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
#define S(mg, eg) make_score(mg, eg)
// Pawn penalties
- constexpr Score Isolated = S( 4, 20);
- constexpr Score Backward = S(21, 22);
- constexpr Score Doubled = S(12, 54);
+ constexpr Score Backward = S( 9, 24);
+ constexpr Score Doubled = S(11, 56);
+ constexpr Score Isolated = S( 5, 15);
// Connected pawn bonus by opposed, phalanx, #support and rank
Score Connected[2][2][3][RANK_NB];
// Strength of pawn shelter for our king by [distance from edge][rank].
// RANK_1 = 0 is used for files where we have no pawn, or pawn is behind our king.
constexpr Value ShelterStrength[int(FILE_NB) / 2][RANK_NB] = {
- { V( 16), V(82), V( 83), V( 47), V( 19), V( 44), V( 4) },
- { V(-51), V(56), V( 33), V(-58), V(-57), V(-50), V(-39) },
- { V(-20), V(71), V( 16), V(-10), V( 13), V( 19), V(-30) },
- { V(-29), V(12), V(-21), V(-40), V(-15), V(-77), V(-91) }
+ { V( -6), V( 81), V( 93), V( 58), V( 39), V( 18), V( 25) },
+ { V(-43), V( 61), V( 35), V(-49), V(-29), V(-11), V( -63) },
+ { V(-10), V( 75), V( 23), V( -2), V( 32), V( 3), V( -45) },
+ { V(-39), V(-13), V(-29), V(-52), V(-48), V(-67), V(-166) }
};
// Danger of enemy pawns moving toward our king by [distance from edge][rank].
// RANK_1 = 0 is used for files where the enemy has no pawn, or their pawn
// is behind our king.
constexpr Value UnblockedStorm[int(FILE_NB) / 2][RANK_NB] = {
- { V(54), V( 48), V( 99), V(91), V(42), V( 32), V( 31) },
- { V(34), V( 27), V(105), V(38), V(32), V(-19), V( 3) },
- { V(-4), V( 28), V( 87), V(18), V(-3), V(-14), V(-11) },
- { V(-5), V( 22), V( 75), V(14), V( 2), V( -5), V(-19) }
+ { V( 89), V(107), V(123), V(93), V(57), V( 45), V( 51) },
+ { V( 44), V(-18), V(123), V(46), V(39), V( -7), V( 23) },
+ { V( 4), V( 52), V(162), V(37), V( 7), V(-14), V( -2) },
+ { V(-10), V(-14), V( 90), V(15), V( 2), V( -7), V(-16) }
};
- // Danger of blocked enemy pawns storming our king, by rank
- constexpr Value BlockedStorm[RANK_NB] =
- { V(0), V(0), V( 81), V(-9), V(-5), V(-1), V(26) };
-
#undef S
#undef V
// which could become passed after one or two pawn pushes when are
// not attacked more times than defended.
if ( !(stoppers ^ lever ^ leverPush)
- && !(ourPawns & forward_file_bb(Us, s))
&& popcount(supported) >= popcount(lever) - 1
&& popcount(phalanx) >= popcount(leverPush))
e->passedPawns[Us] |= s;
constexpr Direction Down = (Us == WHITE ? SOUTH : NORTH);
constexpr Bitboard BlockRanks = (Us == WHITE ? Rank1BB | Rank2BB : Rank8BB | Rank7BB);
- Bitboard b = pos.pieces(PAWN) & (forward_ranks_bb(Us, ksq) | rank_bb(ksq));
+ Bitboard b = pos.pieces(PAWN) & ~forward_ranks_bb(Them, ksq);
Bitboard ourPawns = b & pos.pieces(Us);
Bitboard theirPawns = b & pos.pieces(Them);
- Value safety = (ourPawns & file_bb(ksq)) ? Value(5) : Value(-5);
-
- if (shift<Down>(theirPawns) & (FileABB | FileHBB) & BlockRanks & ksq)
- safety += Value(374);
+ Value safety = (shift<Down>(theirPawns) & (FileABB | FileHBB) & BlockRanks & ksq) ?
+ Value(374) : Value(5);
File center = std::max(FILE_B, std::min(FILE_G, file_of(ksq)));
for (File f = File(center - 1); f <= File(center + 1); ++f)
int d = std::min(f, ~f);
safety += ShelterStrength[d][ourRank];
- safety -= (ourRank && (ourRank == theirRank - 1)) ? BlockedStorm[theirRank]
+ safety -= (ourRank && (ourRank == theirRank - 1)) ? 66 * (theirRank == RANK_3)
: UnblockedStorm[d][theirRank];
}
/// when king square changes, which is about 20% of total king_safety() calls.
template<Color Us>
-Score Entry::do_king_safety(const Position& pos, Square ksq) {
+Score Entry::do_king_safety(const Position& pos) {
+ Square ksq = pos.square<KING>(Us);
kingSquares[Us] = ksq;
castlingRights[Us] = pos.can_castle(Us);
int minKingPawnDistance = 0;
Bitboard pawns = pos.pieces(Us, PAWN);
if (pawns)
- while (!(DistanceRingBB[ksq][minKingPawnDistance++] & pawns)) {}
+ while (!(DistanceRingBB[ksq][++minKingPawnDistance] & pawns)) {}
Value bonus = evaluate_shelter<Us>(pos, ksq);
// If we can castle use the bonus after the castling if it is bigger
- if (pos.can_castle(MakeCastling<Us, KING_SIDE>::right))
+ if (pos.can_castle(Us | KING_SIDE))
bonus = std::max(bonus, evaluate_shelter<Us>(pos, relative_square(Us, SQ_G1)));
- if (pos.can_castle(MakeCastling<Us, QUEEN_SIDE>::right))
+ if (pos.can_castle(Us | QUEEN_SIDE))
bonus = std::max(bonus, evaluate_shelter<Us>(pos, relative_square(Us, SQ_C1)));
return make_score(bonus, -16 * minKingPawnDistance);
}
// Explicit template instantiation
-template Score Entry::do_king_safety<WHITE>(const Position& pos, Square ksq);
-template Score Entry::do_king_safety<BLACK>(const Position& pos, Square ksq);
+template Score Entry::do_king_safety<WHITE>(const Position& pos);
+template Score Entry::do_king_safety<BLACK>(const Position& pos);
} // namespace Pawns