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) 2015-2017 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+ Copyright (C) 2015-2018 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
// Doubled pawn penalty
const Score Doubled = S(18, 38);
- // Lever bonus by rank
- const Score Lever[RANK_NB] = {
- S( 0, 0), S( 0, 0), S(0, 0), S(0, 0),
- S(17, 16), S(33, 32), S(0, 0), S(0, 0)
- };
-
// Weakness of our pawn shelter in front of the king by [isKingFile][distance from edge][rank].
// RANK_1 = 0 is used for files where we have no pawns or our pawn is behind our king.
const Value ShelterWeakness[][int(FILE_NB) / 2][RANK_NB] = {
- { { V( 97), V(17), V( 9), V(44), V( 84), V( 87), V( 99) }, // Not On King file
- { V(106), V( 6), V(33), V(86), V( 87), V(104), V(112) },
- { V(101), V( 2), V(65), V(98), V( 58), V( 89), V(115) },
- { V( 73), V( 7), V(54), V(73), V( 84), V( 83), V(111) } },
- { { V(104), V(20), V( 6), V(27), V( 86), V( 93), V( 82) }, // On King file
- { V(123), V( 9), V(34), V(96), V(112), V( 88), V( 75) },
- { V(120), V(25), V(65), V(91), V( 66), V( 78), V(117) },
- { V( 81), V( 2), V(47), V(63), V( 94), V( 93), V(104) } }
+ { { V( 98), V(20), V(11), V(42), V( 83), V( 84), V(101) }, // Not On King file
+ { V(103), V( 8), V(33), V(86), V( 87), V(105), V(113) },
+ { V(100), V( 2), V(65), V(95), V( 59), V( 89), V(115) },
+ { V( 72), V( 6), V(52), V(74), V( 83), V( 84), V(112) } },
+ { { V(105), V(19), V( 3), V(27), V( 85), V( 93), V( 84) }, // On King file
+ { V(121), V( 7), V(33), V(95), V(112), V( 86), V( 72) },
+ { V(121), V(26), V(65), V(90), V( 65), V( 76), V(117) },
+ { V( 79), V( 0), V(45), V(65), V( 94), V( 92), V(105) } }
};
// Danger of enemy pawns moving toward our king by [type][distance from edge][rank].
template<Color Us>
Score evaluate(const Position& pos, Pawns::Entry* e) {
- const Color Them = (Us == WHITE ? BLACK : WHITE);
- const Square Up = (Us == WHITE ? NORTH : SOUTH);
- const Square Right = (Us == WHITE ? NORTH_EAST : SOUTH_WEST);
- const Square Left = (Us == WHITE ? NORTH_WEST : SOUTH_EAST);
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
+ const Direction Up = (Us == WHITE ? NORTH : SOUTH);
Bitboard b, neighbours, stoppers, doubled, supported, phalanx;
Bitboard lever, leverPush;
e->passedPawns[Us] = e->pawnAttacksSpan[Us] = e->weakUnopposed[Us] = 0;
e->semiopenFiles[Us] = 0xFF;
e->kingSquares[Us] = SQ_NONE;
- e->pawnAttacks[Us] = shift<Right>(ourPawns) | shift<Left>(ourPawns);
+ e->pawnAttacks[Us] = pawn_attacks_bb<Us>(ourPawns);
e->pawnsOnSquares[Us][BLACK] = popcount(ourPawns & DarkSquares);
e->pawnsOnSquares[Us][WHITE] = pos.count<PAWN>(Us) - e->pawnsOnSquares[Us][BLACK];
if (doubled && !supported)
score -= Doubled;
-
- if (lever)
- score += Lever[relative_rank(Us, s)];
}
return score;
return e;
e->key = key;
- e->score = evaluate<WHITE>(pos, e) - evaluate<BLACK>(pos, e);
- e->asymmetry = popcount(e->semiopenFiles[WHITE] ^ e->semiopenFiles[BLACK]);
+ e->scores[WHITE] = evaluate<WHITE>(pos, e);
+ e->scores[BLACK] = evaluate<BLACK>(pos, e);
e->openFiles = popcount(e->semiopenFiles[WHITE] & e->semiopenFiles[BLACK]);
+ e->asymmetry = popcount( (e->passedPawns[WHITE] | e->passedPawns[BLACK])
+ | (e->semiopenFiles[WHITE] ^ e->semiopenFiles[BLACK]));
+
return e;
}
template<Color Us>
Value Entry::shelter_storm(const Position& pos, Square ksq) {
- const Color Them = (Us == WHITE ? BLACK : WHITE);
+ constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
+ constexpr Bitboard ShelterMask =
+ Us == WHITE ? make_bitboard(SQ_A2, SQ_B3, SQ_C2, SQ_F2, SQ_G3, SQ_H2)
+ : make_bitboard(SQ_A7, SQ_B6, SQ_C7, SQ_F7, SQ_G6, SQ_H7);
+ constexpr Bitboard StormMask =
+ Us == WHITE ? make_bitboard(SQ_A3, SQ_C3, SQ_F3, SQ_H3)
+ : make_bitboard(SQ_A6, SQ_C6, SQ_F6, SQ_H6);
enum { BlockedByKing, Unopposed, BlockedByPawn, Unblocked };
- Bitboard b = pos.pieces(PAWN) & (forward_ranks_bb(Us, ksq) | rank_bb(ksq));
+ File center = std::max(FILE_B, std::min(FILE_G, file_of(ksq)));
+ Bitboard b = pos.pieces(PAWN)
+ & (forward_ranks_bb(Us, ksq) | rank_bb(ksq))
+ & (adjacent_files_bb(center) | file_bb(center));
Bitboard ourPawns = b & pos.pieces(Us);
Bitboard theirPawns = b & pos.pieces(Them);
Value safety = MaxSafetyBonus;
- File center = std::max(FILE_B, std::min(FILE_G, file_of(ksq)));
- for (File f = center - File(1); f <= center + File(1); ++f)
+ for (File f = File(center - 1); f <= File(center + 1); ++f)
{
b = ourPawns & file_bb(f);
Rank rkUs = b ? relative_rank(Us, backmost_sq(Us, b)) : RANK_1;
b = theirPawns & file_bb(f);
Rank rkThem = b ? relative_rank(Us, frontmost_sq(Them, b)) : RANK_1;
- int d = std::min(f, FILE_H - f);
+ int d = std::min(f, ~f);
safety -= ShelterWeakness[f == file_of(ksq)][d][rkUs]
+ StormDanger
[f == file_of(ksq) && rkThem == relative_rank(Us, ksq) + 1 ? BlockedByKing :
[d][rkThem];
}
+ if (popcount((ourPawns & ShelterMask) | (theirPawns & StormMask)) == 5)
+ safety += Value(300);
+
return safety;
}
projects / stockfish / blobdiff