X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fevaluate.cpp;h=fd51ad5347ae40161176b8ad6b684eb52c878a03;hp=a1a3b4ed267c6293f135e9fdef1b2c5beea3a82d;hb=d6d6972a66cb2fb599748bae1f14d32e6c42fc1e;hpb=0ae00454ba6928d181b46103e5c83e6d58fcebe5 diff --git a/src/evaluate.cpp b/src/evaluate.cpp index a1a3b4ed..fd51ad53 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) 2004-2020 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 @@ -20,22 +18,137 @@ #include #include +#include #include // For std::memset +#include #include #include +#include +#include +#include #include "bitboard.h" #include "evaluate.h" #include "material.h" +#include "misc.h" #include "pawns.h" #include "thread.h" +#include "uci.h" +#include "incbin/incbin.h" + + +// Macro to embed the default 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 Microsof 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 + + +using namespace std; +using namespace Eval::NNUE; + +namespace Eval { + + bool useNNUE; + string eval_file_loaded = "None"; + + /// NNUE::init() 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() { + + useNNUE = Options["Use NNUE"]; + if (!useNNUE) + return; + + string eval_file = string(Options["EvalFile"]); + + #if defined(DEFAULT_NNUE_DIRECTORY) + #define stringify2(x) #x + #define stringify(x) stringify2(x) + vector dirs = { "" , "" , CommandLine::binaryDirectory , stringify(DEFAULT_NNUE_DIRECTORY) }; + #else + vector dirs = { "" , "" , CommandLine::binaryDirectory }; + #endif + + for (string directory : dirs) + if (eval_file_loaded != eval_file) + { + if (directory != "") + { + ifstream stream(directory + eval_file, ios::binary); + if (load_eval(eval_file, stream)) + eval_file_loaded = eval_file; + } + + if (directory == "" && eval_file == EvalFileDefaultName) + { + // C++ way to prepare a buffer for a memory stream + class MemoryBuffer : public 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)); + + istream stream(&buffer); + if (load_eval(eval_file, stream)) + eval_file_loaded = eval_file; + } + } + } + + /// NNUE::verify() verifies that the last net used was loaded successfully + void NNUE::verify() { + + string eval_file = string(Options["EvalFile"]); + + if (useNNUE && eval_file_loaded != eval_file) + { + UCI::OptionsMap defaults; + UCI::init(defaults); + + string msg1 = "If the UCI option \"Use NNUE\" is set to true, network evaluation parameters compatible with the engine must be available."; + string msg2 = "The option is set to true, but the network file " + eval_file + " was not loaded successfully."; + string msg3 = "The UCI option EvalFile might need to specify the full path, including the directory name, to the network file."; + string msg4 = "The default net can be downloaded from: https://tests.stockfishchess.org/api/nn/" + string(defaults["EvalFile"]); + 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 (useNNUE) + sync_cout << "info string NNUE evaluation using " << eval_file << " enabled" << sync_endl; + else + sync_cout << "info string classical evaluation enabled" << sync_endl; + } +} namespace Trace { enum Tracing { NO_TRACE, TRACE }; enum Term { // The first 8 entries are reserved for PieceType - MATERIAL = 8, IMBALANCE, MOBILITY, THREAT, PASSED, SPACE, INITIATIVE, TOTAL, TERM_NB + MATERIAL = 8, IMBALANCE, MOBILITY, THREAT, PASSED, SPACE, WINNABLE, TOTAL, TERM_NB }; Score scores[TERM_NB][COLOR_NB]; @@ -59,7 +172,7 @@ namespace Trace { std::ostream& operator<<(std::ostream& os, Term t) { - if (t == MATERIAL || t == IMBALANCE || t == INITIATIVE || t == TOTAL) + if (t == MATERIAL || t == IMBALANCE || t == WINNABLE || t == TOTAL) os << " ---- ----" << " | " << " ---- ----"; else os << scores[t][WHITE] << " | " << scores[t][BLACK]; @@ -74,79 +187,96 @@ using namespace Trace; namespace { // Threshold for lazy and space evaluation - constexpr Value LazyThreshold = Value(1400); - constexpr Value SpaceThreshold = Value(12222); + 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 }; - // Penalties for enemy's safe checks - constexpr int QueenSafeCheck = 780; - constexpr int RookSafeCheck = 1080; - constexpr int BishopSafeCheck = 635; - constexpr int KnightSafeCheck = 790; + // SafeCheck[PieceType][single/multiple] contains safe check bonus by piece type, + // higher if multiple safe checks are possible for that piece type. + constexpr int SafeCheck[][2] = { + {}, {}, {803, 1292}, {639, 974}, {1087, 1878}, {759, 1132} + }; #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,-30), S( -4,-14), S( 3, 8), S( 13, 15), // Knights - S( 22, 23), S( 28, 27), S( 33, 33) }, - { S(-48,-59), S(-20,-23), S( 16, -3), S( 26, 13), S( 38, 24), S( 51, 42), // Bishops - 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(-58,-76), S(-27,-18), S(-15, 28), S(-10, 55), S( -5, 69), S( -2, 82), // Rooks - S( 9,112), S( 16,118), S( 30,132), S( 29,142), S( 32,155), S( 38,165), - S( 46,166), S( 48,169), S( 58,171) }, - { S(-39,-36), S(-21,-15), S( 3, 8), S( 3, 18), S( 14, 34), S( 22, 54), // Queens - S( 28, 61), S( 41, 73), S( 43, 79), S( 48, 92), S( 56, 94), S( 60,104), - S( 60,113), S( 66,120), S( 67,123), S( 70,126), S( 71,133), S( 73,136), - S( 79,140), S( 88,143), S( 88,148), S( 99,166), S(102,170), S(102,175), - S(106,184), S(109,191), S(113,206), S(116,212) } + { S(-62,-79), S(-53,-57), S(-12,-31), S( -3,-17), S( 3, 7), S( 12, 13), // Knight + S( 21, 16), S( 28, 21), S( 37, 26) }, + { S(-47,-59), S(-20,-25), S( 14, -8), S( 29, 12), S( 39, 21), S( 53, 40), // Bishop + S( 53, 56), S( 60, 58), S( 62, 65), S( 69, 72), S( 78, 78), S( 83, 87), + S( 91, 88), S( 96, 98) }, + { S(-60,-82), S(-24,-15), S( 0, 17) ,S( 3, 43), S( 4, 72), S( 14,100), // Rook + S( 20,102), S( 30,122), S( 41,133), S(41 ,139), S( 41,153), S( 45,160), + S( 57,165), S( 58,170), S( 67,175) }, + { S(-29,-49), S(-16,-29), S( -8, -8), S( -8, 17), S( 18, 39), S( 25, 54), // Queen + S( 23, 59), S( 37, 73), S( 41, 76), S( 54, 95), S( 65, 95) ,S( 68,101), + S( 69,124), S( 70,128), S( 70,132), S( 70,133) ,S( 71,136), S( 72,140), + S( 74,147), S( 76,149), S( 90,153), S(104,169), S(105,171), S(106,171), + S(112,178), S(114,185), S(114,187), S(119,221) } + }; + + // BishopPawns[distance from edge] contains a file-dependent penalty for pawns on + // squares of the same color as our bishop. + constexpr Score BishopPawns[int(FILE_NB) / 2] = { + S(3, 8), S(3, 9), S(1, 8), S(3, 7) + }; + + // KingProtector[knight/bishop] contains penalty for each distance unit to own king + constexpr Score KingProtector[] = { S(8, 9), S(6, 9) }; + + // Outpost[knight/bishop] contains bonuses for each knight or bishop occupying a + // pawn protected square on rank 4 to 6 which is also safe from a pawn attack. + constexpr Score Outpost[] = { S(56, 34), S(31, 23) }; + + // PassedRank[Rank] contains a bonus according to the rank of a passed pawn + constexpr Score PassedRank[RANK_NB] = { + 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(21, 4), S(47, 25) }; + 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 // pawn-defended are not considered. constexpr Score ThreatByMinor[PIECE_TYPE_NB] = { - S(0, 0), S(6, 32), S(59, 41), S(79, 56), S(90, 119), S(79, 161) + S(0, 0), S(5, 32), S(55, 41), S(77, 56), S(89, 119), S(79, 162) }; constexpr Score ThreatByRook[PIECE_TYPE_NB] = { - S(0, 0), S(3, 44), S(38, 71), S(38, 61), S(0, 38), S(51, 38) - }; - - // 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) + S(0, 0), S(3, 44), S(37, 68), S(42, 60), S(0, 39), S(58, 43) }; // Assorted bonuses and penalties - constexpr Score BishopPawns = S( 3, 7); - constexpr Score CorneredBishop = S( 50, 50); - constexpr Score FlankAttacks = S( 8, 0); - constexpr Score Hanging = S( 69, 36); - constexpr Score KingProtector = S( 7, 8); - constexpr Score KnightOnQueen = S( 16, 12); - constexpr Score LongDiagonalBishop = S( 45, 0); - constexpr Score MinorBehindPawn = S( 18, 3); - constexpr Score Outpost = S( 30, 21); - constexpr Score PassedFile = S( 11, 8); - constexpr Score PawnlessFlank = S( 17, 95); - constexpr Score RestrictedPiece = S( 7, 7); - constexpr Score ReachableOutpost = S( 32, 10); - constexpr Score RookOnQueenFile = S( 7, 6); - constexpr Score SliderOnQueen = S( 59, 18); - constexpr Score ThreatByKing = S( 24, 89); - constexpr Score ThreatByPawnPush = S( 48, 39); - constexpr Score ThreatBySafePawn = S(173, 94); - constexpr Score TrappedRook = S( 52, 30); - constexpr Score WeakQueen = S( 49, 15); + constexpr Score BadOutpost = S( -7, 36); + constexpr Score BishopOnKingRing = S( 24, 0); + 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 KnightOnQueen = S( 16, 11); + 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 ReachableOutpost = S( 31, 22); + constexpr Score RestrictedPiece = S( 7, 7); + constexpr Score RookOnKingRing = S( 16, 0); + 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 @@ -167,8 +297,7 @@ namespace { template Score threats() const; template Score passed() const; template Score space() const; - ScaleFactor scale_factor(Value eg) const; - Score initiative(Score score) const; + Value winnable(Score score) const; const Position& pos; Material::Entry* me; @@ -210,10 +339,11 @@ namespace { // 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 == WHITE ? BLACK : WHITE); + constexpr Color Them = ~Us; constexpr Direction Up = pawn_push(Us); constexpr Direction Down = -Up; constexpr Bitboard LowRanks = (Us == WHITE ? Rank2BB | Rank3BB : Rank7BB | Rank6BB); @@ -230,15 +360,15 @@ namespace { 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] = pos.attacks_from(ksq); + 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(clamp(file_of(ksq), FILE_B, FILE_G), - clamp(rank_of(ksq), RANK_2, RANK_7)); - kingRing[Us] = PseudoAttacks[KING][s] | s; + Square s = make_square(std::clamp(file_of(ksq), FILE_B, FILE_G), + std::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; @@ -249,10 +379,11 @@ namespace { // Evaluation::pieces() scores pieces of a given color and type + template template Score Evaluation::pieces() { - constexpr Color Them = (Us == WHITE ? BLACK : WHITE); + constexpr Color Them = ~Us; constexpr Direction Down = -pawn_push(Us); constexpr Bitboard OutpostRanks = (Us == WHITE ? Rank4BB | Rank5BB | Rank6BB : Rank5BB | Rank4BB | Rank3BB); @@ -268,10 +399,10 @@ namespace { // 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)) - : pos.attacks_from(s); + : attacks_bb(s, pos.pieces()); if (pos.blockers_for_king(Us) & s) - b &= LineBB[pos.square(Us)][s]; + b &= line_bb(pos.square(Us), s); attackedBy2[Us] |= attackedBy[Us][ALL_PIECES] & b; attackedBy[Us][Pt] |= b; @@ -284,35 +415,53 @@ namespace { 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) { - // 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 += Outpost * (Pt == KNIGHT ? 2 : 1); - + // Bonus if the piece is on an outpost square or can reach one + // Reduced bonus for knights (BadOutpost) if few relevant targets + bb = OutpostRanks & (attackedBy[Us][PAWN] | shift(pos.pieces(PAWN))) + & ~pe->pawn_attacks_span(Them); + Bitboard targets = pos.pieces(Them) & ~pos.pieces(PAWN); + + if ( Pt == KNIGHT + && bb & s & ~CenterFiles // on a side outpost + && !(b & targets) // no relevant attacks + && (!more_than_one(targets & (s & QueenSide ? QueenSide : KingSide)))) + score += BadOutpost; + else if (bb & s) + score += Outpost[Pt == BISHOP]; else if (Pt == KNIGHT && bb & b & ~pos.pieces(Us)) score += ReachableOutpost; - // Knight and Bishop bonus for being right behind a pawn + // 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 -= KingProtector * distance(s, pos.square(Us)); + score -= KingProtector[Pt == BISHOP] * distance(pos.square(Us), s); if (Pt == BISHOP) { - // Penalty according to number of pawns on the same color square as the - // bishop, bigger when the center files are blocked with pawns. + // 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) - * (1 + popcount(blocked & CenterFiles)); + score -= BishopPawns[edge_distance(file_of(s))] * 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)) @@ -335,20 +484,28 @@ namespace { 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 + // 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)); + } } } @@ -368,10 +525,11 @@ namespace { // Evaluation::king() assigns bonuses and penalties to a king of a given color + template template Score Evaluation::king() const { - constexpr Color Them = (Us == WHITE ? BLACK : WHITE); + constexpr Color Them = ~Us; constexpr Bitboard Camp = (Us == WHITE ? AllSquares ^ Rank6BB ^ Rank7BB ^ Rank8BB : AllSquares ^ Rank1BB ^ Rank2BB ^ Rank3BB); @@ -396,41 +554,33 @@ namespace { b2 = attacks_bb(ksq, pos.pieces() ^ pos.pieces(Us, QUEEN)); // Enemy rooks checks - rookChecks = b1 & safe & attackedBy[Them][ROOK]; - + rookChecks = b1 & attackedBy[Them][ROOK] & safe; if (rookChecks) - kingDanger += RookSafeCheck; + kingDanger += SafeCheck[ROOK][more_than_one(rookChecks)]; 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; - + // Enemy queen safe checks: count them only if the checks are from squares from + // which opponent cannot give a rook check, because rook checks are more valuable. + queenChecks = (b1 | b2) & attackedBy[Them][QUEEN] & safe + & ~(attackedBy[Us][QUEEN] | rookChecks); if (queenChecks) - kingDanger += QueenSafeCheck; + kingDanger += SafeCheck[QUEEN][more_than_one(queenChecks)]; - // 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 + // Enemy bishops checks: count them only if they are from squares from which + // opponent cannot give a queen check, because queen checks are more valuable. + bishopChecks = b2 & attackedBy[Them][BISHOP] & safe & ~queenChecks; - if (bishopChecks) - kingDanger += BishopSafeCheck; + kingDanger += SafeCheck[BISHOP][more_than_one(bishopChecks)]; + else unsafeChecks |= b2 & attackedBy[Them][BISHOP]; // Enemy knights checks - knightChecks = pos.attacks_from(ksq) & attackedBy[Them][KNIGHT]; - + knightChecks = attacks_bb(ksq) & attackedBy[Them][KNIGHT]; if (knightChecks & safe) - kingDanger += KnightSafeCheck; + kingDanger += SafeCheck[KNIGHT][more_than_one(knightChecks & safe)]; else unsafeChecks |= knightChecks; @@ -440,21 +590,21 @@ namespace { b2 = b1 & attackedBy2[Them]; b3 = attackedBy[Us][ALL_PIECES] & KingFlank[file_of(ksq)] & Camp; - int kingFlankAttack = popcount(b1) + popcount(b2); + 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; + kingDanger += kingAttackersCount[Them] * kingAttackersWeight[Them] // (~10 Elo) + + 185 * 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) + + 3 * kingFlankAttack * kingFlankAttack / 8 // (~0.5 Elo) + + mg_value(mobility[Them] - mobility[Us]) // (~0.5 Elo) + - 873 * !pos.count(Them) // (~24 Elo) + - 100 * bool(attackedBy[Us][KNIGHT] & attackedBy[Us][KING]) // (~5 Elo) + - 6 * mg_value(score) / 8 // (~8 Elo) + - 4 * kingFlankDefense // (~5 Elo) + + 37; // (~0.5 Elo) // Transform the kingDanger units into a Score, and subtract it from the evaluation if (kingDanger > 100) @@ -476,10 +626,11 @@ namespace { // 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 == WHITE ? BLACK : WHITE); + constexpr Color Them = ~Us; constexpr Direction Up = pawn_push(Us); constexpr Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB); @@ -517,14 +668,16 @@ namespace { 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 - // Greater bonus when landing square is occupied b = attackedBy[Them][ALL_PIECES] & ~stronglyProtected & attackedBy[Us][ALL_PIECES]; - score += RestrictedPiece * (popcount(b) + popcount(b & pos.pieces())); + score += RestrictedPiece * popcount(b); // Protected or unattacked squares safe = ~attackedBy[Them][ALL_PIECES] | attackedBy[Us][ALL_PIECES]; @@ -548,17 +701,21 @@ namespace { // Bonus for threats on the next moves against enemy queen if (pos.count(Them) == 1) { + bool queenImbalance = pos.count() == 1; + Square s = pos.square(Them); - safe = mobilityArea[Us] & ~stronglyProtected; + safe = mobilityArea[Us] + & ~pos.pieces(Us, PAWN) + & ~stronglyProtected; - b = attackedBy[Us][KNIGHT] & pos.attacks_from(s); + b = attackedBy[Us][KNIGHT] & attacks_bb(s); - score += KnightOnQueen * popcount(b & safe); + score += KnightOnQueen * popcount(b & safe) * (1 + queenImbalance); - b = (attackedBy[Us][BISHOP] & pos.attacks_from(s)) - | (attackedBy[Us][ROOK ] & pos.attacks_from(s)); + b = (attackedBy[Us][BISHOP] & attacks_bb(s, pos.pieces())) + | (attackedBy[Us][ROOK ] & attacks_bb(s, pos.pieces())); - score += SliderOnQueen * popcount(b & safe & attackedBy2[Us]); + score += SliderOnQueen * popcount(b & safe & attackedBy2[Us]) * (1 + queenImbalance); } if (T) @@ -573,18 +730,32 @@ namespace { template template Score Evaluation::passed() const { - constexpr Color Them = (Us == WHITE ? BLACK : WHITE); + 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; + Bitboard b, bb, squaresToQueen, unsafeSquares, blockedPassers, helpers; Score score = SCORE_ZERO; b = pe->passed_pawns(Us); + 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); + } + while (b) { Square s = pop_lsb(&b); @@ -601,8 +772,8 @@ namespace { 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); + 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) @@ -635,13 +806,7 @@ namespace { } } // r > RANK_3 - // 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) & (s + Up))) - bonus = bonus / 2; - - score += bonus - PassedFile * map_to_queenside(file_of(s)); + score += bonus - PassedFile * edge_distance(file_of(s)); } if (T) @@ -651,20 +816,19 @@ namespace { } - // 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. + // 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 four 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 == WHITE ? BLACK : WHITE); + constexpr Color Them = ~Us; constexpr Direction Down = -pawn_push(Us); constexpr Bitboard SpaceMask = Us == WHITE ? CenterFiles & (Rank2BB | Rank3BB | Rank4BB) @@ -681,7 +845,7 @@ namespace { behind |= shift(behind); int bonus = popcount(safe) + popcount(behind & safe & ~attackedBy[Them][ALL_PIECES]); - int weight = pos.count(Us) - 1; + int weight = pos.count(Us) - 3 + std::min(pe->blocked_count(), 9); Score score = make_score(bonus * weight * weight / 16, 0); if (T) @@ -691,73 +855,89 @@ namespace { } - // 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. + // Evaluation::winnable() adjusts the midgame and endgame score components, based on + // the known attacking/defending status of the players. The final value is derived + // by interpolation from the midgame and endgame values. template - Score Evaluation::initiative(Score score) const { - - Value mg = mg_value(score); - Value eg = eg_value(score); + Value Evaluation::winnable(Score score) const { int outflanking = distance(pos.square(WHITE), pos.square(BLACK)) - distance(pos.square(WHITE), pos.square(BLACK)); - bool infiltration = rank_of(pos.square(WHITE)) > RANK_4 - || rank_of(pos.square(BLACK)) < RANK_5; - bool pawnsOnBothFlanks = (pos.pieces(PAWN) & QueenSide) && (pos.pieces(PAWN) & KingSide); - bool almostUnwinnable = !pe->passed_count() - && outflanking < 0 + 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() - + 11 * pos.count() + + 12 * pos.count() + 9 * outflanking - + 12 * infiltration + 21 * pawnsOnBothFlanks + + 24 * infiltration + 51 * !pos.non_pawn_material() - 43 * almostUnwinnable - - 100 ; + -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)) * std::max(std::min(complexity + 50, 0), -abs(mg)); + int u = ((mg > 0) - (mg < 0)) * std::clamp(complexity + 50, -abs(mg), 0); int v = ((eg > 0) - (eg < 0)) * std::max(complexity, -abs(eg)); - if (T) - Trace::add(INITIATIVE, make_score(u, v)); - - return make_score(u, v); - } - - - // Evaluation::scale_factor() computes the scale factor for the winning side - - template - ScaleFactor Evaluation::scale_factor(Value eg) const { + 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 scale factor is not already specific, scale down via general heuristics if (sf == SCALE_FACTOR_NORMAL) { - if ( pos.opposite_bishops() - && pos.non_pawn_material() == 2 * BishopValueMg) - sf = 22 ; + 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 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; + else if (pos.count() == 1) + sf = 37 + 3 * (pos.count(WHITE) == 1 ? pos.count(BLACK) + pos.count(BLACK) + : pos.count(WHITE) + pos.count(WHITE)); else - sf = std::min(sf, 36 + (pos.opposite_bishops() ? 2 : 7) * pos.count(strongSide)); + sf = std::min(sf, 36 + 7 * pos.count(strongSide)) - 4 * !pawnsOnBothFlanks; + + sf -= 4 * !pawnsOnBothFlanks; + } + + // 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; - sf = std::max(0, sf - (pos.rule50_count() - 12) / 4); + 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)); } - return ScaleFactor(sf); + return Value(v); } @@ -788,16 +968,19 @@ namespace { 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; + auto lazy_skip = [&](Value lazyThreshold) { + return abs(mg_value(score) + eg_value(score)) / 2 > lazyThreshold + pos.non_pawn_material() / 64; + }; - // Main evaluation begins here + if (lazy_skip(LazyThreshold1)) + goto make_v; + // Main evaluation begins here initialize(); initialize(); - // Pieces should be evaluated first (populate attack tables) + // 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() @@ -805,19 +988,19 @@ namespace { score += mobility[WHITE] - mobility[BLACK]; + // More complex interactions that require fully populated attack bitboards score += king< WHITE>() - king< BLACK>() - + threats() - threats() - + passed< WHITE>() - passed< BLACK>() - + space< WHITE>() - space< BLACK>(); + + passed< WHITE>() - passed< BLACK>(); - score += initiative(score); + if (lazy_skip(LazyThreshold2)) + goto make_v; - // Interpolate between a middlegame and a (scaled by 'sf') endgame 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; + score += threats() - threats() + + space< WHITE>() - space< BLACK>(); - v /= PHASE_MIDGAME; +make_v: + // Derive single value from mg and eg parts of score + Value v = winnable(score); // In case of tracing add all remaining individual evaluation terms if (T) @@ -826,11 +1009,15 @@ namespace { Trace::add(IMBALANCE, me->imbalance()); Trace::add(PAWN, pe->pawn_score(WHITE), pe->pawn_score(BLACK)); Trace::add(MOBILITY, mobility[WHITE], mobility[BLACK]); - Trace::add(TOTAL, score); } - return (pos.side_to_move() == WHITE ? v : -v) // Side to move point of view - + Eval::Tempo; + // Evaluation grain + v = (v / 16) * 16; + + // Side to move point of view + v = (pos.side_to_move() == WHITE ? v : -v) + Tempo; + + return v; } } // namespace @@ -840,28 +1027,70 @@ namespace { /// evaluation of the position from the point of view of the side to move. Value Eval::evaluate(const Position& pos) { - return Evaluation(pos).value(); -} + Value v; + + if (!Eval::useNNUE) + v = Evaluation(pos).value(); + else + { + // Scale and shift NNUE for compatibility with search and classical evaluation + auto adjusted_NNUE = [&](){ + int mat = pos.non_pawn_material() + PawnValueMg * pos.count(); + return NNUE::evaluate(pos) * (720 + mat / 32) / 1024 + Tempo; + }; + + // If there is PSQ imbalance use classical eval, with small probability if it is small + Value psq = Value(abs(eg_value(pos.psq_score()))); + int r50 = 16 + pos.rule50_count(); + bool largePsq = psq * 16 > (NNUEThreshold1 + pos.non_pawn_material() / 64) * r50; + bool classical = largePsq || (psq > PawnValueMg / 4 && !(pos.this_thread()->nodes & 0xB)); + + 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 && !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(); + } + + // Damp down the evaluation linearly when shuffling + v = v * (100 - pos.rule50_count()) / 100; + + // 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); + + return v; +} /// 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. +/// Trace scores are from white's point of view std::string Eval::trace(const Position& pos) { if (pos.checkers()) - return "Total evaluation: none (in check)"; + return "Final evaluation: none (in check)"; + + std::stringstream ss; + ss << std::showpoint << std::noshowpos << std::fixed << std::setprecision(2); + + Value v; std::memset(scores, 0, sizeof(scores)); pos.this_thread()->contempt = SCORE_ZERO; // Reset any dynamic contempt - Value v = Evaluation(pos).value(); - - v = pos.side_to_move() == WHITE ? v : -v; // Trace scores are from white's point of view + v = Evaluation(pos).value(); - 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" @@ -878,11 +1107,24 @@ std::string Eval::trace(const Position& pos) { << " Threats | " << Term(THREAT) << " Passed | " << Term(PASSED) << " Space | " << Term(SPACE) - << " Initiative | " << Term(INITIATIVE) + << " Winnable | " << Term(WINNABLE) << " ------------+-------------+-------------+------------\n" << " Total | " << Term(TOTAL); - ss << "\nTotal evaluation: " << to_cp(v) << " (white side)\n"; + v = pos.side_to_move() == WHITE ? v : -v; + + ss << "\nClassical evaluation: " << to_cp(v) << " (white side)\n"; + + if (Eval::useNNUE) + { + v = NNUE::evaluate(pos); + v = pos.side_to_move() == WHITE ? v : -v; + ss << "\nNNUE evaluation: " << to_cp(v) << " (white side)\n"; + } + + v = evaluate(pos); + v = pos.side_to_move() == WHITE ? v : -v; + ss << "\nFinal evaluation: " << to_cp(v) << " (white side)\n"; return ss.str(); }