/*
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) 2015-2020 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+ Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
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 Backward = S( 9, 24);
- constexpr Score Doubled = S(11, 56);
- constexpr Score Isolated = S( 5, 15);
- constexpr Score WeakLever = S( 0, 56);
- constexpr Score WeakUnopposed = S(13, 27);
+ constexpr Score Backward = S( 6, 23);
+ constexpr Score Doubled = S(13, 53);
+ constexpr Score DoubledEarly = S(20, 10);
+ constexpr Score Isolated = S( 2, 15);
+ constexpr Score WeakLever = S( 5, 57);
+ constexpr Score WeakUnopposed = S(16, 22);
// Bonus for blocked pawns at 5th or 6th rank
- constexpr Score BlockedPawn[2] = { S(-10, -3), S(-3, 3) };
+ constexpr Score BlockedPawn[2] = { S(-15, -3), S(-6, 3) };
constexpr Score BlockedStorm[RANK_NB] = {
- S(0, 0), S(0, 0), S(76, 78), S(-10, 15), S(-7, 10), S(-4, 6), S(-1, 2)
+ S(0, 0), S(0, 0), S(75, 78), S(-8, 16), S(-6, 10), S(-6, 6), S(0, 2)
};
// Connected pawn bonus
- constexpr int Connected[RANK_NB] = { 0, 7, 8, 12, 29, 48, 86 };
+ constexpr int Connected[RANK_NB] = { 0, 5, 7, 11, 24, 48, 86 };
// 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( -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) }
+ { V( -5), V( 82), V( 92), V( 54), V( 36), V( 22), V( 28) },
+ { V(-44), V( 63), V( 33), V(-50), V(-30), V(-12), V( -62) },
+ { V(-11), V( 77), V( 22), V( -6), V( 31), V( 8), V( -45) },
+ { V(-39), V(-12), V(-29), V(-50), V(-43), V(-68), V(-164) }
};
// Danger of enemy pawns moving toward our king by [distance from edge][rank].
// is behind our king. Note that UnblockedStorm[0][1-2] accommodate opponent pawn
// on edge, likely blocked by our king.
constexpr Value UnblockedStorm[int(FILE_NB) / 2][RANK_NB] = {
- { V( 85), V(-289), V(-166), V(97), V(50), V( 45), V( 50) },
- { V( 46), V( -25), V( 122), V(45), V(37), V(-10), V( 20) },
- { V( -6), V( 51), V( 168), V(34), V(-2), V(-22), V(-14) },
- { V(-15), V( -11), V( 101), V( 4), V(11), V(-15), V(-29) }
+ { V( 87), V(-288), V(-168), V( 96), V( 47), V( 44), V( 46) },
+ { V( 42), V( -25), V( 120), V( 45), V( 34), V( -9), V( 24) },
+ { V( -8), V( 51), V( 167), V( 35), V( -4), V(-16), V(-12) },
+ { V(-17), V( -13), V( 100), V( 4), V( 9), V(-16), V(-31) }
};
+
+ // KingOnFile[semi-open Us][semi-open Them] contains bonuses/penalties
+ // for king when the king is on a semi-open or open file.
+ constexpr Score KingOnFile[2][2] = {{ S(-21,10), S(-7, 1) },
+ { S( 0,-3), S( 9,-4) }};
+
#undef S
#undef V
constexpr Color Them = ~Us;
constexpr Direction Up = pawn_push(Us);
+ constexpr Direction Down = -Up;
Bitboard neighbours, stoppers, support, phalanx, opposed;
Bitboard lever, leverPush, blocked;
Square s;
bool backward, passed, doubled;
Score score = SCORE_ZERO;
- const Square* pl = pos.squares<PAWN>(Us);
+ Bitboard b = pos.pieces(Us, PAWN);
Bitboard ourPawns = pos.pieces( Us, PAWN);
Bitboard theirPawns = pos.pieces(Them, PAWN);
e->blockedCount += popcount(shift<Up>(ourPawns) & (theirPawns | doubleAttackThem));
// Loop through all pawns of the current color and score each pawn
- while ((s = *pl++) != SQ_NONE)
- {
+ while (b) {
+ s = pop_lsb(&b);
+
assert(pos.piece_on(s) == make_piece(Us, PAWN));
Rank r = relative_rank(Us, s);
phalanx = neighbours & rank_bb(s);
support = neighbours & rank_bb(s - Up);
+ if (doubled)
+ {
+ // Additional doubled penalty if none of their pawns is fixed
+ if (!(ourPawns & shift<Down>(theirPawns | pawn_attacks_bb<Them>(theirPawns))))
+ score -= DoubledEarly;
+ }
+
// A pawn is backward when it is behind all pawns of the same color on
// the adjacent files and cannot safely advance.
backward = !(neighbours & forward_ranks_bb(Them, s + Up))
// Score this pawn
if (support | phalanx)
{
- int v = Connected[r] * (4 + 2 * bool(phalanx) - 2 * bool(opposed) - bool(blocked)) / 2
- + 21 * popcount(support);
+ int v = Connected[r] * (2 + bool(phalanx) - bool(opposed))
+ + 22 * popcount(support);
score += make_score(v, v * (r - 2) / 4);
}
else if (backward)
score -= Backward
- + WeakUnopposed * !opposed;
+ + WeakUnopposed * !opposed * bool(~(FileABB | FileHBB) & s);
if (!support)
score -= Doubled * doubled
+ WeakLever * more_than_one(lever);
- if (blocked && r > RANK_4)
- score += BlockedPawn[r-4];
+ if (blocked && r >= RANK_5)
+ score += BlockedPawn[r - RANK_5];
}
return score;
Score bonus = make_score(5, 5);
- File center = Utility::clamp(file_of(ksq), FILE_B, FILE_G);
+ File center = std::clamp(file_of(ksq), FILE_B, FILE_G);
for (File f = File(center - 1); f <= File(center + 1); ++f)
{
b = ourPawns & file_bb(f);
bonus -= make_score(UnblockedStorm[d][theirRank], 0);
}
+ // King On File
+ bonus -= KingOnFile[pos.is_on_semiopen_file(Us, ksq)][pos.is_on_semiopen_file(Them, ksq)];
+
return bonus;
}
projects / stockfish / blobdiff