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
// 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) },
// 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
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 BishopPawns = S( 3, 8);
+ constexpr Score CloseEnemies = S( 7, 0);
constexpr Score CorneredBishop = S( 50, 50);
- constexpr Score Hanging = S( 57, 32);
- constexpr Score KingProtector = S( 6, 6);
- constexpr Score KnightOnQueen = S( 21, 11);
- constexpr Score LongDiagonalBishop = S( 46, 0);
+ constexpr Score Hanging = S( 62, 34);
+ constexpr Score KingProtector = S( 6, 7);
+ constexpr Score KnightOnQueen = S( 20, 12);
+ constexpr Score LongDiagonalBishop = S( 44, 0);
constexpr Score MinorBehindPawn = S( 16, 0);
- constexpr Score Overload = S( 13, 6);
- constexpr Score PawnlessFlank = S( 19, 84);
- constexpr Score RookOnPawn = S( 10, 30);
- 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 Overload = S( 12, 6);
+ constexpr Score PawnlessFlank = S( 18, 94);
+ constexpr Score RestrictedPiece = S( 7, 6);
+ constexpr Score RookOnPawn = S( 10, 28);
+ constexpr Score SliderOnQueen = S( 49, 21);
+ constexpr Score ThreatByKing = S( 21, 84);
+ constexpr Score ThreatByPawnPush = S( 48, 42);
+ constexpr Score ThreatByRank = S( 14, 3);
+ constexpr Score ThreatBySafePawn = S(169, 99);
+ constexpr Score TrappedRook = S( 98, 5);
+ constexpr Score WeakQueen = S( 51, 10);
+ constexpr Score WeakUnopposedPawn = S( 14, 20);
#undef S
attackedBy[Us][ALL_PIECES] = attackedBy[Us][KING] | attackedBy[Us][PAWN];
attackedBy2[Us] = attackedBy[Us][KING] & attackedBy[Us][PAWN];
+ kingRing[Us] = kingAttackersCount[Them] = 0;
+
// Init our king safety tables only if we are going to use them
if (pos.non_pawn_material(Them) >= RookValueMg + KnightValueMg)
{
kingAttackersCount[Them] = popcount(kingRing[Us] & pe->pawn_attacks(Them));
kingAttacksCount[Them] = kingAttackersWeight[Them] = 0;
}
- else
- kingRing[Us] = kingAttackersCount[Them] = 0;
}
Bitboard kingFlank, weak, b, b1, b2, safe, unsafeChecks;
// King shelter and enemy pawns storm
- Score score = pe->king_safety<Us>(pos, ksq);
+ 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.
+ // which are attacked twice in that flank.
kingFlank = KingFlank[file_of(ksq)];
b1 = attackedBy[Them][ALL_PIECES] & kingFlank & Camp;
- b2 = b1 & attackedBy2[Them] & ~attackedBy[Us][PAWN];
+ b2 = b1 & attackedBy2[Them];
int tropism = popcount(b1) + popcount(b2);
+ 69 * kingAttacksCount[Them]
+ 185 * popcount(kingRing[Us] & weak)
+ 150 * popcount(pos.blockers_for_king(Us) | unsafeChecks)
- + 4 * tropism
+ + tropism * tropism / 4
- 873 * !pos.count<QUEEN>(Them)
- 6 * mg_value(score) / 8
+ + mg_value(mobility[Them] - mobility[Us])
- 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);
- }
}
// Penalty when our king is on a pawnless flank
constexpr Direction Up = (Us == WHITE ? NORTH : SOUTH);
constexpr Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB);
- Bitboard b, weak, defended, nonPawnEnemies, stronglyProtected, safe;
+ Bitboard b, weak, defended, nonPawnEnemies, stronglyProtected, safe, restricted;
Score score = SCORE_ZERO;
// Non-pawn enemies
score += Overload * popcount(b);
}
+ // Bonus for restricting their piece moves
+ restricted = attackedBy[Them][ALL_PIECES]
+ & ~attackedBy[Them][PAWN]
+ & ~attackedBy2[Them]
+ & attackedBy[Us][ALL_PIECES];
+ score += RestrictedPiece * popcount(restricted);
+
// 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)));
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
bonus += make_score(k * w, k * w);
}
- } // w != 0
+ } // rank > 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.
projects / stockfish / blobdiff