X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fevaluate.cpp;h=fee181aeb2c61d9f564ca2d81ecad77ccefc9cf9;hp=c0c7e5ff7098c52b0493ea94693142b9898263db;hb=96362fe3df141eeead4bdb863d2bb2d891886abf;hpb=80ea80e4515e8ed7033ab2a8b22463865fb68979 diff --git a/src/evaluate.cpp b/src/evaluate.cpp index c0c7e5ff..fee181ae 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -29,126 +29,76 @@ #include "material.h" #include "pawns.h" -namespace { - - const Bitboard Center = (FileDBB | FileEBB) & (Rank4BB | Rank5BB); - const Bitboard QueenSide = FileABB | FileBBB | FileCBB | FileDBB; - const Bitboard CenterFiles = FileCBB | FileDBB | FileEBB | FileFBB; - const Bitboard KingSide = FileEBB | FileFBB | FileGBB | FileHBB; - - const Bitboard KingFlank[FILE_NB] = { - QueenSide, QueenSide, QueenSide, CenterFiles, CenterFiles, KingSide, KingSide, KingSide - }; - - namespace Trace { - - enum Tracing {NO_TRACE, TRACE}; - - enum Term { // The first 8 entries are for PieceType - MATERIAL = 8, IMBALANCE, MOBILITY, THREAT, PASSED, SPACE, INITIATIVE, TOTAL, TERM_NB - }; - - double scores[TERM_NB][COLOR_NB][PHASE_NB]; +std::atomic Eval::Contempt; - double to_cp(Value v) { return double(v) / PawnValueEg; } +namespace Trace { - void add(int idx, Color c, Score s) { - scores[idx][c][MG] = to_cp(mg_value(s)); - scores[idx][c][EG] = to_cp(eg_value(s)); - } + enum Tracing { NO_TRACE, TRACE }; - void add(int idx, Score w, Score b = SCORE_ZERO) { - add(idx, WHITE, w); add(idx, BLACK, b); - } + enum Term { // The first 8 entries are reserved for PieceType + MATERIAL = 8, IMBALANCE, MOBILITY, THREAT, PASSED, SPACE, INITIATIVE, TOTAL, TERM_NB + }; - std::ostream& operator<<(std::ostream& os, Term t) { + Score scores[TERM_NB][COLOR_NB]; - if (t == MATERIAL || t == IMBALANCE || t == Term(PAWN) || t == INITIATIVE || t == TOTAL) - os << " --- --- | --- --- | "; - else - os << std::setw(5) << scores[t][WHITE][MG] << " " - << std::setw(5) << scores[t][WHITE][EG] << " | " - << std::setw(5) << scores[t][BLACK][MG] << " " - << std::setw(5) << scores[t][BLACK][EG] << " | "; + double to_cp(Value v) { return double(v) / PawnValueEg; } - os << std::setw(5) << scores[t][WHITE][MG] - scores[t][BLACK][MG] << " " - << std::setw(5) << scores[t][WHITE][EG] - scores[t][BLACK][EG] << " \n"; + void add(int idx, Color c, Score s) { + scores[idx][c] = s; + } - return os; - } + void add(int idx, Score w, Score b = SCORE_ZERO) { + scores[idx][WHITE] = w; + scores[idx][BLACK] = b; } - using namespace Trace; + std::ostream& operator<<(std::ostream& os, Score s) { + os << std::setw(5) << to_cp(mg_value(s)) << " " + << std::setw(5) << to_cp(eg_value(s)); + return os; + } - // Evaluation class contains various information computed and collected - // by the evaluation functions. - template - class Evaluation { + std::ostream& operator<<(std::ostream& os, Term t) { - public: - Evaluation() = delete; - Evaluation(const Position& p) : pos(p) {} - Evaluation& operator=(const Evaluation&) = delete; + if (t == MATERIAL || t == IMBALANCE || t == INITIATIVE || t == TOTAL) + os << " ---- ----" << " | " << " ---- ----"; + else + os << scores[t][WHITE] << " | " << scores[t][BLACK]; - Value value(); + os << " | " << scores[t][WHITE] - scores[t][BLACK] << "\n"; + return os; + } +} - private: - // Evaluation helpers (used when calling value()) - template void initialize(); - template Score evaluate_king(); - template Score evaluate_threats(); - int king_distance(Color c, Square s); - template Score evaluate_passed_pawns(); - template Score evaluate_space(); - template Score evaluate_pieces(); - ScaleFactor evaluate_scale_factor(Value eg); - Score evaluate_initiative(Value eg); - - // Data members - const Position& pos; - Material::Entry* me; - Pawns::Entry* pe; - Bitboard mobilityArea[COLOR_NB]; - Score mobility[COLOR_NB] = { SCORE_ZERO, SCORE_ZERO }; +using namespace Trace; - // attackedBy[color][piece type] is a bitboard representing all squares - // attacked by a given color and piece type. Special "piece types" which are - // also calculated are QUEEN_DIAGONAL and ALL_PIECES. - Bitboard attackedBy[COLOR_NB][PIECE_TYPE_NB]; +namespace { - // attackedBy2[color] are the squares attacked by 2 pieces of a given color, - // possibly via x-ray or by one pawn and one piece. Diagonal x-ray through - // pawn or squares attacked by 2 pawns are not explicitly added. - Bitboard attackedBy2[COLOR_NB]; + const Bitboard QueenSide = FileABB | FileBBB | FileCBB | FileDBB; + const Bitboard CenterFiles = FileCBB | FileDBB | FileEBB | FileFBB; + const Bitboard KingSide = FileEBB | FileFBB | FileGBB | FileHBB; + const Bitboard Center = (FileDBB | FileEBB) & (Rank4BB | Rank5BB); - // kingRing[color] is the zone around the king which is considered - // by the king safety evaluation. This consists of the squares directly - // adjacent to the king, and (only for a king on its first rank) the - // squares two ranks in front of the king. For instance, if black's king - // is on g8, kingRing[BLACK] is a bitboard containing the squares f8, h8, - // f7, g7, h7, f6, g6 and h6. - Bitboard kingRing[COLOR_NB]; + const Bitboard KingFlank[FILE_NB] = { + QueenSide, QueenSide, QueenSide, + CenterFiles, CenterFiles, + KingSide, KingSide, KingSide + }; - // kingAttackersCount[color] is the number of pieces of the given color - // which attack a square in the kingRing of the enemy king. - int kingAttackersCount[COLOR_NB]; + // Threshold for lazy and space evaluation + const Value LazyThreshold = Value(1500); + const Value SpaceThreshold = Value(12222); - // kingAttackersWeight[color] is the sum of the "weights" of the pieces of the - // given color which attack a square in the kingRing of the enemy king. The - // weights of the individual piece types are given by the elements in the - // KingAttackWeights array. - int kingAttackersWeight[COLOR_NB]; + // KingAttackWeights[PieceType] contains king attack weights by piece type + const int KingAttackWeights[PIECE_TYPE_NB] = { 0, 0, 78, 56, 45, 11 }; - // kingAdjacentZoneAttacksCount[color] is the number of attacks by the given - // color to squares directly adjacent to the enemy king. Pieces which attack - // more than one square are counted multiple times. For instance, if there is - // a white knight on g5 and black's king is on g8, this white knight adds 2 - // to kingAdjacentZoneAttacksCount[WHITE]. - int kingAdjacentZoneAttacksCount[COLOR_NB]; - }; + // Penalties for enemy's safe checks + const int QueenSafeCheck = 780; + const int RookSafeCheck = 880; + const int BishopSafeCheck = 435; + const int KnightSafeCheck = 790; - #define V(v) Value(v) - #define S(mg, eg) make_score(mg, eg) +#define S(mg, eg) make_score(mg, eg) // MobilityBonus[PieceType-2][attacked] contains bonuses for middle and end game, // indexed by piece type and number of attacked squares in the mobility area. @@ -169,16 +119,15 @@ namespace { }; // Outpost[knight/bishop][supported by pawn] contains bonuses for minor - // pieces if they can reach an outpost square, bigger if that square is - // supported by a pawn. If the minor piece occupies an outpost square - // then score is doubled. + // pieces if they occupy or can reach an outpost square, bigger if that + // square is supported by a pawn. const Score Outpost[][2] = { { S(22, 6), S(36,12) }, // Knight { S( 9, 2), S(15, 5) } // Bishop }; - // RookOnFile[semiopen/open] contains bonuses for each rook when there is no - // friendly pawn on the rook file. + // RookOnFile[semiopen/open] contains bonuses for each rook when there is + // no (friendly) pawn on the rook file. const Score RookOnFile[] = { S(20, 7), S(45, 20) }; // ThreatByMinor/ByRook[attacked PieceType] contains bonuses according to @@ -196,63 +145,108 @@ namespace { // pawns or pieces which are not pawn-defended. const Score ThreatByKing[] = { S(3, 65), S(9, 145) }; - // Passed[mg/eg][Rank] contains midgame and endgame bonuses for passed pawns. - // We don't use a Score because we process the two components independently. - const Value Passed[][RANK_NB] = { - { V(0), V(5), V( 5), V(32), V(70), V(172), V(217) }, - { V(0), V(7), V(13), V(42), V(70), V(170), V(269) } + // PassedRank[Rank] contains a bonus according to the rank of a passed pawn + const Score PassedRank[RANK_NB] = { + S(0, 0), S(5, 7), S(5, 13), S(32, 42), S(70, 70), S(172, 170), S(217, 269) }; // PassedFile[File] contains a bonus according to the file of a passed pawn const Score PassedFile[FILE_NB] = { - S( 9, 10), S( 2, 10), S( 1, -8), S(-20,-12), - S(-20,-12), S( 1, -8), S( 2, 10), S( 9, 10) + S( 9, 10), S(2, 10), S(1, -8), S(-20,-12), + S(-20,-12), S(1, -8), S(2, 10), S( 9, 10) }; - // Rank factor applied on some bonus for passed pawn on rank 4 or beyond - const int RankFactor[RANK_NB] = {0, 0, 0, 2, 7, 12, 19}; - - // KingProtector[PieceType-2] contains a bonus according to distance from king - const Score KingProtector[] = { S(-3, -5), S(-4, -3), S(-3, 0), S(-1, 1) }; - - // Assorted bonuses and penalties used by evaluation - const Score MinorBehindPawn = S( 16, 0); - const Score BishopPawns = S( 8, 12); - const Score LongRangedBishop = S( 22, 0); - const Score RookOnPawn = S( 8, 24); - const Score TrappedRook = S( 92, 0); - const Score WeakQueen = S( 50, 10); - const Score CloseEnemies = S( 7, 0); - const Score PawnlessFlank = S( 20, 80); - const Score ThreatBySafePawn = S(175,168); - const Score ThreatByRank = S( 16, 3); - const Score Hanging = S( 52, 30); - const Score WeakUnopposedPawn = S( 5, 25); - const Score ThreatByPawnPush = S( 47, 26); - const Score ThreatByAttackOnQueen = S( 42, 21); - const Score HinderPassedPawn = S( 8, 1); - const Score TrappedBishopA1H1 = S( 50, 50); - - #undef S - #undef V + // PassedDanger[Rank] contains a term to weight the passed score + const int PassedDanger[RANK_NB] = { 0, 0, 0, 2, 7, 12, 19 }; + + // KingProtector[PieceType-2] contains a penalty according to distance from king + const Score KingProtector[] = { S(3, 5), S(4, 3), S(3, 0), S(1, -1) }; + + // Assorted bonuses and penalties + const Score BishopPawns = S( 8, 12); + const Score CloseEnemies = S( 7, 0); + const Score Connectivity = S( 3, 1); + const Score CorneredBishop = S( 50, 50); + const Score Hanging = S( 52, 30); + const Score HinderPassedPawn = S( 8, 1); + const Score KnightOnQueen = S( 21, 11); + const Score LongDiagonalBishop = S( 22, 0); + const Score MinorBehindPawn = S( 16, 0); + const Score PawnlessFlank = S( 20, 80); + const Score RookOnPawn = S( 8, 24); + const Score SliderOnQueen = S( 42, 21); + const Score ThreatByPawnPush = S( 47, 26); + const Score ThreatByRank = S( 16, 3); + const Score ThreatBySafePawn = S(175,168); + const Score TrappedRook = S( 92, 0); + const Score WeakQueen = S( 50, 10); + const Score WeakUnopposedPawn = S( 5, 25); + +#undef S + + // Evaluation class computes and stores attacks tables and other working data + template + class Evaluation { - // KingAttackWeights[PieceType] contains king attack weights by piece type - const int KingAttackWeights[PIECE_TYPE_NB] = { 0, 0, 78, 56, 45, 11 }; + public: + Evaluation() = delete; + explicit Evaluation(const Position& p) : pos(p) {} + Evaluation& operator=(const Evaluation&) = delete; + Value value(); - // Penalties for enemy's safe checks - const int QueenSafeCheck = 780; - const int RookSafeCheck = 880; - const int BishopSafeCheck = 435; - const int KnightSafeCheck = 790; + private: + template void initialize(); + template Score pieces(); + template Score king() const; + template Score threats() const; + template Score passed() const; + template Score space() const; + ScaleFactor scale_factor(Value eg) const; + Score initiative(Value eg) const; - // Threshold for lazy and space evaluation - const Value LazyThreshold = Value(1500); - const Value SpaceThreshold = Value(12222); + const Position& pos; + Material::Entry* me; + Pawns::Entry* pe; + Bitboard mobilityArea[COLOR_NB]; + Score mobility[COLOR_NB] = { SCORE_ZERO, SCORE_ZERO }; + + // attackedBy[color][piece type] is a bitboard representing all squares + // attacked by a given color and piece type. Special "piece types" which + // is also calculated is ALL_PIECES. + Bitboard attackedBy[COLOR_NB][PIECE_TYPE_NB]; + + // attackedBy2[color] are the squares attacked by 2 pieces of a given color, + // possibly via x-ray or by one pawn and one piece. Diagonal x-ray through + // pawn or squares attacked by 2 pawns are not explicitly added. + Bitboard attackedBy2[COLOR_NB]; + + // kingRing[color] are the squares adjacent to the king, plus (only for a + // king on its first rank) the squares two ranks in front. For instance, + // if black's king is on g8, kingRing[BLACK] is f8, h8, f7, g7, h7, f6, g6 + // and h6. It is set to 0 when king safety evaluation is skipped. + Bitboard kingRing[COLOR_NB]; + + // kingAttackersCount[color] is the number of pieces of the given color + // which attack a square in the kingRing of the enemy king. + int kingAttackersCount[COLOR_NB]; + + // kingAttackersWeight[color] is the sum of the "weights" of the pieces of + // the given color which attack a square in the kingRing of the enemy king. + // The weights of the individual piece types are given by the elements in + // the KingAttackWeights array. + int kingAttackersWeight[COLOR_NB]; + // kingAttacksCount[color] is the number of attacks by the given color to + // squares directly adjacent to the enemy king. Pieces which attack more + // than one square are counted multiple times. For instance, if there is + // a white knight on g5 and black's king is on g8, this white knight adds 2 + // to kingAttacksCount[WHITE]. + int kingAttacksCount[COLOR_NB]; + }; - // initialize() computes king and pawn attacks, and the king ring bitboard - // for a given color. This is done at the beginning of the evaluation. + // Evaluation::initialize() computes king and pawn attacks, and the king ring + // bitboard for a given color. This is done at the beginning of the evaluation. template template void Evaluation::initialize() { @@ -261,40 +255,37 @@ namespace { const Direction Down = (Us == WHITE ? SOUTH : NORTH); const Bitboard LowRanks = (Us == WHITE ? Rank2BB | Rank3BB: Rank7BB | Rank6BB); - // Find our pawns on the first two ranks, and those which are blocked + // Find our pawns that are blocked or on the first two ranks Bitboard b = pos.pieces(Us, PAWN) & (shift(pos.pieces()) | LowRanks); // Squares occupied by those pawns, by our king, or controlled by enemy pawns // are excluded from the mobility area. mobilityArea[Us] = ~(b | pos.square(Us) | pe->pawn_attacks(Them)); - // Initialise the attack bitboards with the king and pawn information - b = attackedBy[Us][KING] = pos.attacks_from(pos.square(Us)); + // Initialise attackedBy bitboards for kings and pawns + attackedBy[Us][KING] = pos.attacks_from(pos.square(Us)); attackedBy[Us][PAWN] = pe->pawn_attacks(Us); - - attackedBy2[Us] = b & attackedBy[Us][PAWN]; - attackedBy[Us][ALL_PIECES] = b | attackedBy[Us][PAWN]; + attackedBy[Us][ALL_PIECES] = attackedBy[Us][KING] | attackedBy[Us][PAWN]; + attackedBy2[Us] = attackedBy[Us][KING] & attackedBy[Us][PAWN]; // Init our king safety tables only if we are going to use them if (pos.non_pawn_material(Them) >= RookValueMg + KnightValueMg) { - kingRing[Us] = b; + kingRing[Us] = attackedBy[Us][KING]; if (relative_rank(Us, pos.square(Us)) == RANK_1) - kingRing[Us] |= shift(b); + kingRing[Us] |= shift(kingRing[Us]); - kingAttackersCount[Them] = popcount(b & pe->pawn_attacks(Them)); - kingAdjacentZoneAttacksCount[Them] = kingAttackersWeight[Them] = 0; + kingAttackersCount[Them] = popcount(attackedBy[Us][KING] & pe->pawn_attacks(Them)); + kingAttacksCount[Them] = kingAttackersWeight[Them] = 0; } else kingRing[Us] = kingAttackersCount[Them] = 0; } - // evaluate_pieces() assigns bonuses and penalties to the pieces of a given - // color and type. - - template template - Score Evaluation::evaluate_pieces() { + // Evaluation::pieces() scores pieces of a given color and type + template template + Score Evaluation::pieces() { const Color Them = (Us == WHITE ? BLACK : WHITE); const Bitboard OutpostRanks = (Us == WHITE ? Rank4BB | Rank5BB | Rank6BB @@ -307,9 +298,6 @@ namespace { attackedBy[Us][Pt] = 0; - if (Pt == QUEEN) - attackedBy[Us][QUEEN_DIAGONAL] = 0; - while ((s = *pl++) != SQ_NONE) { // Find attacked squares, including x-ray attacks for bishops and rooks @@ -317,41 +305,36 @@ namespace { : Pt == ROOK ? attacks_bb< ROOK>(s, pos.pieces() ^ pos.pieces(QUEEN) ^ pos.pieces(Us, ROOK)) : pos.attacks_from(s); - if (pos.pinned_pieces(Us) & s) + if (pos.blockers_for_king(Us) & s) b &= LineBB[pos.square(Us)][s]; attackedBy2[Us] |= attackedBy[Us][ALL_PIECES] & b; - attackedBy[Us][ALL_PIECES] |= attackedBy[Us][Pt] |= b; - - if (Pt == QUEEN) - attackedBy[Us][QUEEN_DIAGONAL] |= b & PseudoAttacks[BISHOP][s]; + attackedBy[Us][Pt] |= b; + attackedBy[Us][ALL_PIECES] |= b; if (b & kingRing[Them]) { kingAttackersCount[Us]++; kingAttackersWeight[Us] += KingAttackWeights[Pt]; - kingAdjacentZoneAttacksCount[Us] += popcount(b & attackedBy[Them][KING]); + kingAttacksCount[Us] += popcount(b & attackedBy[Them][KING]); } int mob = popcount(b & mobilityArea[Us]); mobility[Us] += MobilityBonus[Pt - 2][mob]; - // Bonus for this piece as a king protector - score += KingProtector[Pt - 2] * distance(s, pos.square(Us)); + // Penalty if the piece is far from the king + score -= KingProtector[Pt - 2] * distance(s, pos.square(Us)); if (Pt == BISHOP || Pt == KNIGHT) { - // Bonus for outpost squares + // Bonus if piece is on an outpost square or can reach one bb = OutpostRanks & ~pe->pawn_attacks_span(Them); if (bb & s) score += Outpost[Pt == BISHOP][bool(attackedBy[Us][PAWN] & s)] * 2; - else - { - bb &= b & ~pos.pieces(Us); - if (bb) - score += Outpost[Pt == BISHOP][bool(attackedBy[Us][PAWN] & bb)]; - } + + else if (bb &= b & ~pos.pieces(Us)) + score += Outpost[Pt == BISHOP][bool(attackedBy[Us][PAWN] & bb)]; // Bonus when behind a pawn if ( relative_rank(Us, s) < RANK_5 @@ -360,12 +343,12 @@ namespace { if (Pt == BISHOP) { - // Penalty for pawns on the same color square as the bishop + // Penalty according to number of pawns on the same color square as the bishop score -= BishopPawns * pe->pawns_on_same_color_squares(Us, s); // Bonus for bishop on a long diagonal which can "see" both center squares if (more_than_one(Center & (attacks_bb(s, pos.pieces(PAWN)) | s))) - score += LongRangedBishop; + score += LongDiagonalBishop; } // An important Chess960 pattern: A cornered bishop blocked by a friendly @@ -377,19 +360,19 @@ namespace { { Direction d = pawn_push(Us) + (file_of(s) == FILE_A ? EAST : WEST); if (pos.piece_on(s + d) == make_piece(Us, PAWN)) - score -= !pos.empty(s + d + pawn_push(Us)) ? TrappedBishopA1H1 * 4 - : pos.piece_on(s + d + d) == make_piece(Us, PAWN) ? TrappedBishopA1H1 * 2 - : TrappedBishopA1H1; + score -= !pos.empty(s + d + pawn_push(Us)) ? CorneredBishop * 4 + : pos.piece_on(s + d + d) == make_piece(Us, PAWN) ? CorneredBishop * 2 + : CorneredBishop; } } if (Pt == ROOK) { - // Bonus for aligning with enemy pawns on the same rank/file + // Bonus for aligning rook with with enemy pawns on the same rank/file if (relative_rank(Us, s) >= RANK_5) score += RookOnPawn * popcount(pos.pieces(Them, PAWN) & PseudoAttacks[ROOK][s]); - // Bonus when on an open or semi-open file + // Bonus for rook on an open or semi-open file if (pe->semiopen_file(Us, file_of(s))) score += RookOnFile[bool(pe->semiopen_file(Them, file_of(s)))]; @@ -397,7 +380,6 @@ namespace { else if (mob <= 3) { File kf = file_of(pos.square(Us)); - if ((kf < FILE_E) == (file_of(s) < kf)) score -= (TrappedRook - make_score(mob * 22, 0)) * (1 + !pos.can_castle(Us)); } @@ -406,12 +388,11 @@ namespace { if (Pt == QUEEN) { // Penalty if any relative pin or discovered attack against the queen - Bitboard pinners; - if (pos.slider_blockers(pos.pieces(Them, ROOK, BISHOP), s, pinners)) + Bitboard queenPinners; + if (pos.slider_blockers(pos.pieces(Them, ROOK, BISHOP), s, queenPinners)) score -= WeakQueen; } } - if (T) Trace::add(Pt, Us, score); @@ -419,30 +400,29 @@ namespace { } - // evaluate_king() assigns bonuses and penalties to a king of a given color + // Evaluation::king() assigns bonuses and penalties to a king of a given color + template template + Score Evaluation::king() const { - template template - Score Evaluation::evaluate_king() { - - const Color Them = (Us == WHITE ? BLACK : WHITE); - const Bitboard Camp = (Us == WHITE ? AllSquares ^ Rank6BB ^ Rank7BB ^ Rank8BB - : AllSquares ^ Rank1BB ^ Rank2BB ^ Rank3BB); + const Color Them = (Us == WHITE ? BLACK : WHITE); + const Bitboard Camp = (Us == WHITE ? AllSquares ^ Rank6BB ^ Rank7BB ^ Rank8BB + : AllSquares ^ Rank1BB ^ Rank2BB ^ Rank3BB); const Square ksq = pos.square(Us); - Bitboard weak, b, b1, b2, safe, unsafeChecks; + Bitboard weak, b, b1, b2, safe, unsafeChecks, pinned; // King shelter and enemy pawns storm Score score = pe->king_safety(pos, ksq); // Main king safety evaluation - if (kingAttackersCount[Them] > (1 - pos.count(Them))) + if (kingAttackersCount[Them] > 1 - pos.count(Them)) { + int kingDanger = unsafeChecks = 0; + // Attacked squares defended at most once by our queen or king weak = attackedBy[Them][ALL_PIECES] & ~attackedBy2[Us] - & (attackedBy[Us][KING] | attackedBy[Us][QUEEN] | ~attackedBy[Us][ALL_PIECES]); - - int kingDanger = unsafeChecks = 0; + & (~attackedBy[Us][ALL_PIECES] | attackedBy[Us][KING] | attackedBy[Us][QUEEN]); // Analyse the safe enemy's checks which are possible on next move safe = ~pos.pieces(Them); @@ -480,11 +460,12 @@ namespace { // Unsafe or occupied checking squares will also be considered, as long as // the square is in the attacker's mobility area. unsafeChecks &= mobilityArea[Them]; + pinned = pos.blockers_for_king(Us) & pos.pieces(Us); kingDanger += kingAttackersCount[Them] * kingAttackersWeight[Them] - + 102 * kingAdjacentZoneAttacksCount[Them] + + 102 * kingAttacksCount[Them] + 191 * popcount(kingRing[Us] & weak) - + 143 * popcount(pos.pinned_pieces(Us) | unsafeChecks) + + 143 * popcount(pinned | unsafeChecks) - 848 * !pos.count(Them) - 9 * mg_value(score) / 8 + 40; @@ -498,24 +479,20 @@ namespace { } } - // King tropism: firstly, find squares that opponent attacks in our king flank - File kf = file_of(ksq); - b = attackedBy[Them][ALL_PIECES] & KingFlank[kf] & Camp; - - assert(((Us == WHITE ? b << 4 : b >> 4) & b) == 0); - assert(popcount(Us == WHITE ? b << 4 : b >> 4) == popcount(b)); - - // Secondly, add the squares which are attacked twice in that flank and - // which are not defended by our pawns. - b = (Us == WHITE ? b << 4 : b >> 4) - | (b & attackedBy2[Them] & ~attackedBy[Us][PAWN]); - - score -= CloseEnemies * popcount(b); + Bitboard kf = KingFlank[file_of(ksq)]; // Penalty when our king is on a pawnless flank - if (!(pos.pieces(PAWN) & KingFlank[kf])) + if (!(pos.pieces(PAWN) & kf)) score -= PawnlessFlank; + // Find the squares that opponent attacks in our king flank, and the squares + // which are attacked twice in that flank but not defended by our pawns. + b1 = attackedBy[Them][ALL_PIECES] & kf & Camp; + b2 = b1 & attackedBy2[Them] & ~attackedBy[Us][PAWN]; + + // King tropism, to anticipate slow motion attacks on our king + score -= CloseEnemies * (popcount(b1) + popcount(b2)); + if (T) Trace::add(KING, Us, score); @@ -523,49 +500,44 @@ namespace { } - // evaluate_threats() assigns bonuses according to the types of the attacking - // and the attacked pieces. - - template template - Score Evaluation::evaluate_threats() { + // Evaluation::threats() assigns bonuses according to the types of the + // attacking and the attacked pieces. + template template + Score Evaluation::threats() const { - const Color Them = (Us == WHITE ? BLACK : WHITE); - const Direction Up = (Us == WHITE ? NORTH : SOUTH); - const Direction Left = (Us == WHITE ? NORTH_WEST : SOUTH_EAST); - const Direction Right = (Us == WHITE ? NORTH_EAST : SOUTH_WEST); - const Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB); + const Color Them = (Us == WHITE ? BLACK : WHITE); + const Direction Up = (Us == WHITE ? NORTH : SOUTH); + const Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB); - Bitboard b, weak, defended, stronglyProtected, safeThreats; + Bitboard b, weak, defended, nonPawnEnemies, stronglyProtected, safeThreats; Score score = SCORE_ZERO; // Non-pawn enemies attacked by a pawn - weak = (pos.pieces(Them) ^ pos.pieces(Them, PAWN)) & attackedBy[Us][PAWN]; + nonPawnEnemies = pos.pieces(Them) ^ pos.pieces(Them, PAWN); + weak = nonPawnEnemies & attackedBy[Us][PAWN]; if (weak) { - b = pos.pieces(Us, PAWN) & ( ~attackedBy[Them][ALL_PIECES] - | attackedBy[Us][ALL_PIECES]); - - safeThreats = (shift(b) | shift(b)) & weak; + // Our safe or protected pawns + b = pos.pieces(Us, PAWN) + & (~attackedBy[Them][ALL_PIECES] | attackedBy[Us][ALL_PIECES]); + safeThreats = pawn_attacks_bb(b) & weak; score += ThreatBySafePawn * popcount(safeThreats); } - // Squares strongly protected by the opponent, either because they attack the - // square with a pawn, or because they attack the square twice and we don't. + // Squares strongly protected by the enemy, either because they defend the + // square with a pawn, or because they defend the square twice and we don't. stronglyProtected = attackedBy[Them][PAWN] | (attackedBy2[Them] & ~attackedBy2[Us]); // Non-pawn enemies, strongly protected - defended = (pos.pieces(Them) ^ pos.pieces(Them, PAWN)) - & stronglyProtected; + defended = nonPawnEnemies & stronglyProtected; // Enemies not strongly protected and under our attack - weak = pos.pieces(Them) - & ~stronglyProtected - & attackedBy[Us][ALL_PIECES]; + weak = pos.pieces(Them) & ~stronglyProtected & attackedBy[Us][ALL_PIECES]; - // Add a bonus according to the kind of attacking pieces + // Bonus according to the kind of attacking pieces if (defended | weak) { b = (defended | weak) & (attackedBy[Us][KNIGHT] | attackedBy[Us][BISHOP]); @@ -593,7 +565,7 @@ namespace { score += ThreatByKing[more_than_one(b)]; } - // Bonus for opponent unopposed weak pawns + // Bonus for enemy unopposed weak pawns if (pos.pieces(Us, ROOK, QUEEN)) score += WeakUnopposedPawn * pe->weak_unopposed(Them); @@ -605,19 +577,32 @@ namespace { b &= ~attackedBy[Them][PAWN] & (attackedBy[Us][ALL_PIECES] | ~attackedBy[Them][ALL_PIECES]); - // Add a bonus for each new pawn threats from those squares - b = (shift(b) | shift(b)) + // Bonus for safe pawn threats on the next move + b = pawn_attacks_bb(b) & pos.pieces(Them) & ~attackedBy[Us][PAWN]; score += ThreatByPawnPush * popcount(b); - // Add a bonus for safe slider attack threats on opponent queen - safeThreats = ~pos.pieces(Us) & ~attackedBy2[Them] & attackedBy2[Us]; - b = (attackedBy[Us][BISHOP] & attackedBy[Them][QUEEN_DIAGONAL]) - | (attackedBy[Us][ROOK ] & attackedBy[Them][QUEEN] & ~attackedBy[Them][QUEEN_DIAGONAL]); + // Bonus for threats on the next moves against enemy queen + if (pos.count(Them) == 1) + { + Square s = pos.square(Them); + safeThreats = mobilityArea[Us] & ~stronglyProtected; + + b = attackedBy[Us][KNIGHT] & pos.attacks_from(s); - score += ThreatByAttackOnQueen * popcount(b & safeThreats); + score += KnightOnQueen * popcount(b & safeThreats); + + b = (attackedBy[Us][BISHOP] & pos.attacks_from(s)) + | (attackedBy[Us][ROOK ] & pos.attacks_from(s)); + + score += SliderOnQueen * popcount(b & safeThreats & attackedBy2[Us]); + } + + // Connectivity: ensure that knights, bishops, rooks, and queens are protected + b = (pos.pieces(Us) ^ pos.pieces(Us, PAWN, KING)) & attackedBy[Us][ALL_PIECES]; + score += Connectivity * popcount(b); if (T) Trace::add(THREAT, Us, score); @@ -625,22 +610,19 @@ namespace { return score; } - // king_distance() returns an estimate of the distance that the king - // of the given color has to run to reach square s. - template - int Evaluation::king_distance(Color c, Square s) { - return std::min(distance(pos.square(c), s), 5); - } - - // evaluate_passed_pawns() evaluates the passed pawns and candidate passed + // Evaluation::passed() evaluates the passed pawns and candidate passed // pawns of the given color. - template template - Score Evaluation::evaluate_passed_pawns() { + template template + Score Evaluation::passed() const { const Color Them = (Us == WHITE ? BLACK : WHITE); const Direction Up = (Us == WHITE ? NORTH : SOUTH); + auto king_proximity = [&](Color c, Square s) { + return std::min(distance(pos.square(c), s), 5); + }; + Bitboard b, bb, squaresToQueen, defendedSquares, unsafeSquares; Score score = SCORE_ZERO; @@ -656,20 +638,21 @@ namespace { score -= HinderPassedPawn * popcount(bb); int r = relative_rank(Us, s); - int rr = RankFactor[r]; + int w = PassedDanger[r]; - Value mbonus = Passed[MG][r], ebonus = Passed[EG][r]; + Score bonus = PassedRank[r]; - if (rr) + if (w) { Square blockSq = s + Up; // Adjust bonus based on the king's proximity - ebonus += (king_distance(Them, blockSq) * 5 - king_distance(Us, blockSq) * 2) * rr; + bonus += make_score(0, ( king_proximity(Them, blockSq) * 5 + - king_proximity(Us, blockSq) * 2) * w); // If blockSq is not the queening square then consider also a second push if (r != RANK_7) - ebonus -= king_distance(Us, blockSq + Up) * rr; + bonus -= make_score(0, king_proximity(Us, blockSq + Up) * w); // If the pawn is free to advance, then increase the bonus if (pos.empty(blockSq)) @@ -699,18 +682,19 @@ namespace { else if (defendedSquares & blockSq) k += 4; - mbonus += k * rr, ebonus += k * rr; + bonus += make_score(k * w, k * w); } else if (pos.pieces(Us) & blockSq) - mbonus += rr + r * 2, ebonus += rr + r * 2; + bonus += make_score(w + r * 2, w + r * 2); } // rr != 0 // Scale down bonus for candidate passers which need more than one // pawn push to become passed or have a pawn in front of them. - if (!pos.pawn_passed(Us, s + Up) || (pos.pieces(PAWN) & forward_file_bb(Us, s))) - mbonus /= 2, ebonus /= 2; + if ( !pos.pawn_passed(Us, s + Up) + || (pos.pieces(PAWN) & forward_file_bb(Us, s))) + bonus = bonus / 2; - score += make_score(mbonus, ebonus) + PassedFile[file_of(s)]; + score += bonus + PassedFile[file_of(s)]; } if (T) @@ -720,21 +704,24 @@ namespace { } - // evaluate_space() computes the space evaluation for a given side. The + // Evaluation::space() computes the space evaluation for a given side. The // space evaluation is a simple bonus based on the number of safe squares // available for minor pieces on the central four files on ranks 2--4. Safe // squares one, two or three squares behind a friendly pawn are counted // twice. Finally, the space bonus is multiplied by a weight. The aim is to // improve play on game opening. - template template - Score Evaluation::evaluate_space() { + template template + Score Evaluation::space() const { const Color Them = (Us == WHITE ? BLACK : WHITE); const Bitboard SpaceMask = Us == WHITE ? CenterFiles & (Rank2BB | Rank3BB | Rank4BB) : CenterFiles & (Rank7BB | Rank6BB | Rank5BB); + if (pos.non_pawn_material() < SpaceThreshold) + return SCORE_ZERO; + // Find the safe squares for our pieces inside the area defined by // SpaceMask. A square is unsafe if it is attacked by an enemy // pawn, or if it is undefended and attacked by an enemy piece. @@ -748,35 +735,43 @@ namespace { behind |= (Us == WHITE ? behind >> 8 : behind << 8); behind |= (Us == WHITE ? behind >> 16 : behind << 16); - // Since SpaceMask[Us] is fully on our half of the board... - assert(unsigned(safe >> (Us == WHITE ? 32 : 0)) == 0); - - // ...count safe + (behind & safe) with a single popcount. - int bonus = popcount((Us == WHITE ? safe << 32 : safe >> 32) | (behind & safe)); + int bonus = popcount(safe) + popcount(behind & safe); int weight = pos.count(Us) - 2 * pe->open_files(); - return make_score(bonus * weight * weight / 16, 0); + Score score = make_score(bonus * weight * weight / 16, 0); + + if (T) + Trace::add(SPACE, Us, score); + + return score; } - // evaluate_initiative() computes the initiative correction value for the - // position, i.e., second order bonus/malus based on the known attacking/defending - // status of the players. + // Evaluation::initiative() computes the initiative correction value + // for the position. It is a second order bonus/malus based on the + // known attacking/defending status of the players. template - Score Evaluation::evaluate_initiative(Value eg) { + Score Evaluation::initiative(Value eg) const { + + int outflanking = distance(pos.square(WHITE), pos.square(BLACK)) + - distance(pos.square(WHITE), pos.square(BLACK)); - int kingDistance = distance(pos.square(WHITE), pos.square(BLACK)) - - distance(pos.square(WHITE), pos.square(BLACK)); - bool bothFlanks = (pos.pieces(PAWN) & QueenSide) && (pos.pieces(PAWN) & KingSide); + bool pawnsOnBothFlanks = (pos.pieces(PAWN) & QueenSide) + && (pos.pieces(PAWN) & KingSide); // Compute the initiative bonus for the attacking side - int initiative = 8 * (pe->pawn_asymmetry() + kingDistance - 17) + 12 * pos.count() + 16 * bothFlanks; + int complexity = 8 * outflanking + + 8 * pe->pawn_asymmetry() + + 12 * pos.count() + + 16 * pawnsOnBothFlanks + + 48 * !pos.non_pawn_material() + -136 ; // Now apply the bonus: note that we find the attacking side by extracting // the sign of the endgame value, and that we carefully cap the bonus so // that the endgame score will never change sign after the bonus. - int v = ((eg > 0) - (eg < 0)) * std::max(initiative, -abs(eg)); + int v = ((eg > 0) - (eg < 0)) * std::max(complexity, -abs(eg)); if (T) Trace::add(INITIATIVE, make_score(0, v)); @@ -785,13 +780,13 @@ namespace { } - // evaluate_scale_factor() computes the scale factor for the winning side + // Evaluation::scale_factor() computes the scale factor for the winning side template - ScaleFactor Evaluation::evaluate_scale_factor(Value eg) { + ScaleFactor Evaluation::scale_factor(Value eg) const { Color strongSide = eg > VALUE_DRAW ? WHITE : BLACK; - ScaleFactor sf = me->scale_factor(pos, strongSide); + int sf = me->scale_factor(pos, strongSide); // If we don't already have an unusual scale factor, check for certain // types of endgames, and use a lower scale for those. @@ -803,27 +798,28 @@ namespace { // is almost a draw, in case of KBP vs KB, it is even more a draw. if ( pos.non_pawn_material(WHITE) == BishopValueMg && pos.non_pawn_material(BLACK) == BishopValueMg) - return more_than_one(pos.pieces(PAWN)) ? ScaleFactor(31) : ScaleFactor(9); + sf = more_than_one(pos.pieces(PAWN)) ? 31 : 9; // Endgame with opposite-colored bishops, but also other pieces. Still // a bit drawish, but not as drawish as with only the two bishops. - return ScaleFactor(46); + else + sf = 46; } - // Endings where weaker side can place his king in front of the opponent's + // Endings where weaker side can place his king in front of the enemy's // pawns are drawish. else if ( abs(eg) <= BishopValueEg && pos.count(strongSide) <= 2 && !pos.pawn_passed(~strongSide, pos.square(~strongSide))) - return ScaleFactor(37 + 7 * pos.count(strongSide)); + sf = 37 + 7 * pos.count(strongSide); } - return sf; + return ScaleFactor(sf); } - // value() is the main function of the class. It computes the various parts of - // the evaluation and returns the value of the position from the point of view - // of the side to move. + // Evaluation::value() is the main function of the class. It computes the various + // parts of the evaluation and returns the value of the position from the point + // of view of the side to move. template Value Evaluation::value() { @@ -845,7 +841,7 @@ namespace { // Probe the pawn hash table pe = Pawns::probe(pos); - score += pe->pawns_score(); + score += pe->pawn_score(WHITE) - pe->pawn_score(BLACK); // Early exit if score is high Value v = (mg_value(score) + eg_value(score)) / 2; @@ -857,30 +853,23 @@ namespace { initialize(); initialize(); - score += evaluate_pieces() - evaluate_pieces(); - score += evaluate_pieces() - evaluate_pieces(); - score += evaluate_pieces() - evaluate_pieces(); - score += evaluate_pieces() - evaluate_pieces(); + // Pieces should be evaluated first (populate attack tables) + score += pieces() - pieces() + + pieces() - pieces() + + pieces() - pieces() + + pieces() - pieces(); score += mobility[WHITE] - mobility[BLACK]; - score += evaluate_king() - - evaluate_king(); - - score += evaluate_threats() - - evaluate_threats(); + score += king< WHITE>() - king< BLACK>() + + threats() - threats() + + passed< WHITE>() - passed< BLACK>() + + space< WHITE>() - space< BLACK>(); - score += evaluate_passed_pawns() - - evaluate_passed_pawns(); - - if (pos.non_pawn_material() >= SpaceThreshold) - score += evaluate_space() - - evaluate_space(); - - score += evaluate_initiative(eg_value(score)); + score += initiative(eg_value(score)); // Interpolate between a middlegame and a (scaled by 'sf') endgame score - ScaleFactor sf = evaluate_scale_factor(eg_value(score)); + ScaleFactor sf = scale_factor(eg_value(score)); v = mg_value(score) * int(me->game_phase()) + eg_value(score) * int(PHASE_MIDGAME - me->game_phase()) * sf / SCALE_FACTOR_NORMAL; @@ -891,29 +880,26 @@ namespace { { Trace::add(MATERIAL, pos.psq_score()); Trace::add(IMBALANCE, me->imbalance()); - Trace::add(PAWN, pe->pawns_score()); + Trace::add(PAWN, pe->pawn_score(WHITE), pe->pawn_score(BLACK)); Trace::add(MOBILITY, mobility[WHITE], mobility[BLACK]); - if (pos.non_pawn_material() >= SpaceThreshold) - Trace::add(SPACE, evaluate_space() - , evaluate_space()); Trace::add(TOTAL, score); } - return pos.side_to_move() == WHITE ? v : -v; // Side to move point of view + return (pos.side_to_move() == WHITE ? v : -v) // Side to move point of view + + Eval::Tempo; } } // namespace -std::atomic Eval::Contempt; -/// evaluate() is the evaluator for the outer world. It returns a static evaluation -/// of the position from the point of view of the side to move. +/// evaluate() is the evaluator for the outer world. It returns a static +/// evaluation of the position from the point of view of the side to move. -Value Eval::evaluate(const Position& pos) -{ - return Evaluation<>(pos).value() + Eval::Tempo; +Value Eval::evaluate(const Position& pos) { + return Evaluation(pos).value(); } + /// trace() is like evaluate(), but instead of returning a value, it returns /// a string (suitable for outputting to stdout) that contains the detailed /// descriptions and values of each evaluation term. Useful for debugging. @@ -922,34 +908,34 @@ std::string Eval::trace(const Position& pos) { std::memset(scores, 0, sizeof(scores)); - Eval::Contempt = SCORE_ZERO; + Eval::Contempt = SCORE_ZERO; // Reset any dynamic contempt - Value v = Eval::Tempo + Evaluation(pos).value(); + Value v = Evaluation(pos).value(); - v = pos.side_to_move() == WHITE ? v : -v; // White's point of view + v = pos.side_to_move() == WHITE ? v : -v; // Trace scores are from white's point of view std::stringstream ss; ss << std::showpoint << std::noshowpos << std::fixed << std::setprecision(2) - << " Eval term | White | Black | Total \n" - << " | MG EG | MG EG | MG EG \n" - << "----------------+-------------+-------------+-------------\n" - << " Material | " << Term(MATERIAL) - << " Imbalance | " << Term(IMBALANCE) - << " Pawns | " << Term(PAWN) - << " Knights | " << Term(KNIGHT) - << " Bishops | " << Term(BISHOP) - << " Rooks | " << Term(ROOK) - << " Queens | " << Term(QUEEN) - << " Mobility | " << Term(MOBILITY) - << " King safety | " << Term(KING) - << " Threats | " << Term(THREAT) - << " Passed pawns | " << Term(PASSED) - << " Space | " << Term(SPACE) - << " Initiative | " << Term(INITIATIVE) - << "----------------+-------------+-------------+-------------\n" - << " Total | " << Term(TOTAL); - - ss << "\nTotal Evaluation: " << to_cp(v) << " (white side)\n"; + << " Term | White | Black | Total \n" + << " | MG EG | MG EG | MG EG \n" + << " ------------+-------------+-------------+------------\n" + << " Material | " << Term(MATERIAL) + << " Imbalance | " << Term(IMBALANCE) + << " Initiative | " << Term(INITIATIVE) + << " Pawns | " << Term(PAWN) + << " Knights | " << Term(KNIGHT) + << " Bishops | " << Term(BISHOP) + << " Rooks | " << Term(ROOK) + << " Queens | " << Term(QUEEN) + << " Mobility | " << Term(MOBILITY) + << " King safety | " << Term(KING) + << " Threats | " << Term(THREAT) + << " Passed | " << Term(PASSED) + << " Space | " << Term(SPACE) + << " ------------+-------------+-------------+------------\n" + << " Total | " << Term(TOTAL); + + ss << "\nTotal evaluation: " << to_cp(v) << " (white side)\n"; return ss.str(); }