X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fpawns.cpp;h=b26b1be656cda8a599ca2a00d8405fd45317ac9b;hp=523ed15725001933556a20b195573ddcd5143e4e;hb=296534f23489e6d95ba7ce1bb35e8a2cbf9a5a9d;hpb=7de40076ac5b5090f8c74a8bafeae06d6ec20ec3 diff --git a/src/pawns.cpp b/src/pawns.cpp index 523ed157..b26b1be6 100644 --- a/src/pawns.cpp +++ b/src/pawns.cpp @@ -57,26 +57,38 @@ namespace { S( 0, 0), S( 0, 0), S(0, 0), S(0, 0), S(20,20), S(40,40), S(0, 0), S(0, 0) }; - // Bonus for file distance of the two outermost pawns - const Score PawnsFileSpan = S(0, 8); - // Unsupported pawn penalty const Score UnsupportedPawnPenalty = S(20, 10); - // Weakness of our pawn shelter in front of the king indexed by [rank] - const Value ShelterWeakness[RANK_NB] = - { V(100), V(0), V(27), V(73), V(92), V(101), V(101) }; - - // Danger of enemy pawns moving toward our king indexed by - // [no friendly pawn | pawn unblocked | pawn blocked][rank of enemy pawn] - const Value StormDanger[][RANK_NB] = { - { V( 0), V(64), V(128), V(51), V(26) }, - { V(26), V(32), V( 96), V(38), V(20) }, - { V( 0), V( 0), V(160), V(25), V(13) } }; + // Weakness of our pawn shelter in front of the king by [distance from edge][rank] + const Value ShelterWeakness[][RANK_NB] = { + { V(101), V(10), V(24), V(68), V(90), V( 95), V(102) }, + { V(105), V( 1), V(30), V(76), V(95), V(100), V(105) }, + { V( 99), V( 0), V(32), V(72), V(92), V(101), V(100) }, + { V( 94), V( 1), V(31), V(68), V(89), V( 98), V(106) } }; + + // Danger of enemy pawns moving toward our king by [type][distance from edge][rank] + const Value StormDanger[][4][RANK_NB] = { + { { V( 0), V( 61), V( 128), V(47), V(27) }, + { V( 0), V( 66), V( 131), V(49), V(27) }, + { V( 0), V( 62), V( 126), V(52), V(23) }, + { V( 0), V( 63), V( 128), V(52), V(26) } }, + { { V(25), V( 33), V( 95), V(39), V(21) }, + { V(24), V( 33), V( 97), V(42), V(22) }, + { V(24), V( 33), V( 93), V(35), V(23) }, + { V(26), V( 27), V( 96), V(37), V(22) } }, + { { V( 0), V( 0), V( 80), V(14), V( 8) }, + { V( 0), V( 0), V( 163), V(28), V(12) }, + { V( 0), V( 0), V( 163), V(25), V(15) }, + { V( 0), V( 0), V( 161), V(24), V(14) } }, + { { V( 0), V(-300), V(-300), V(54), V(23) }, + { V( 0), V( 67), V( 128), V(46), V(24) }, + { V( 0), V( 64), V( 130), V(50), V(29) }, + { V( 0), V( 63), V( 127), V(51), V(24) } } }; // Max bonus for king safety. Corresponds to start position with all the pawns // in front of the king and no enemy pawn on the horizon. - const Value MaxSafetyBonus = V(263); + const Value MaxSafetyBonus = V(261); #undef S #undef V @@ -168,7 +180,7 @@ namespace { value -= UnsupportedPawnPenalty; if (doubled) - value -= Doubled[f] / rank_distance(s, lsb(doubled)); + value -= Doubled[f] / distance(s, frontmost_sq(Us, doubled)); if (backward) value -= Backward[opposed][f]; @@ -183,10 +195,6 @@ namespace { b = e->semiopenFiles[Us] ^ 0xFF; e->pawnSpan[Us] = b ? int(msb(b) - lsb(b)) : 0; - // In endgame it's better to have pawns on both wings. So give a bonus according - // to file distance between left and right outermost pawns. - value += PawnsFileSpan * e->pawnSpan[Us]; - return value; } @@ -237,15 +245,16 @@ template Value Entry::shelter_storm(const Position& pos, Square ksq) { const Color Them = (Us == WHITE ? BLACK : WHITE); - const Bitboard Edges = (FileABB | FileHBB) & (Rank2BB | Rank3BB); + + enum { NoFriendlyPawn, Unblocked, BlockedByPawn, BlockedByKing }; Bitboard b = pos.pieces(PAWN) & (in_front_bb(Us, rank_of(ksq)) | rank_bb(ksq)); Bitboard ourPawns = b & pos.pieces(Us); Bitboard theirPawns = b & pos.pieces(Them); Value safety = MaxSafetyBonus; - File kf = std::max(FILE_B, std::min(FILE_G, file_of(ksq))); + File center = std::max(FILE_B, std::min(FILE_G, file_of(ksq))); - for (File f = kf - File(1); f <= kf + File(1); ++f) + for (File f = center - File(1); f <= center + File(1); ++f) { b = ourPawns & file_bb(f); Rank rkUs = b ? relative_rank(Us, backmost_sq(Us, b)) : RANK_1; @@ -253,14 +262,12 @@ Value Entry::shelter_storm(const Position& pos, Square ksq) { b = theirPawns & file_bb(f); Rank rkThem = b ? relative_rank(Us, frontmost_sq(Them, b)) : RANK_1; - if ( (Edges & make_square(f, rkThem)) - && file_of(ksq) == f - && relative_rank(Us, ksq) == rkThem - 1) - safety += 200; - else - safety -= ShelterWeakness[rkUs] - + StormDanger[rkUs == RANK_1 ? 0 : - rkThem != rkUs + 1 ? 1 : 2][rkThem]; + safety -= ShelterWeakness[std::min(f, FILE_H - f)][rkUs] + + StormDanger + [f == file_of(ksq) && rkThem == relative_rank(Us, ksq) + 1 ? BlockedByKing : + rkUs == RANK_1 ? NoFriendlyPawn : + rkThem == rkUs + 1 ? BlockedByPawn : Unblocked] + [std::min(f, FILE_H - f)][rkThem]; } return safety; @@ -275,14 +282,14 @@ Score Entry::do_king_safety(const Position& pos, Square ksq) { kingSquares[Us] = ksq; castlingRights[Us] = pos.can_castle(Us); - minKPdistance[Us] = 0; + minKingPawnDistance[Us] = 0; Bitboard pawns = pos.pieces(Us, PAWN); if (pawns) - while (!(DistanceRingsBB[ksq][minKPdistance[Us]++] & pawns)) {} + while (!(DistanceRingsBB[ksq][minKingPawnDistance[Us]++] & pawns)) {} if (relative_rank(Us, ksq) > RANK_4) - return make_score(0, -16 * minKPdistance[Us]); + return make_score(0, -16 * minKingPawnDistance[Us]); Value bonus = shelter_storm(pos, ksq); @@ -293,7 +300,7 @@ Score Entry::do_king_safety(const Position& pos, Square ksq) { if (pos.can_castle(MakeCastling::right)) bonus = std::max(bonus, shelter_storm(pos, relative_square(Us, SQ_C1))); - return make_score(bonus, -16 * minKPdistance[Us]); + return make_score(bonus, -16 * minKingPawnDistance[Us]); } // Explicit template instantiation