X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fevaluate.cpp;h=c507aa06a85f8a2bf4c84e4e038f3d0cdf72fc86;hp=34ebe6c3febbac4ac02771bdeef28424a2245fad;hb=d706ae62d73d90c0f80cdccd58384a347295d549;hpb=f9595828eb7e5e970b0be3ee5f84ddd726845523 diff --git a/src/evaluate.cpp b/src/evaluate.cpp index 34ebe6c3..c507aa06 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -187,11 +187,11 @@ using namespace Trace; namespace { // Threshold for lazy and space evaluation - constexpr Value LazyThreshold1 = Value(1400); - constexpr Value LazyThreshold2 = Value(1300); - constexpr Value SpaceThreshold = Value(12222); - constexpr Value NNUEThreshold1 = Value(550); - constexpr Value NNUEThreshold2 = Value(150); + constexpr Value LazyThreshold1 = Value(1565); + constexpr Value LazyThreshold2 = Value(1102); + constexpr Value SpaceThreshold = Value(11551); + constexpr Value NNUEThreshold1 = Value(682); + constexpr Value NNUEThreshold2 = Value(176); // KingAttackWeights[PieceType] contains king attack weights by piece type constexpr int KingAttackWeights[PIECE_TYPE_NB] = { 0, 0, 81, 52, 44, 10 }; @@ -240,9 +240,8 @@ namespace { S(0, 0), S(9, 28), S(15, 31), S(17, 39), S(64, 70), S(171, 177), S(277, 260) }; - // RookOnFile[semiopen/open] contains bonuses for each rook when there is - // no (friendly) pawn on the rook file. - constexpr Score RookOnFile[] = { S(19, 7), S(48, 27) }; + constexpr Score RookOnClosedFile = S(10, 5); + constexpr Score RookOnOpenFile[] = { S(19, 7), S(48, 27) }; // ThreatByMinor/ByRook[attacked PieceType] contains bonuses according to // which piece type attacks which one. Attacks on lesser pieces which are @@ -388,15 +387,15 @@ namespace { constexpr Direction Down = -pawn_push(Us); constexpr Bitboard OutpostRanks = (Us == WHITE ? Rank4BB | Rank5BB | Rank6BB : Rank5BB | Rank4BB | Rank3BB); - const Square* pl = pos.squares(Us); - + Bitboard b1 = pos.pieces(Us, Pt); Bitboard b, bb; Score score = SCORE_ZERO; attackedBy[Us][Pt] = 0; - for (Square s = *pl; s != SQ_NONE; s = *++pl) - { + while (b1) { + Square s = pop_lsb(&b1); + // Find attacked squares, including x-ray attacks for bishops and rooks b = Pt == BISHOP ? attacks_bb(s, pos.pieces() ^ pos.pieces(QUEEN)) : Pt == ROOK ? attacks_bb< ROOK>(s, pos.pieces() ^ pos.pieces(QUEEN) ^ pos.pieces(Us, ROOK)) @@ -485,16 +484,28 @@ namespace { if (Pt == ROOK) { - // Bonus for rook on an open or semi-open file + // Bonuses for rook on a (semi-)open or closed file if (pos.is_on_semiopen_file(Us, s)) - score += RookOnFile[pos.is_on_semiopen_file(Them, s)]; - - // Penalty when trapped by the king, even more if the king cannot castle - else if (mob <= 3) { - File kf = file_of(pos.square(Us)); - if ((kf < FILE_E) == (file_of(s) < kf)) - score -= TrappedRook * (1 + !pos.castling_rights(Us)); + score += RookOnOpenFile[pos.is_on_semiopen_file(Them, s)]; + } + else + { + // If our pawn on this file is blocked, increase penalty + if ( pos.pieces(Us, PAWN) + & shift(pos.pieces()) + & file_bb(s)) + { + score -= RookOnClosedFile; + } + + // Penalty when trapped by the king, even more if the king cannot castle + if (mob <= 3) + { + File kf = file_of(pos.square(Us)); + if ((kf < FILE_E) == (file_of(s) < kf)) + score -= TrappedRook * (1 + !pos.castling_rights(Us)); + } } } @@ -583,7 +594,7 @@ namespace { int kingFlankDefense = popcount(b3); kingDanger += kingAttackersCount[Them] * kingAttackersWeight[Them] // (~10 Elo) - + 185 * popcount(kingRing[Us] & weak) // (~15 Elo) + + 183 * popcount(kingRing[Us] & weak) // (~15 Elo) + 148 * popcount(unsafeChecks) // (~4 Elo) + 98 * popcount(pos.blockers_for_king(Us)) // (~2 Elo) + 69 * kingAttacksCount[Them] // (~0.5 Elo) @@ -833,6 +844,8 @@ namespace { behind |= shift(behind); behind |= shift(behind); + // Compute space score based on the number of safe squares and number of our pieces + // increased with number of total blocked pawns in position. int bonus = popcount(safe) + popcount(behind & safe & ~attackedBy[Them][ALL_PIECES]); int weight = pos.count(Us) - 3 + std::min(pe->blocked_count(), 9); Score score = make_score(bonus * weight * weight / 16, 0); @@ -894,24 +907,36 @@ namespace { { if (pos.opposite_bishops()) { + // For pure opposite colored bishops endgames use scale factor + // based on the number of passed pawns of the strong side. if ( pos.non_pawn_material(WHITE) == BishopValueMg && pos.non_pawn_material(BLACK) == BishopValueMg) sf = 18 + 4 * popcount(pe->passed_pawns(strongSide)); + // For every other opposite colored bishops endgames use scale factor + // based on the number of all pieces of the strong side. else sf = 22 + 3 * pos.count(strongSide); } + // For rook endgames with strong side not having overwhelming pawn number advantage + // and its pawns being on one flank and weak side protecting its pieces with a king + // use lower scale factor. else if ( pos.non_pawn_material(WHITE) == RookValueMg && pos.non_pawn_material(BLACK) == RookValueMg && pos.count(strongSide) - pos.count(~strongSide) <= 1 && bool(KingSide & pos.pieces(strongSide, PAWN)) != bool(QueenSide & pos.pieces(strongSide, PAWN)) && (attacks_bb(pos.square(~strongSide)) & pos.pieces(~strongSide, PAWN))) sf = 36; + // For queen vs no queen endgames use scale factor + // based on number of minors of side that doesn't have queen. else if (pos.count() == 1) sf = 37 + 3 * (pos.count(WHITE) == 1 ? pos.count(BLACK) + pos.count(BLACK) : pos.count(WHITE) + pos.count(WHITE)); + // In every other case use scale factor based on + // the number of pawns of the strong side reduced if pawns are on a single flank. else sf = std::min(sf, 36 + 7 * pos.count(strongSide)) - 4 * !pawnsOnBothFlanks; + // Reduce scale factor in case of pawns being on a single flank sf -= 4 * !pawnsOnBothFlanks; } @@ -1025,8 +1050,8 @@ Value Eval::evaluate(const Position& pos) { { // Scale and shift NNUE for compatibility with search and classical evaluation auto adjusted_NNUE = [&](){ - int mat = pos.non_pawn_material() + PieceValue[MG][PAWN] * pos.count(); - return NNUE::evaluate(pos) * (720 + mat / 32) / 1024 + Tempo; + int mat = pos.non_pawn_material() + PawnValueMg * pos.count(); + return NNUE::evaluate(pos) * (679 + mat / 32) / 1024 + Tempo; }; // If there is PSQ imbalance use classical eval, with small probability if it is small @@ -1035,16 +1060,20 @@ Value Eval::evaluate(const Position& pos) { bool largePsq = psq * 16 > (NNUEThreshold1 + pos.non_pawn_material() / 64) * r50; bool classical = largePsq || (psq > PawnValueMg / 4 && !(pos.this_thread()->nodes & 0xB)); - v = classical ? Evaluation(pos).value() : adjusted_NNUE(); + // Use classical evaluation for really low piece endgames. + // The most critical case is a bishop + A/H file pawn vs naked king draw. + bool strongClassical = pos.non_pawn_material() < 2 * RookValueMg && pos.count() < 2; + + v = classical || strongClassical ? Evaluation(pos).value() : adjusted_NNUE(); // If the classical eval is small and imbalance large, use NNUE nevertheless. // For the case of opposite colored bishops, switch to NNUE eval with // small probability if the classical eval is less than the threshold. - if ( largePsq - && (abs(v) * 16 < NNUEThreshold2 * r50 - || ( pos.opposite_bishops() - && abs(v) * 16 < (NNUEThreshold1 + pos.non_pawn_material() / 64) * r50 - && !(pos.this_thread()->nodes & 0xB)))) + if ( largePsq && !strongClassical + && ( abs(v) * 16 < NNUEThreshold2 * r50 + || ( pos.opposite_bishops() + && abs(v) * 16 < (NNUEThreshold1 + pos.non_pawn_material() / 64) * r50 + && !(pos.this_thread()->nodes & 0xB)))) v = adjusted_NNUE(); }