#define V Value
#define S(mg, eg) make_score(mg, eg)
- // Isolated pawn penalty
- constexpr Score Isolated = S(13, 18);
-
- // Backward pawn penalty
- constexpr Score Backward = S(24, 12);
+ // Pawn penalties
+ constexpr Score Isolated = S( 4, 20);
+ constexpr Score Backward = S(21, 22);
+ constexpr Score Doubled = S(12, 54);
// Connected pawn bonus by opposed, phalanx, #support and rank
Score Connected[2][2][3][RANK_NB];
- // Doubled pawn penalty
- constexpr Score Doubled = S(18, 38);
-
// 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( -9), V(64), V(77), V( 44), V( 4), V( -1), V(-11) },
- { V(-15), V(83), V(51), V(-10), V( 1), V(-10), V(-28) },
- { V(-18), V(84), V(27), V(-12), V(21), V( -7), V(-36) },
- { V( 12), V(79), V(25), V( 19), V( 9), V( -6), V(-33) }
+ { 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) }
};
- // Danger of enemy pawns moving toward our king by [type][distance from edge][rank].
- // For the unopposed and unblocked cases, RANK_1 = 0 is used when opponent has
- // no pawn on the given file, or their pawn is behind our king.
- constexpr Value StormDanger[][4][RANK_NB] = {
- { { V( 0), V(-290), V(-274), V(57), V(41) }, // BlockedByKing
- { V( 0), V( 60), V( 144), V(39), V(13) },
- { V( 0), V( 65), V( 141), V(41), V(34) },
- { V( 0), V( 53), V( 127), V(56), V(14) } },
- { { V( 4), V( 73), V( 132), V(46), V(31) }, // Unopposed
- { V( 1), V( 64), V( 143), V(26), V(13) },
- { V( 1), V( 47), V( 110), V(44), V(24) },
- { V( 0), V( 72), V( 127), V(50), V(31) } },
- { { V( 0), V( 0), V( 19), V(23), V( 1) }, // BlockedByPawn
- { V( 0), V( 0), V( 88), V(27), V( 2) },
- { V( 0), V( 0), V( 101), V(16), V( 1) },
- { V( 0), V( 0), V( 111), V(22), V(15) } },
- { { V(22), V( 45), V( 104), V(62), V( 6) }, // Unblocked
- { V(31), V( 30), V( 99), V(39), V(19) },
- { V(23), V( 29), V( 96), V(41), V(15) },
- { V(21), V( 23), V( 116), V(41), V(15) } }
+ // 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) }
};
+ // 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
phalanx = neighbours & rank_bb(s);
supported = neighbours & rank_bb(s - Up);
- // A pawn is backward when it is behind all pawns of the same color on the
- // adjacent files and cannot be safely advanced.
- if (!neighbours || lever || relative_rank(Us, s) >= RANK_5)
- backward = false;
- else
- {
- // Find the backmost rank with neighbours or stoppers
- b = rank_bb(backmost_sq(Us, neighbours | stoppers));
-
- // The pawn is backward when it cannot safely progress to that rank:
- // either there is a stopper in the way on this rank, or there is a
- // stopper on adjacent file which controls the way to that rank.
- backward = (b | shift<Up>(b & adjacent_files_bb(f))) & stoppers;
-
- assert(!(backward && (forward_ranks_bb(Them, s + Up) & neighbours)));
- }
+ // A pawn is backward when it is behind all pawns of the same color
+ // on the adjacent files and cannot be safely advanced.
+ backward = !(ourPawns & pawn_attack_span(Them, s + Up))
+ && (stoppers & (leverPush | (s + Up)));
// Passed pawns will be properly scored in evaluation because we need
// full attack info to evaluate them. Include also not passed pawns
void init() {
- static constexpr int Seed[RANK_NB] = { 0, 13, 24, 18, 76, 100, 175, 330 };
+ static constexpr int Seed[RANK_NB] = { 0, 13, 24, 18, 65, 100, 175, 330 };
for (int opposed = 0; opposed <= 1; ++opposed)
for (int phalanx = 0; phalanx <= 1; ++phalanx)
template<Color Us>
Value Entry::evaluate_shelter(const Position& pos, Square ksq) {
- enum { BlockedByKing, Unopposed, BlockedByPawn, Unblocked };
constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
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 ourPawns = b & pos.pieces(Us);
Value safety = (ourPawns & file_bb(ksq)) ? Value(5) : Value(-5);
+ if (shift<Down>(theirPawns) & (FileABB | FileHBB) & BlockRanks & ksq)
+ safety += Value(374);
+
File center = std::max(FILE_B, std::min(FILE_G, file_of(ksq)));
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;
+ int ourRank = b ? relative_rank(Us, backmost_sq(Us, b)) : 0;
b = theirPawns & file_bb(f);
- Rank rkThem = b ? relative_rank(Us, frontmost_sq(Them, b)) : RANK_1;
+ int theirRank = b ? relative_rank(Us, frontmost_sq(Them, b)) : 0;
int d = std::min(f, ~f);
- safety += ShelterStrength[d][rkUs]
- - StormDanger
- [(shift<Down>(b) & ksq) ? BlockedByKing :
- rkUs == RANK_1 ? Unopposed :
- rkThem == (rkUs + 1) ? BlockedByPawn : Unblocked]
- [d][rkThem];
+ safety += ShelterStrength[d][ourRank];
+ safety -= (ourRank && (ourRank == theirRank - 1)) ? BlockedStorm[theirRank]
+ : UnblockedStorm[d][theirRank];
}
return safety;
projects / stockfish / blobdiff