X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fevaluate.cpp;h=a5c049a88adb8446cb14720a51b3ab109effa45d;hb=HEAD;hp=60ec9c72a5b1577ed0976230fcc74c28715aa861;hpb=ab5cd8340f2f7f8730aa7c77476edf4a98a166e4;p=stockfish diff --git a/src/evaluate.cpp b/src/evaluate.cpp index 60ec9c72..586cadc0 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -1,8 +1,6 @@ /* 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) 2004-2023 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 @@ -18,913 +16,218 @@ along with this program. If not, see . */ +#include "evaluate.h" + #include #include -#include // For std::memset +#include +#include +#include #include +#include #include +#include -#include "bitboard.h" -#include "evaluate.h" -#include "material.h" -#include "pawns.h" +#include "incbin/incbin.h" +#include "misc.h" +#include "nnue/evaluate_nnue.h" +#include "position.h" #include "thread.h" - -namespace Trace { - - enum Tracing { NO_TRACE, TRACE }; - - enum Term { // The first 8 entries are reserved for PieceType - MATERIAL = 8, IMBALANCE, MOBILITY, THREAT, PASSED, SPACE, WINNABLE, TOTAL, TERM_NB - }; - - Score scores[TERM_NB][COLOR_NB]; - - double to_cp(Value v) { return double(v) / PawnValueEg; } - - void add(int idx, Color c, Score s) { - scores[idx][c] = s; - } - - void add(int idx, Score w, Score b = SCORE_ZERO) { - scores[idx][WHITE] = w; - scores[idx][BLACK] = b; - } - - 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; - } - - std::ostream& operator<<(std::ostream& os, Term t) { - - if (t == MATERIAL || t == IMBALANCE || t == WINNABLE || t == TOTAL) - os << " ---- ----" << " | " << " ---- ----"; - else - os << scores[t][WHITE] << " | " << scores[t][BLACK]; - - os << " | " << scores[t][WHITE] - scores[t][BLACK] << "\n"; - return os; - } -} - -using namespace Trace; - -namespace { - - // Threshold for lazy and space evaluation - constexpr Value LazyThreshold = Value(1400); - constexpr Value SpaceThreshold = Value(12222); - - // KingAttackWeights[PieceType] contains king attack weights by piece type - constexpr int KingAttackWeights[PIECE_TYPE_NB] = { 0, 0, 81, 52, 44, 10 }; - - // Penalties for enemy's safe checks - constexpr int QueenSafeCheck = 772; - constexpr int RookSafeCheck = 1084; - constexpr int BishopSafeCheck = 645; - constexpr int KnightSafeCheck = 792; - -#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. - constexpr Score MobilityBonus[][32] = { - { S(-62,-81), S(-53,-56), S(-12,-31), S( -4,-16), S( 3, 5), S( 13, 11), // Knight - S( 22, 17), S( 28, 20), S( 33, 25) }, - { S(-48,-59), S(-20,-23), S( 16, -3), S( 26, 13), S( 38, 24), S( 51, 42), // Bishop - S( 55, 54), S( 63, 57), S( 63, 65), S( 68, 73), S( 81, 78), S( 81, 86), - S( 91, 88), S( 98, 97) }, - { S(-60,-78), S(-20,-17), S( 2, 23), S( 3, 39), S( 3, 70), S( 11, 99), // Rook - S( 22,103), S( 31,121), S( 40,134), S( 40,139), S( 41,158), S( 48,164), - S( 57,168), S( 57,169), S( 62,172) }, - { S(-30,-48), S(-12,-30), S( -8, -7), S( -9, 19), S( 20, 40), S( 23, 55), // Queen - S( 23, 59), S( 35, 75), S( 38, 78), S( 53, 96), S( 64, 96), S( 65,100), - S( 65,121), S( 66,127), S( 67,131), S( 67,133), S( 72,136), S( 72,141), - S( 77,147), S( 79,150), S( 93,151), S(108,168), S(108,168), S(108,171), - S(110,182), S(114,182), S(114,192), S(116,219) } - }; - - // 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, 29) }; - - // ThreatByMinor/ByRook[attacked PieceType] contains bonuses according to - // which piece type attacks which one. Attacks on lesser pieces which are - // pawn-defended are not considered. - constexpr Score ThreatByMinor[PIECE_TYPE_NB] = { - S(0, 0), S(5, 32), S(57, 41), S(77, 56), S(88, 119), S(79, 161) - }; - - constexpr Score ThreatByRook[PIECE_TYPE_NB] = { - S(0, 0), S(3, 46), S(37, 68), S(42, 60), S(0, 38), S(58, 41) - }; - - // PassedRank[Rank] contains a bonus according to the rank of a passed pawn - constexpr Score PassedRank[RANK_NB] = { - S(0, 0), S(10, 28), S(17, 33), S(15, 41), S(62, 72), S(168, 177), S(276, 260) - }; - - // Assorted bonuses and penalties - constexpr Score BishopKingProtector = S( 6, 9); - constexpr Score BishopOnKingRing = S( 24, 0); - constexpr Score BishopOutpost = S( 30, 23); - constexpr Score BishopPawns = S( 3, 7); - constexpr Score BishopXRayPawns = S( 4, 5); - constexpr Score CorneredBishop = S( 50, 50); - constexpr Score FlankAttacks = S( 8, 0); - constexpr Score Hanging = S( 69, 36); - constexpr Score KnightKingProtector = S( 8, 9); - constexpr Score KnightOnQueen = S( 16, 11); - constexpr Score KnightOutpost = S( 56, 36); - constexpr Score LongDiagonalBishop = S( 45, 0); - constexpr Score MinorBehindPawn = S( 18, 3); - constexpr Score PassedFile = S( 11, 8); - constexpr Score PawnlessFlank = S( 17, 95); - constexpr Score QueenInfiltration = S( -2, 14); - constexpr Score ReachableOutpost = S( 31, 22); - constexpr Score RestrictedPiece = S( 7, 7); - constexpr Score RookOnKingRing = S( 16, 0); - constexpr Score RookOnQueenFile = S( 6, 11); - constexpr Score SliderOnQueen = S( 60, 18); - constexpr Score ThreatByKing = S( 24, 89); - constexpr Score ThreatByPawnPush = S( 48, 39); - constexpr Score ThreatBySafePawn = S(173, 94); - constexpr Score TrappedRook = S( 55, 13); - constexpr Score WeakQueenProtection = S( 14, 0); - constexpr Score WeakQueen = S( 56, 15); - - -#undef S - - // Evaluation class computes and stores attacks tables and other working data - template - class Evaluation { - - public: - Evaluation() = delete; - explicit Evaluation(const Position& p) : pos(p) {} - Evaluation& operator=(const Evaluation&) = delete; - Value value(); - - private: - template void initialize(); - template Score pieces(); - template Score king() const; - template Score threats() const; - template Score passed() const; - template Score space() const; - Value winnable(Score score) const; - - 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 at least 2 units of a given - // color, including x-rays. But diagonal x-rays through pawns are not computed. - Bitboard attackedBy2[COLOR_NB]; - - // kingRing[color] are the squares adjacent to the king plus some other - // very near squares, depending on king position. - 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]; - }; - - - // 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() { - - constexpr Color Them = ~Us; - constexpr Direction Up = pawn_push(Us); - constexpr Direction Down = -Up; - constexpr Bitboard LowRanks = (Us == WHITE ? Rank2BB | Rank3BB : Rank7BB | Rank6BB); - - const Square ksq = pos.square(Us); - - Bitboard dblAttackByPawn = pawn_double_attacks_bb(pos.pieces(Us, PAWN)); - - // 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 queen, by blockers to attacks on our king - // or controlled by enemy pawns are excluded from the mobility area. - mobilityArea[Us] = ~(b | pos.pieces(Us, KING, QUEEN) | pos.blockers_for_king(Us) | pe->pawn_attacks(Them)); - - // Initialize attackedBy[] for king and pawns - attackedBy[Us][KING] = attacks_bb(ksq); - attackedBy[Us][PAWN] = pe->pawn_attacks(Us); - attackedBy[Us][ALL_PIECES] = attackedBy[Us][KING] | attackedBy[Us][PAWN]; - attackedBy2[Us] = dblAttackByPawn | (attackedBy[Us][KING] & attackedBy[Us][PAWN]); - - // Init our king safety tables - Square s = make_square(Utility::clamp(file_of(ksq), FILE_B, FILE_G), - Utility::clamp(rank_of(ksq), RANK_2, RANK_7)); - kingRing[Us] = attacks_bb(s) | s; - - kingAttackersCount[Them] = popcount(kingRing[Us] & pe->pawn_attacks(Them)); - kingAttacksCount[Them] = kingAttackersWeight[Them] = 0; - - // Remove from kingRing[] the squares defended by two pawns - kingRing[Us] &= ~dblAttackByPawn; - } - - - // Evaluation::pieces() scores pieces of a given color and type - - template template - Score Evaluation::pieces() { - - constexpr Color Them = ~Us; - constexpr Direction Down = -pawn_push(Us); - constexpr Bitboard OutpostRanks = (Us == WHITE ? Rank4BB | Rank5BB | Rank6BB - : Rank5BB | Rank4BB | Rank3BB); - const Square* pl = pos.squares(Us); - - Bitboard b, bb; - Score score = SCORE_ZERO; - - attackedBy[Us][Pt] = 0; - - for (Square s = *pl; s != SQ_NONE; s = *++pl) - { - // 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)) - : attacks_bb(s, pos.pieces()); - - if (pos.blockers_for_king(Us) & s) - b &= line_bb(pos.square(Us), s); - - attackedBy2[Us] |= attackedBy[Us][ALL_PIECES] & b; - attackedBy[Us][Pt] |= b; - attackedBy[Us][ALL_PIECES] |= b; - - if (b & kingRing[Them]) - { - kingAttackersCount[Us]++; - kingAttackersWeight[Us] += KingAttackWeights[Pt]; - kingAttacksCount[Us] += popcount(b & attackedBy[Them][KING]); - } - - else if (Pt == ROOK && (file_bb(s) & kingRing[Them])) - score += RookOnKingRing; - - else if (Pt == BISHOP && (attacks_bb(s, pos.pieces(PAWN)) & kingRing[Them])) - score += BishopOnKingRing; - - int mob = popcount(b & mobilityArea[Us]); - - mobility[Us] += MobilityBonus[Pt - 2][mob]; - - if (Pt == BISHOP || Pt == KNIGHT) +#include "types.h" +#include "uci.h" + +// Macro to embed the default efficiently updatable neural network (NNUE) file +// data in the engine binary (using incbin.h, by Dale Weiler). +// This macro invocation will declare the following three variables +// const unsigned char gEmbeddedNNUEData[]; // a pointer to the embedded data +// const unsigned char *const gEmbeddedNNUEEnd; // a marker to the end +// const unsigned int gEmbeddedNNUESize; // the size of the embedded file +// Note that this does not work in Microsoft Visual Studio. +#if !defined(_MSC_VER) && !defined(NNUE_EMBEDDING_OFF) +INCBIN(EmbeddedNNUE, EvalFileDefaultName); +#else +const unsigned char gEmbeddedNNUEData[1] = {0x0}; +const unsigned char* const gEmbeddedNNUEEnd = &gEmbeddedNNUEData[1]; +const unsigned int gEmbeddedNNUESize = 1; +#endif + + +namespace Stockfish { + +namespace Eval { + +std::string currentEvalFileName = "None"; + +// Tries to load a NNUE network at startup time, or when the engine +// receives a UCI command "setoption name EvalFile value nn-[a-z0-9]{12}.nnue" +// The name of the NNUE network is always retrieved from the EvalFile option. +// We search the given network in three locations: internally (the default +// network may be embedded in the binary), in the active working directory and +// in the engine directory. Distro packagers may define the DEFAULT_NNUE_DIRECTORY +// variable to have the engine search in a special directory in their distro. +void NNUE::init() { + + std::string eval_file = std::string(Options["EvalFile"]); + if (eval_file.empty()) + eval_file = EvalFileDefaultName; + +#if defined(DEFAULT_NNUE_DIRECTORY) + std::vector dirs = {"", "", CommandLine::binaryDirectory, + stringify(DEFAULT_NNUE_DIRECTORY)}; +#else + std::vector dirs = {"", "", CommandLine::binaryDirectory}; +#endif + + for (const std::string& directory : dirs) + if (currentEvalFileName != eval_file) { - // Bonus if piece is on an outpost square or can reach one - bb = OutpostRanks & attackedBy[Us][PAWN] & ~pe->pawn_attacks_span(Them); - if (bb & s) - score += (Pt == KNIGHT) ? KnightOutpost : BishopOutpost; - else if (Pt == KNIGHT && bb & b & ~pos.pieces(Us)) - score += ReachableOutpost; - - // Bonus for a knight or bishop shielded by pawn - if (shift(pos.pieces(PAWN)) & s) - score += MinorBehindPawn; - - // Penalty if the piece is far from the king - score -= (Pt == KNIGHT ? KnightKingProtector - : BishopKingProtector) * distance(pos.square(Us), s); - - if (Pt == BISHOP) + if (directory != "") { - // Penalty according to the number of our pawns on the same color square as the - // bishop, bigger when the center files are blocked with pawns and smaller - // when the bishop is outside the pawn chain. - Bitboard blocked = pos.pieces(Us, PAWN) & shift(pos.pieces()); - - score -= BishopPawns * pos.pawns_on_same_color_squares(Us, s) - * (!(attackedBy[Us][PAWN] & s) + popcount(blocked & CenterFiles)); - - // Penalty for all enemy pawns x-rayed - score -= BishopXRayPawns * popcount(attacks_bb(s) & pos.pieces(Them, PAWN)); - - // Bonus for bishop on a long diagonal which can "see" both center squares - if (more_than_one(attacks_bb(s, pos.pieces(PAWN)) & Center)) - score += LongDiagonalBishop; - - // An important Chess960 pattern: a cornered bishop blocked by a friendly - // pawn diagonally in front of it is a very serious problem, especially - // when that pawn is also blocked. - if ( pos.is_chess960() - && (s == relative_square(Us, SQ_A1) || s == relative_square(Us, SQ_H1))) - { - 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)) ? CorneredBishop * 4 - : pos.piece_on(s + d + d) == make_piece(Us, PAWN) ? CorneredBishop * 2 - : CorneredBishop; - } + std::ifstream stream(directory + eval_file, std::ios::binary); + if (NNUE::load_eval(eval_file, stream)) + currentEvalFileName = eval_file; } - } - - if (Pt == ROOK) - { - // Bonus for rook on the same file as a queen - if (file_bb(s) & pos.pieces(QUEEN)) - score += RookOnQueenFile; - // Bonus for rook on an open or semi-open 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) + if (directory == "" && eval_file == EvalFileDefaultName) { - File kf = file_of(pos.square(Us)); - if ((kf < FILE_E) == (file_of(s) < kf)) - score -= TrappedRook * (1 + !pos.castling_rights(Us)); + // C++ way to prepare a buffer for a memory stream + class MemoryBuffer: public std::basic_streambuf { + public: + MemoryBuffer(char* p, size_t n) { + setg(p, p, p + n); + setp(p, p + n); + } + }; + + MemoryBuffer buffer( + const_cast(reinterpret_cast(gEmbeddedNNUEData)), + size_t(gEmbeddedNNUESize)); + (void) gEmbeddedNNUEEnd; // Silence warning on unused variable + + std::istream stream(&buffer); + if (NNUE::load_eval(eval_file, stream)) + currentEvalFileName = eval_file; } } +} - if (Pt == QUEEN) - { - // Penalty if any relative pin or discovered attack against the queen - Bitboard queenPinners; - if (pos.slider_blockers(pos.pieces(Them, ROOK, BISHOP), s, queenPinners)) - score -= WeakQueen; - - // Bonus for queen on weak square in enemy camp - if (relative_rank(Us, s) > RANK_4 && (~pe->pawn_attacks_span(Them) & s)) - score += QueenInfiltration; - } - } - if (T) - Trace::add(Pt, Us, score); - - return score; - } - - - // Evaluation::king() assigns bonuses and penalties to a king of a given color - - template template - Score Evaluation::king() const { - - constexpr Color Them = ~Us; - constexpr Bitboard Camp = (Us == WHITE ? AllSquares ^ Rank6BB ^ Rank7BB ^ Rank8BB - : AllSquares ^ Rank1BB ^ Rank2BB ^ Rank3BB); - - Bitboard weak, b1, b2, b3, safe, unsafeChecks = 0; - Bitboard rookChecks, queenChecks, bishopChecks, knightChecks; - int kingDanger = 0; - const Square ksq = pos.square(Us); - - // Init the score with king shelter and enemy pawns storm - Score score = pe->king_safety(pos); - - // Attacked squares defended at most once by our queen or king - weak = attackedBy[Them][ALL_PIECES] - & ~attackedBy2[Us] - & (~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); - safe &= ~attackedBy[Us][ALL_PIECES] | (weak & attackedBy2[Them]); - - b1 = attacks_bb(ksq, pos.pieces() ^ pos.pieces(Us, QUEEN)); - b2 = attacks_bb(ksq, pos.pieces() ^ pos.pieces(Us, QUEEN)); - - // Enemy rooks checks - rookChecks = b1 & safe & attackedBy[Them][ROOK]; - if (rookChecks) - kingDanger += more_than_one(rookChecks) ? RookSafeCheck * 175/100 - : RookSafeCheck; - else - unsafeChecks |= b1 & attackedBy[Them][ROOK]; - - // Enemy queen safe checks: we count them only if they are from squares from - // which we can't give a rook check, because rook checks are more valuable. - queenChecks = (b1 | b2) - & attackedBy[Them][QUEEN] - & safe - & ~attackedBy[Us][QUEEN] - & ~rookChecks; - if (queenChecks) - kingDanger += more_than_one(queenChecks) ? QueenSafeCheck * 145/100 - : QueenSafeCheck; - - // Enemy bishops checks: we count them only if they are from squares from - // which we can't give a queen check, because queen checks are more valuable. - bishopChecks = b2 - & attackedBy[Them][BISHOP] - & safe - & ~queenChecks; - if (bishopChecks) - kingDanger += more_than_one(bishopChecks) ? BishopSafeCheck * 3/2 - : BishopSafeCheck; - else - unsafeChecks |= b2 & attackedBy[Them][BISHOP]; - - // Enemy knights checks - knightChecks = attacks_bb(ksq) & attackedBy[Them][KNIGHT]; - if (knightChecks & safe) - kingDanger += more_than_one(knightChecks & safe) ? KnightSafeCheck * 162/100 - : KnightSafeCheck; - else - unsafeChecks |= knightChecks; - - // Find the squares that opponent attacks in our king flank, the squares - // which they attack twice in that flank, and the squares that we defend. - b1 = attackedBy[Them][ALL_PIECES] & KingFlank[file_of(ksq)] & Camp; - b2 = b1 & attackedBy2[Them]; - b3 = attackedBy[Us][ALL_PIECES] & KingFlank[file_of(ksq)] & Camp; - - int kingFlankAttack = popcount(b1) + popcount(b2); - int kingFlankDefense = popcount(b3); - - kingDanger += kingAttackersCount[Them] * kingAttackersWeight[Them] - + 185 * popcount(kingRing[Us] & weak) - + 148 * popcount(unsafeChecks) - + 98 * popcount(pos.blockers_for_king(Us)) - + 69 * kingAttacksCount[Them] - + 3 * kingFlankAttack * kingFlankAttack / 8 - + mg_value(mobility[Them] - mobility[Us]) - - 873 * !pos.count(Them) - - 100 * bool(attackedBy[Us][KNIGHT] & attackedBy[Us][KING]) - - 6 * mg_value(score) / 8 - - 4 * kingFlankDefense - + 37; - - // Transform the kingDanger units into a Score, and subtract it from the evaluation - if (kingDanger > 100) - score -= make_score(kingDanger * kingDanger / 4096, kingDanger / 16); - - // Penalty when our king is on a pawnless flank - if (!(pos.pieces(PAWN) & KingFlank[file_of(ksq)])) - score -= PawnlessFlank; - - // Penalty if king flank is under attack, potentially moving toward the king - score -= FlankAttacks * kingFlankAttack; - - if (T) - Trace::add(KING, Us, score); - - return score; - } - - - // Evaluation::threats() assigns bonuses according to the types of the - // attacking and the attacked pieces. - - template template - Score Evaluation::threats() const { - - constexpr Color Them = ~Us; - constexpr Direction Up = pawn_push(Us); - constexpr Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB); - - Bitboard b, weak, defended, nonPawnEnemies, stronglyProtected, safe; - Score score = SCORE_ZERO; - - // Non-pawn enemies - nonPawnEnemies = pos.pieces(Them) & ~pos.pieces(PAWN); - - // 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 = nonPawnEnemies & stronglyProtected; - - // Enemies not strongly protected and under our attack - weak = pos.pieces(Them) & ~stronglyProtected & attackedBy[Us][ALL_PIECES]; - - // Bonus according to the kind of attacking pieces - if (defended | weak) - { - b = (defended | weak) & (attackedBy[Us][KNIGHT] | attackedBy[Us][BISHOP]); - while (b) - score += ThreatByMinor[type_of(pos.piece_on(pop_lsb(&b)))]; - - b = weak & attackedBy[Us][ROOK]; - while (b) - score += ThreatByRook[type_of(pos.piece_on(pop_lsb(&b)))]; - - if (weak & attackedBy[Us][KING]) - score += ThreatByKing; - - b = ~attackedBy[Them][ALL_PIECES] - | (nonPawnEnemies & attackedBy2[Us]); - score += Hanging * popcount(weak & b); - - // Additional bonus if weak piece is only protected by a queen - score += WeakQueenProtection * popcount(weak & attackedBy[Them][QUEEN]); - } - - // Bonus for restricting their piece moves - b = attackedBy[Them][ALL_PIECES] - & ~stronglyProtected - & attackedBy[Us][ALL_PIECES]; - score += RestrictedPiece * popcount(b); - - // Protected or unattacked squares - safe = ~attackedBy[Them][ALL_PIECES] | attackedBy[Us][ALL_PIECES]; - - // Bonus for attacking enemy pieces with our relatively safe pawns - b = pos.pieces(Us, PAWN) & safe; - b = pawn_attacks_bb(b) & nonPawnEnemies; - score += ThreatBySafePawn * popcount(b); - - // Find squares where our pawns can push on the next move - b = shift(pos.pieces(Us, PAWN)) & ~pos.pieces(); - b |= shift(b & TRank3BB) & ~pos.pieces(); - - // Keep only the squares which are relatively safe - b &= ~attackedBy[Them][PAWN] & safe; - - // Bonus for safe pawn threats on the next move - b = pawn_attacks_bb(b) & nonPawnEnemies; - score += ThreatByPawnPush * popcount(b); - - // Bonus for threats on the next moves against enemy queen - if (pos.count(Them) == 1) - { - Square s = pos.square(Them); - safe = mobilityArea[Us] & ~stronglyProtected; - - b = attackedBy[Us][KNIGHT] & attacks_bb(s); - - score += KnightOnQueen * popcount(b & safe); - - b = (attackedBy[Us][BISHOP] & attacks_bb(s, pos.pieces())) - | (attackedBy[Us][ROOK ] & attacks_bb(s, pos.pieces())); - - score += SliderOnQueen * popcount(b & safe & attackedBy2[Us]); - } - - if (T) - Trace::add(THREAT, Us, score); - - return score; - } - - // Evaluation::passed() evaluates the passed pawns and candidate passed - // pawns of the given color. - - template template - Score Evaluation::passed() const { - - constexpr Color Them = ~Us; - constexpr Direction Up = pawn_push(Us); - constexpr Direction Down = -Up; - - auto king_proximity = [&](Color c, Square s) { - return std::min(distance(pos.square(c), s), 5); - }; - - Bitboard b, bb, squaresToQueen, unsafeSquares, blockedPassers, helpers; - Score score = SCORE_ZERO; - - b = pe->passed_pawns(Us); +// Verifies that the last net used was loaded successfully +void NNUE::verify() { - blockedPassers = b & shift(pos.pieces(Them, PAWN)); - if (blockedPassers) - { - helpers = shift(pos.pieces(Us, PAWN)) - & ~pos.pieces(Them) - & (~attackedBy2[Them] | attackedBy[Us][ALL_PIECES]); - - // Remove blocked candidate passers that don't have help to pass - b &= ~blockedPassers - | shift(helpers) - | shift(helpers); - } + std::string eval_file = std::string(Options["EvalFile"]); + if (eval_file.empty()) + eval_file = EvalFileDefaultName; - while (b) + if (currentEvalFileName != eval_file) { - Square s = pop_lsb(&b); - - assert(!(pos.pieces(Them, PAWN) & forward_file_bb(Us, s + Up))); - - int r = relative_rank(Us, s); - - Score bonus = PassedRank[r]; - - if (r > RANK_3) - { - int w = 5 * r - 13; - Square blockSq = s + Up; - - // Adjust bonus based on the king's proximity - bonus += make_score(0, ( (king_proximity(Them, blockSq) * 19) / 4 - - king_proximity(Us, blockSq) * 2) * w); - // If blockSq is not the queening square then consider also a second push - if (r != RANK_7) - 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)) - { - squaresToQueen = forward_file_bb(Us, s); - unsafeSquares = passed_pawn_span(Us, s); - - bb = forward_file_bb(Them, s) & pos.pieces(ROOK, QUEEN); - - if (!(pos.pieces(Them) & bb)) - unsafeSquares &= attackedBy[Them][ALL_PIECES]; - - // If there are no enemy attacks on passed pawn span, assign a big bonus. - // Otherwise assign a smaller bonus if the path to queen is not attacked - // and even smaller bonus if it is attacked but block square is not. - int k = !unsafeSquares ? 35 : - !(unsafeSquares & squaresToQueen) ? 20 : - !(unsafeSquares & blockSq) ? 9 : - 0 ; - - // Assign a larger bonus if the block square is defended - if ((pos.pieces(Us) & bb) || (attackedBy[Us][ALL_PIECES] & blockSq)) - k += 5; - - bonus += make_score(k * w, k * w); - } - } // r > RANK_3 - - score += bonus - PassedFile * edge_distance(file_of(s)); + std::string msg1 = + "Network evaluation parameters compatible with the engine must be available."; + std::string msg2 = "The network file " + eval_file + " was not loaded successfully."; + std::string msg3 = "The UCI option EvalFile might need to specify the full path, " + "including the directory name, to the network file."; + std::string msg4 = "The default net can be downloaded from: " + "https://tests.stockfishchess.org/api/nn/" + + std::string(EvalFileDefaultName); + std::string msg5 = "The engine will be terminated now."; + + sync_cout << "info string ERROR: " << msg1 << sync_endl; + sync_cout << "info string ERROR: " << msg2 << sync_endl; + sync_cout << "info string ERROR: " << msg3 << sync_endl; + sync_cout << "info string ERROR: " << msg4 << sync_endl; + sync_cout << "info string ERROR: " << msg5 << sync_endl; + + exit(EXIT_FAILURE); } - if (T) - Trace::add(PASSED, Us, score); - - return score; - } - - - // Evaluation::space() computes a space evaluation for a given side, aiming to improve game - // play in the opening. It is based on the number of safe squares on the 4 central files - // on ranks 2 to 4. Completely safe squares behind a friendly pawn are counted twice. - // Finally, the space bonus is multiplied by a weight which decreases according to occupancy. - - template template - Score Evaluation::space() const { - - // Early exit if, for example, both queens or 6 minor pieces have been exchanged - if (pos.non_pawn_material() < SpaceThreshold) - return SCORE_ZERO; - - constexpr Color Them = ~Us; - constexpr Direction Down = -pawn_push(Us); - constexpr Bitboard SpaceMask = - Us == WHITE ? CenterFiles & (Rank2BB | Rank3BB | Rank4BB) - : CenterFiles & (Rank7BB | Rank6BB | Rank5BB); - - // Find the available squares for our pieces inside the area defined by SpaceMask - Bitboard safe = SpaceMask - & ~pos.pieces(Us, PAWN) - & ~attackedBy[Them][PAWN]; - - // Find all squares which are at most three squares behind some friendly pawn - Bitboard behind = pos.pieces(Us, PAWN); - behind |= shift(behind); - behind |= shift(behind); - - 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); - - if (T) - Trace::add(SPACE, Us, score); - - return score; - } - - - // Evaluation::winnable() adjusts the mg and eg score components based on the - // known attacking/defending status of the players. A single value is derived - // by interpolation from the mg and eg values and returned. - - template - Value Evaluation::winnable(Score score) const { - - int outflanking = distance(pos.square(WHITE), pos.square(BLACK)) - - distance(pos.square(WHITE), pos.square(BLACK)); - - bool pawnsOnBothFlanks = (pos.pieces(PAWN) & QueenSide) - && (pos.pieces(PAWN) & KingSide); - - bool almostUnwinnable = outflanking < 0 - && !pawnsOnBothFlanks; - - bool infiltration = rank_of(pos.square(WHITE)) > RANK_4 - || rank_of(pos.square(BLACK)) < RANK_5; - - // Compute the initiative bonus for the attacking side - int complexity = 9 * pe->passed_count() - + 12 * pos.count() - + 9 * outflanking - + 21 * pawnsOnBothFlanks - + 24 * infiltration - + 51 * !pos.non_pawn_material() - - 43 * almostUnwinnable - -110 ; - - Value mg = mg_value(score); - Value eg = eg_value(score); - - // Now apply the bonus: note that we find the attacking side by extracting the - // sign of the midgame or endgame values, and that we carefully cap the bonus - // so that the midgame and endgame scores do not change sign after the bonus. - int u = ((mg > 0) - (mg < 0)) * Utility::clamp(complexity + 50, -abs(mg), 0); - int v = ((eg > 0) - (eg < 0)) * std::max(complexity, -abs(eg)); - - mg += u; - eg += v; - - // Compute the scale factor for the winning side - - Color strongSide = eg > VALUE_DRAW ? WHITE : BLACK; - int sf = me->scale_factor(pos, strongSide); - - // If scale is not already specific, scale down the endgame via general heuristics - if (sf == SCALE_FACTOR_NORMAL) - { - if (pos.opposite_bishops()) - { - if ( pos.non_pawn_material(WHITE) == BishopValueMg - && pos.non_pawn_material(BLACK) == BishopValueMg) - sf = 18 + 4 * popcount(pe->passed_pawns(strongSide)); - else - sf = 22 + 3 * pos.count(strongSide); - } - else - sf = std::min(sf, 36 + 7 * pos.count(strongSide)); - } - - // Interpolate between the middlegame and (scaled by 'sf') endgame score - v = mg * int(me->game_phase()) - + eg * int(PHASE_MIDGAME - me->game_phase()) * ScaleFactor(sf) / SCALE_FACTOR_NORMAL; - v /= PHASE_MIDGAME; - - if (T) - { - Trace::add(WINNABLE, make_score(u, eg * ScaleFactor(sf) / SCALE_FACTOR_NORMAL - eg_value(score))); - Trace::add(TOTAL, make_score(mg, eg * ScaleFactor(sf) / SCALE_FACTOR_NORMAL)); - } + sync_cout << "info string NNUE evaluation using " << eval_file << sync_endl; +} +} - return Value(v); - } +// Returns a static, purely materialistic evaluation of the position from +// the point of view of the given color. It can be divided by PawnValue to get +// an approximation of the material advantage on the board in terms of pawns. +Value Eval::simple_eval(const Position& pos, Color c) { + return PawnValue * (pos.count(c) - pos.count(~c)) + + (pos.non_pawn_material(c) - pos.non_pawn_material(~c)); +} - // 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() { +// 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) { assert(!pos.checkers()); - // Probe the material hash table - me = Material::probe(pos); - - // If we have a specialized evaluation function for the current material - // configuration, call it and return. - if (me->specialized_eval_exists()) - return me->evaluate(pos); - - // Initialize score by reading the incrementally updated scores included in - // the position object (material + piece square tables) and the material - // imbalance. Score is computed internally from the white point of view. - Score score = pos.psq_score() + me->imbalance() + pos.this_thread()->contempt; - - // Probe the pawn hash table - pe = Pawns::probe(pos); - score += pe->pawn_score(WHITE) - pe->pawn_score(BLACK); - - // Early exit if score is high - Value v = (mg_value(score) + eg_value(score)) / 2; - if (abs(v) > LazyThreshold + pos.non_pawn_material() / 64) - return pos.side_to_move() == WHITE ? v : -v; + Value v; + Color stm = pos.side_to_move(); + int shuffling = pos.rule50_count(); + int simpleEval = simple_eval(pos, stm) + (int(pos.key() & 7) - 3); - // Main evaluation begins here - initialize(); - initialize(); + bool lazy = std::abs(simpleEval) >= RookValue + KnightValue + 16 * shuffling * shuffling + + std::abs(pos.this_thread()->bestValue) + + std::abs(pos.this_thread()->rootSimpleEval); - // Pieces evaluated first (also populates attackedBy, attackedBy2). - // Note that the order of evaluation of the terms is left unspecified. - score += pieces() - pieces() - + pieces() - pieces() - + pieces() - pieces() - + pieces() - pieces(); - - score += mobility[WHITE] - mobility[BLACK]; + if (lazy) + v = Value(simpleEval); + else + { + int nnueComplexity; + Value nnue = NNUE::evaluate(pos, true, &nnueComplexity); - // More complex interactions that require fully populated attack bitboards - score += king< WHITE>() - king< BLACK>() - + threats() - threats() - + passed< WHITE>() - passed< BLACK>() - + space< WHITE>() - space< BLACK>(); + Value optimism = pos.this_thread()->optimism[stm]; - // Derive single value from mg and eg parts of score - v = winnable(score); + // Blend optimism and eval with nnue complexity and material imbalance + optimism += optimism * (nnueComplexity + std::abs(simpleEval - nnue)) / 512; + nnue -= nnue * (nnueComplexity + std::abs(simpleEval - nnue)) / 32768; - // In case of tracing add all remaining individual evaluation terms - if (T) - { - Trace::add(MATERIAL, pos.psq_score()); - Trace::add(IMBALANCE, me->imbalance()); - Trace::add(PAWN, pe->pawn_score(WHITE), pe->pawn_score(BLACK)); - Trace::add(MOBILITY, mobility[WHITE], mobility[BLACK]); + int npm = pos.non_pawn_material() / 64; + v = (nnue * (915 + npm + 9 * pos.count()) + optimism * (154 + npm)) / 1024; } - // Evaluation grain - v = (v / 16) * 16; - - // Side to move point of view - v = (pos.side_to_move() == WHITE ? v : -v) + Tempo; - // Damp down the evaluation linearly when shuffling - v = v * (100 - pos.rule50_count()) / 100; - - return v; - } + v = v * (200 - shuffling) / 214; -} // namespace + // Guarantee evaluation does not hit the tablebase range + v = std::clamp(v, VALUE_TB_LOSS_IN_MAX_PLY + 1, VALUE_TB_WIN_IN_MAX_PLY - 1); - -/// 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(); + return v; } +// 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. +// Trace scores are from white's point of view +std::string Eval::trace(Position& pos) { -/// 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. - -std::string Eval::trace(const Position& pos) { - - if (pos.checkers()) - return "Total evaluation: none (in check)"; + if (pos.checkers()) + return "Final evaluation: none (in check)"; - std::memset(scores, 0, sizeof(scores)); + // Reset any global variable used in eval + pos.this_thread()->bestValue = VALUE_ZERO; + pos.this_thread()->rootSimpleEval = VALUE_ZERO; + pos.this_thread()->optimism[WHITE] = VALUE_ZERO; + pos.this_thread()->optimism[BLACK] = VALUE_ZERO; - pos.this_thread()->contempt = SCORE_ZERO; // Reset any dynamic contempt + std::stringstream ss; + ss << std::showpoint << std::noshowpos << std::fixed << std::setprecision(2); + ss << '\n' << NNUE::trace(pos) << '\n'; - Value v = Evaluation(pos).value(); + ss << std::showpoint << std::showpos << std::fixed << std::setprecision(2) << std::setw(15); - v = pos.side_to_move() == WHITE ? v : -v; // Trace scores are from white's point of view + Value v; + v = NNUE::evaluate(pos, false); + v = pos.side_to_move() == WHITE ? v : -v; + ss << "NNUE evaluation " << 0.01 * UCI::to_cp(v) << " (white side)\n"; - std::stringstream ss; - ss << std::showpoint << std::noshowpos << std::fixed << std::setprecision(2) - << " 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 | " << Term(PASSED) - << " Space | " << Term(SPACE) - << " Winnable | " << Term(WINNABLE) - << " ------------+-------------+-------------+------------\n" - << " Total | " << Term(TOTAL); + v = evaluate(pos); + v = pos.side_to_move() == WHITE ? v : -v; + ss << "Final evaluation " << 0.01 * UCI::to_cp(v) << " (white side)"; + ss << " [with scaled NNUE, ...]"; + ss << "\n"; - ss << "\nFinal evaluation: " << to_cp(v) << " (white side)\n"; - - return ss.str(); + return ss.str(); } + +} // namespace Stockfish