGBB | FileHBB;
- constexpr Bitboard Center = (FileDBB | FileEBB) & (Rank4BB | Rank5BB);
-
- constexpr Bitboard KingFlank[FILE_NB] = {
- QueenSide ^ FileDBB, QueenSide, QueenSide,
- CenterFiles, CenterFiles,
- KingSide, KingSide, KingSide ^ FileEBB
- };
-
// Threshold for lazy and space evaluation
constexpr Value LazyThreshold = Value(1500);
constexpr Value SpaceThreshold = Value(12222);
// Penalties for enemy's safe checks
constexpr int QueenSafeCheck = 780;
- constexpr int RookSafeCheck = 880;
- constexpr int BishopSafeCheck = 435;
+ constexpr int RookSafeCheck = 1080;
+ constexpr int BishopSafeCheck = 635;
constexpr int KnightSafeCheck = 790;
#define S(mg, eg) make_score(mg, eg)
// MobilityBonus[PieceType-2][attacked] contains bonuses for middle and end game,
// indexed by piece type and number of attacked squares in the mobility area.
constexpr Score MobilityBonus[][32] = {
- { S(-75,-76), S(-57,-54), S( -9,-28), S( -2,-10), S( 6, 5), S( 14, 12), // Knights
- S( 22, 26), S( 29, 29), S( 36, 29) },
+ { S(-62,-81), S(-53,-56), S(-12,-30), S( -4,-14), S( 3, 8), S( 13, 15), // Knights
+ S( 22, 23), S( 28, 27), S( 33, 33) },
{ S(-48,-59), S(-20,-23), S( 16, -3), S( 26, 13), S( 38, 24), S( 51, 42), // Bishops
S( 55, 54), S( 63, 57), S( 63, 65), S( 68, 73), S( 81, 78), S( 81, 86),
S( 91, 88), S( 98, 97) },
S(106,184), S(109,191), S(113,206), S(116,212) }
};
- // Outpost[knight/bishop][supported by pawn] contains bonuses for minor
- // pieces if they occupy or can reach an outpost square, bigger if that
- // square is supported by a pawn.
- constexpr Score Outpost[][2] = {
- { S(22, 6), S(36,12) }, // Knight
- { S( 9, 2), S(15, 5) } // Bishop
- };
-
// RookOnFile[semiopen/open] contains bonuses for each rook when there is
// no (friendly) pawn on the rook file.
- constexpr Score RookOnFile[] = { S(20, 7), S(45, 20) };
+ constexpr Score RookOnFile[] = { S(18, 7), S(44, 20) };
// ThreatByMinor/ByRook[attacked PieceType] contains bonuses according to
// which piece type attacks which one. Attacks on lesser pieces which are
// pawn-defended are not considered.
constexpr Score ThreatByMinor[PIECE_TYPE_NB] = {
- S(0, 0), S(0, 31), S(39, 42), S(57, 44), S(68, 112), S(47, 120)
+ S(0, 0), S(0, 31), S(39, 42), S(57, 44), S(68, 112), S(62, 120)
};
constexpr Score ThreatByRook[PIECE_TYPE_NB] = {
- S(0, 0), S(0, 24), S(38, 71), S(38, 61), S(0, 38), S(36, 38)
+ S(0, 0), S(0, 24), S(38, 71), S(38, 61), S(0, 38), S(51, 38)
};
// PassedRank[Rank] contains a bonus according to the rank of a passed pawn
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, 7, 11, 20 };
-
// Assorted bonuses and penalties
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, 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( 13, 6);
- constexpr Score PawnlessFlank = S( 19, 84);
- constexpr Score RookOnPawn = S( 8, 24);
- constexpr Score SliderOnQueen = S( 42, 21);
- constexpr Score ThreatByKing = S( 23, 76);
- constexpr Score ThreatByPawnPush = S( 45, 40);
- constexpr Score ThreatByRank = S( 16, 3);
- constexpr Score ThreatBySafePawn = S(173,102);
- constexpr Score TrappedRook = S( 92, 0);
- constexpr Score WeakQueen = S( 50, 10);
- constexpr Score WeakUnopposedPawn = S( 5, 29);
+ constexpr Score FlankAttacks = S( 8, 0);
+ constexpr Score Hanging = S( 69, 36);
+ constexpr Score KingProtector = S( 7, 8);
+ 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 PawnlessFlank = S( 17, 95);
+ constexpr Score RestrictedPiece = S( 7, 7);
+ constexpr Score RookOnPawn = S( 10, 32);
+ constexpr Score SliderOnQueen = S( 59, 18);
+ constexpr Score ThreatByKing = S( 24, 89);
+ constexpr Score ThreatByPawnPush = S( 48, 39);
+ constexpr Score ThreatByRank = S( 13, 0);
+ 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. It is set to 0 when king safety evaluation is skipped.
+ // and h6.
Bitboard kingRing[COLOR_NB];
// kingAttackersCount[color] is the number of pieces of the given color
constexpr Direction Down = (Us == WHITE ? SOUTH : NORTH);
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);
- // Squares occupied by those pawns, by our king or queen, or controlled by enemy pawns
- // are excluded from the mobility area.
+ // Squares occupied by those pawns, by our king or queen or controlled by
+ // enemy pawns are excluded from the mobility area.
mobilityArea[Us] = ~(b | pos.pieces(Us, KING, QUEEN) | pe->pawn_attacks(Them));
- // Initialise attackedBy bitboards for kings and pawns
- attackedBy[Us][KING] = pos.attacks_from<KING>(pos.square<KING>(Us));
+ // Initialize attackedBy[] for king and pawns
+ 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 only if we are going to use them
- if (pos.non_pawn_material(Them) >= RookValueMg + KnightValueMg)
- {
- kingRing[Us] = attackedBy[Us][KING];
- if (relative_rank(Us, pos.square<KING>(Us)) == RANK_1)
- kingRing[Us] |= shift<Up>(kingRing[Us]);
+ // Init our king safety tables
+ kingRing[Us] = attackedBy[Us][KING];
+ if (relative_rank(Us, ksq) == RANK_1)
+ kingRing[Us] |= shift<Up>(kingRing[Us]);
- if (file_of(pos.square<KING>(Us)) == FILE_H)
- kingRing[Us] |= shift<WEST>(kingRing[Us]);
+ if (file_of(ksq) == FILE_H)
+ kingRing[Us] |= shift<WEST>(kingRing[Us]);
- else if (file_of(pos.square<KING>(Us)) == FILE_A)
- kingRing[Us] |= shift<EAST>(kingRing[Us]);
+ else if (file_of(ksq) == FILE_A)
+ kingRing[Us] |= shift<EAST>(kingRing[Us]);
- kingAttackersCount[Them] = popcount(kingRing[Us] & pe->pawn_attacks(Them));
- kingAttacksCount[Them] = kingAttackersWeight[Them] = 0;
- }
- else
- kingRing[Us] = kingAttackersCount[Them] = 0;
+ kingAttackersCount[Them] = popcount(kingRing[Us] & pe->pawn_attacks(Them));
+ kingAttacksCount[Them] = kingAttackersWeight[Them] = 0;
+
+ // Remove from kingRing[] the squares defended by two pawns
+ kingRing[Us] &= ~dblAttackByPawn;
}
const Square* pl = pos.squares<Pt>(Us);
Bitboard b, bb;
- Square s;
Score score = SCORE_ZERO;
attackedBy[Us][Pt] = 0;
- while ((s = *pl++) != SQ_NONE)
+ for (Square s = *pl; s != SQ_NONE; s = *++pl)
{
// Find attacked squares, including x-ray attacks for bishops and rooks
b = Pt == BISHOP ? attacks_bb<BISHOP>(s, pos.pieces() ^ pos.pieces(QUEEN))
// Bonus if piece is on an outpost square or can reach one
bb = OutpostRanks & ~pe->pawn_attacks_span(Them);
if (bb & s)
- score += Outpost[Pt == BISHOP][bool(attackedBy[Us][PAWN] & s)] * 2;
+ score += Outpost * (Pt == KNIGHT ? 4 : 2)
+ * ((attackedBy[Us][PAWN] & s) ? 2 : 1);
else if (bb &= b & ~pos.pieces(Us))
- score += Outpost[Pt == BISHOP][bool(attackedBy[Us][PAWN] & bb)];
+ score += Outpost * (Pt == KNIGHT ? 2 : 1)
+ * ((attackedBy[Us][PAWN] & bb) ? 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
- if (more_than_one(Center & (attacks_bb<BISHOP>(s, pos.pieces(PAWN)) | s)))
+ if (more_than_one(attacks_bb<BISHOP>(s, pos.pieces(PAWN)) & Center))
score += LongDiagonalBishop;
}
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)
{
File kf = file_of(pos.square<KING>(Us));
if ((kf < FILE_E) == (file_of(s) < kf))
- score -= (TrappedRook - make_score(mob * 22, 0)) * (1 + !pos.can_castle(Us));
+ score -= TrappedRook * (1 + !pos.castling_rights(Us));
}
}
constexpr Bitboard Camp = (Us == WHITE ? AllSquares ^ Rank6BB ^ Rank7BB ^ Rank8BB
: AllSquares ^ Rank1BB ^ Rank2BB ^ Rank3BB);
+ Bitboard weak, b1, b2, safe, unsafeChecks = 0;
+ Bitboard rookChecks, queenChecks, bishopChecks, knightChecks;
+ int kingDanger = 0;
const Square ksq = pos.square<KING>(Us);
- Bitboard kingFlank, weak, b, b1, b2, safe, unsafeChecks;
- // King shelter and enemy pawns storm
- Score score = pe->king_safety<Us>(pos, ksq);
+ // Init the score with king shelter and enemy pawns storm
+ Score score = pe->king_safety<Us>(pos);
- // 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];
+ // Attacked squares defended at most once by our queen or king
+ weak = attackedBy[Them][ALL_PIECES]
+ & ~attackedBy2[Us]
+ & (~attackedBy[Us][ALL_PIECES] | attackedBy[Us][KING] | attackedBy[Us][QUEEN]);
- int tropism = popcount(b1) + popcount(b2);
+ // Analyse the safe enemy's checks which are possible on next move
+ safe = ~pos.pieces(Them);
+ safe &= ~attackedBy[Us][ALL_PIECES] | (weak & attackedBy2[Them]);
- // Main king safety evaluation
- if (kingAttackersCount[Them] > 1 - pos.count<QUEEN>(Them))
- {
- int kingDanger = 0;
- unsafeChecks = 0;
+ b1 = attacks_bb<ROOK >(ksq, pos.pieces() ^ pos.pieces(Us, QUEEN));
+ b2 = attacks_bb<BISHOP>(ksq, pos.pieces() ^ pos.pieces(Us, QUEEN));
- // Attacked squares defended at most once by our queen or king
- weak = attackedBy[Them][ALL_PIECES]
- & ~attackedBy2[Us]
- & (~attackedBy[Us][ALL_PIECES] | attackedBy[Us][KING] | attackedBy[Us][QUEEN]);
+ // Enemy rooks checks
+ rookChecks = b1 & safe & attackedBy[Them][ROOK];
- // Analyse the safe enemy's checks which are possible on next move
- safe = ~pos.pieces(Them);
- safe &= ~attackedBy[Us][ALL_PIECES] | (weak & attackedBy2[Them]);
-
- b1 = attacks_bb<ROOK >(ksq, pos.pieces() ^ pos.pieces(Us, QUEEN));
- b2 = attacks_bb<BISHOP>(ksq, pos.pieces() ^ pos.pieces(Us, QUEEN));
-
- // Enemy queen safe checks
- if ((b1 | b2) & attackedBy[Them][QUEEN] & safe & ~attackedBy[Us][QUEEN])
- kingDanger += QueenSafeCheck;
+ if (rookChecks)
+ kingDanger += RookSafeCheck;
+ else
+ unsafeChecks |= b1 & attackedBy[Them][ROOK];
+
+ // Enemy queen safe checks: we count them only if they are from squares from
+ // which we can't give a rook check, because rook checks are more valuable.
+ queenChecks = (b1 | b2)
+ & attackedBy[Them][QUEEN]
+ & safe
+ & ~attackedBy[Us][QUEEN]
+ & ~rookChecks;
+
+ if (queenChecks)
+ kingDanger += QueenSafeCheck;
+
+ // Enemy bishops checks: we count them only if they are from squares from
+ // which we can't give a queen check, because queen checks are more valuable.
+ bishopChecks = b2
+ & attackedBy[Them][BISHOP]
+ & safe
+ & ~queenChecks;
+
+ if (bishopChecks)
+ kingDanger += BishopSafeCheck;
+ else
+ unsafeChecks |= b2 & attackedBy[Them][BISHOP];
- b1 &= attackedBy[Them][ROOK];
- b2 &= attackedBy[Them][BISHOP];
+ // Enemy knights checks
+ knightChecks = pos.attacks_from<KNIGHT>(ksq) & attackedBy[Them][KNIGHT];
- // Enemy rooks checks
- if (b1 & safe)
- kingDanger += RookSafeCheck;
- else
- unsafeChecks |= b1;
+ if (knightChecks & safe)
+ kingDanger += KnightSafeCheck;
+ else
+ unsafeChecks |= knightChecks;
- // Enemy bishops checks
- if (b2 & safe)
- kingDanger += BishopSafeCheck;
- else
- unsafeChecks |= b2;
+ // Unsafe or occupied checking squares will also be considered, as long as
+ // the square is in the attacker's mobility area.
+ unsafeChecks &= mobilityArea[Them];
- // Enemy knights checks
- b = pos.attacks_from<KNIGHT>(ksq) & attackedBy[Them][KNIGHT];
- if (b & safe)
- kingDanger += KnightSafeCheck;
- else
- unsafeChecks |= b;
-
- // Unsafe or occupied checking squares will also be considered, as long as
- // the square is in the attacker's mobility area.
- unsafeChecks &= mobilityArea[Them];
-
- kingDanger += kingAttackersCount[Them] * kingAttackersWeight[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
- - 30;
-
- // Transform the kingDanger units into a Score, and subtract it from the evaluation
- if (kingDanger > 0)
- {
- int mobilityDanger = mg_value(mobility[Them] - mobility[Us]);
- kingDanger = std::max(0, kingDanger + mobilityDanger);
- score -= make_score(kingDanger * kingDanger / 4096, kingDanger / 16);
- }
- }
+ // Find the squares that opponent attacks in our king flank, and the squares
+ // which are attacked twice in that flank.
+ b1 = attackedBy[Them][ALL_PIECES] & KingFlank[file_of(ksq)] & Camp;
+ b2 = b1 & attackedBy2[Them];
+
+ int kingFlankAttacks = popcount(b1) + popcount(b2);
+
+ kingDanger += kingAttackersCount[Them] * kingAttackersWeight[Them]
+ + 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
+ - 7;
+
+ // Transform the kingDanger units into a Score, and subtract it from the evaluation
+ if (kingDanger > 100)
+ score -= make_score(kingDanger * kingDanger / 4096, kingDanger / 16);
// Penalty when our king is on a pawnless flank
- if (!(pos.pieces(PAWN) & kingFlank))
+ if (!(pos.pieces(PAWN) & KingFlank[file_of(ksq)]))
score -= PawnlessFlank;
- // King tropism bonus, to anticipate slow motion attacks on our king
- score -= CloseEnemies * tropism;
+ // Penalty if king flank is under attack, potentially moving toward the king
+ score -= FlankAttacks * kingFlankAttacks;
if (T)
Trace::add(KING, Us, score);
Score score = SCORE_ZERO;
// Non-pawn enemies
- nonPawnEnemies = pos.pieces(Them) ^ pos.pieces(Them, PAWN);
+ nonPawnEnemies = pos.pieces(Them) & ~pos.pieces(PAWN);
// Squares strongly protected by the enemy, either because they defend the
// square with a pawn, or because they defend the square twice and we don't.
score += ThreatByMinor[type_of(pos.piece_on(s))];
if (type_of(pos.piece_on(s)) != PAWN)
score += ThreatByRank * (int)relative_rank(Them, s);
-
- else if (pos.blockers_for_king(Them) & s)
- score += ThreatByRank * (int)relative_rank(Them, s) / 2;
}
b = weak & attackedBy[Us][ROOK];
score += ThreatByRook[type_of(pos.piece_on(s))];
if (type_of(pos.piece_on(s)) != PAWN)
score += ThreatByRank * (int)relative_rank(Them, s);
-
- else if (pos.blockers_for_king(Them) & s)
- score += ThreatByRank * (int)relative_rank(Them, s) / 2;
}
if (weak & attackedBy[Us][KING])
score += ThreatByKing;
- score += Hanging * popcount(weak & ~attackedBy[Them][ALL_PIECES]);
-
- b = weak & nonPawnEnemies & attackedBy[Them][ALL_PIECES];
- score += Overload * popcount(b);
+ b = ~attackedBy[Them][ALL_PIECES]
+ | (nonPawnEnemies & attackedBy2[Us]);
+ score += Hanging * popcount(weak & b);
}
+ // Bonus for restricting their piece moves
+ b = attackedBy[Them][ALL_PIECES]
+ & ~stronglyProtected
+ & attackedBy[Us][ALL_PIECES];
+
+ score += RestrictedPiece * popcount(b);
+
// Bonus for enemy unopposed weak pawns
if (pos.pieces(Us, ROOK, QUEEN))
score += WeakUnopposedPawn * pe->weak_unopposed(Them);
assert(!(pos.pieces(Them, PAWN) & forward_file_bb(Us, s + Up)));
- if (forward_file_bb(Us, s) & pos.pieces(Them))
- score -= HinderPassedPawn;
-
int r = relative_rank(Us, s);
- int w = PassedDanger[r];
Score bonus = PassedRank[r];
- if (w)
+ if (r > RANK_3)
{
+ int w = (r-2) * (r-2) + 2;
Square blockSq = s + Up;
// Adjust bonus based on the king's proximity
// in the pawn's path attacked or occupied by the enemy.
defendedSquares = unsafeSquares = squaresToQueen = forward_file_bb(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];
bonus += make_score(k * w, k * w);
}
- else if (pos.pieces(Us) & blockSq)
- bonus += make_score(w + r * 2, w + r * 2);
- } // w != 0
+ } // 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.
if (pos.non_pawn_material() < SpaceThreshold)
return SCORE_ZERO;
- constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
+ constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
+ constexpr Direction Down = (Us == WHITE ? SOUTH : NORTH);
constexpr Bitboard SpaceMask =
Us == WHITE ? CenterFiles & (Rank2BB | Rank3BB | Rank4BB)
: CenterFiles & (Rank7BB | Rank6BB | Rank5BB);
// Find all squares which are at most three squares behind some friendly pawn
Bitboard behind = pos.pieces(Us, PAWN);
- behind |= (Us == WHITE ? behind >> 8 : behind << 8);
- behind |= (Us == WHITE ? behind >> 16 : behind << 16);
+ behind |= shift<Down>(behind);
+ behind |= shift<Down+Down>(behind);
int bonus = popcount(safe) + popcount(behind & safe);
- int weight = pos.count<ALL_PIECES>(Us) - 2 * pe->open_files();
-
+ int weight = pos.count<ALL_PIECES>(Us) - 1;
Score score = make_score(bonus * weight * weight / 16, 0);
if (T)
&& (pos.pieces(PAWN) & KingSide);
// Compute the initiative bonus for the attacking side
- int complexity = 8 * pe->pawn_asymmetry()
- + 1
2 * pos.count<PAWN>()
- + 12 * outflanking
- + 16 * pawnsOnBothFlanks
- + 48 * !pos.non_pawn_material()
- -136 ;
+ int complexity = 9 * pe->passed_count()
+ + 1
1 * pos.count<PAWN>()
+ + 9 * outflanking
+ + 18 * pawnsOnBothFlanks
+ + 49 * !pos.non_pawn_material()
+ -103 ;
// Now apply the bonus: note that we find the attacking side by extracting
// the sign of the endgame value, and that we carefully cap the bonus so
if (sf == SCALE_FACTOR_NORMAL)
{
if ( pos.opposite_bishops()
- && pos.non_pawn_material(WHITE) == BishopValueMg
- && pos.non_pawn_material(BLACK) == BishopValueMg)
- sf = 31;
+ && 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);
+
}
return ScaleFactor(sf);
v = mg_value(score) * int(me->game_phase())
+ eg_value(score) * int(PHASE_MIDGAME - me->game_phase()) * sf / SCALE_FACTOR_NORMAL;
- v /= int(PHASE_MIDGAME);
+ v /= PHASE_MIDGAME;
// In case of tracing add all remaining individual evaluation terms
if (T)
<< " ------------+-------------+-------------+------------\n"
<< " Material | " << Term(MATERIAL)
<< " Imbalance | " << Term(IMBALANCE)
- << " Initiative | " << Term(INITIATIVE)
<< " Pawns | " << Term(PAWN)
<< " Knights | " << Term(KNIGHT)
<< " Bishops | " << Term(BISHOP)
<< " Threats | " << Term(THREAT)
<< " Passed | " << Term(PASSED)
<< " Space | " << Term(SPACE)
+ << " Initiative | " << Term(INITIATIVE)
<< " ------------+-------------+-------------+------------\n"
<< " Total | " << Term(TOTAL);
projects / stockfish / blobdiff