X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fevaluate.cpp;h=2f9cec5cb2891ef48f043c79ff0ed4886f6a387c;hb=45b05328b6d10b1f72786a59d78ae95c17ec40dd;hp=8e5a7f82042d7d88a22ca39f013e3b9473793e40;hpb=7837fb2aca6db425e5f7237f5cc714412fc0140d;p=stockfish diff --git a/src/evaluate.cpp b/src/evaluate.cpp index 8e5a7f82..c945cf53 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -1,7 +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) 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 @@ -19,887 +18,1131 @@ #include #include +#include #include // For std::memset +#include #include #include +#include +#include +#include -#include "bitcount.h" +#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" -namespace { - // Struct EvalInfo contains various information computed and collected - // by the evaluation functions. - struct EvalInfo { +// 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 - // Pointers to material and pawn hash table entries - Material::Entry* mi; - Pawns::Entry* pi; - // attackedBy[color][piece type] is a bitboard representing all squares - // attacked by a given color and piece type, attackedBy[color][ALL_PIECES] - // contains all squares attacked by the given color. - Bitboard attackedBy[COLOR_NB][PIECE_TYPE_NB]; +using namespace std; +using namespace Eval::NNUE; - // 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 the three (or two, for a king on an edge file) - // 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]; +namespace Eval { - // 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]; + bool useNNUE; + string eval_file_loaded = "None"; - // kingAttackersWeight[color] is the sum of the "weight" 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]; + /// 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); + } - // kingAdjacentZoneAttacksCount[color] is the number of attacks to squares - // directly adjacent to the king of the given color. Pieces which attack - // more than one square are counted multiple times. For instance, if black's - // king is on g8 and there's a white knight on g5, this knight adds - // 2 to kingAdjacentZoneAttacksCount[BLACK]. - int kingAdjacentZoneAttacksCount[COLOR_NB]; + 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 { - Bitboard pinnedPieces[COLOR_NB]; + 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 }; - namespace Tracing { + Score scores[TERM_NB][COLOR_NB]; - enum Terms { // First 8 entries are for PieceType - MATERIAL = 8, IMBALANCE, MOBILITY, THREAT, PASSED, SPACE, TOTAL, TERMS_NB - }; + double to_cp(Value v) { return double(v) / PawnValueEg; } - Score scores[COLOR_NB][TERMS_NB]; - EvalInfo ei; - ScaleFactor sf; + void add(int idx, Color c, Score s) { + scores[idx][c] = s; + } - double to_cp(Value v); - void write(int idx, Color c, Score s); - void write(int idx, Score w, Score b = SCORE_ZERO); - void print(std::stringstream& ss, const char* name, int idx); - std::string do_trace(const Position& pos); + void add(int idx, Score w, Score b = SCORE_ZERO) { + scores[idx][WHITE] = w; + scores[idx][BLACK] = b; } - // Evaluation weights, indexed by evaluation term - enum { Mobility, PawnStructure, PassedPawns, Space, KingSafety }; - const struct Weight { int mg, eg; } Weights[] = { - {289, 344}, {233, 201}, {221, 273}, {46, 0}, {324, 0} + 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 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 }; + + // 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 V(v) Value(v) - #define S(mg, eg) make_score(mg, eg) - - // MobilityBonus[PieceType][attacked] contains bonuses for middle and end - // game, indexed by piece type and number of attacked squares not occupied by - // friendly pieces. - const Score MobilityBonus[][32] = { - {}, {}, - { S(-65,-50), S(-42,-30), S(-9,-10), S( 3, 0), S(15, 10), S(27, 20), // Knights - S( 37, 28), S( 42, 31), S(44, 33) }, - { S(-52,-47), S(-28,-23), S( 6, 1), S(20, 15), S(34, 29), S(48, 43), // Bishops - S( 60, 55), S( 68, 63), S(74, 68), S(77, 72), S(80, 75), S(82, 77), - S( 84, 79), S( 86, 81) }, - { S(-47,-53), S(-31,-26), S(-5, 0), S( 1, 16), S( 7, 32), S(13, 48), // Rooks - S( 18, 64), S( 22, 80), S(26, 96), S(29,109), S(31,115), S(33,119), - S( 35,122), S( 36,123), S(37,124) }, - { S(-42,-40), S(-28,-23), S(-5, -7), S( 0, 0), S( 6, 10), S(11, 19), // Queens - S( 13, 29), S( 18, 38), S(20, 40), S(21, 41), S(22, 41), S(22, 41), - S( 22, 41), S( 23, 41), S(24, 41), S(25, 41), S(25, 41), S(25, 41), - S( 25, 41), S( 25, 41), S(25, 41), S(25, 41), S(25, 41), S(25, 41), - S( 25, 41), S( 25, 41), S(25, 41), S(25, 41) } +#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,-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) } }; - // Outpost[PieceType][Square] contains bonuses for knights and bishops outposts, - // indexed by piece type and square (from white's point of view). - const Value Outpost[][SQUARE_NB] = { - {// A B C D E F G H - V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // Knights - V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), - V(0), V(0), V(4), V(8), V(8), V(4), V(0), V(0), - V(0), V(4),V(17),V(26),V(26),V(17), V(4), V(0), - V(0), V(8),V(26),V(35),V(35),V(26), V(8), V(0), - V(0), V(4),V(17),V(17),V(17),V(17), V(4), V(0) }, - { - V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), // Bishops - V(0), V(0), V(0), V(0), V(0), V(0), V(0), V(0), - V(0), V(0), V(5), V(5), V(5), V(5), V(0), V(0), - V(0), V(5),V(10),V(10),V(10),V(10), V(5), V(0), - V(0),V(10),V(21),V(21),V(21),V(21),V(10), V(0), - V(0), V(5), V(8), V(8), V(8), V(8), V(5), V(0) } + // 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) }; - // Threat[defended/weak][minor/major attacking][attacked PieceType] contains - // bonuses according to which piece type attacks which one. - const Score Threat[][2][PIECE_TYPE_NB] = { - { { S(0, 0), S( 0, 0), S(19, 37), S(24, 37), S(44, 97), S(35,106) }, // Defended Minor - { S(0, 0), S( 0, 0), S( 9, 14), S( 9, 14), S( 7, 14), S(24, 48) } }, // Defended Major - { { S(0, 0), S( 0,32), S(33, 41), S(31, 50), S(41,100), S(35,104) }, // Weak Minor - { S(0, 0), S( 0,27), S(26, 57), S(26, 57), S(0 , 43), S(23, 51) } } // Weak Major + // 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(7, 27), S(16, 32), S(17, 40), S(64, 71), S(170, 174), S(278, 262) }; - // ThreatenedByPawn[PieceType] contains a penalty according to which piece - // type is attacked by an enemy pawn. - const Score ThreatenedByPawn[] = { - S(0, 0), S(0, 0), S(87, 118), S(84, 122), S(114, 203), S(121, 217) + constexpr Score RookOnClosedFile = S(10, 5); + constexpr Score RookOnOpenFile[] = { S(19, 6), S(47, 26) }; + + // 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(55, 41), S(77, 56), S(89, 119), S(79, 162) }; - // Assorted bonuses and penalties used by evaluation - const Score KingOnOne = S( 2, 58); - const Score KingOnMany = S( 6,125); - const Score RookOnPawn = S( 7, 27); - const Score RookOnOpenFile = S(43, 21); - const Score RookOnSemiOpenFile = S(19, 10); - const Score BishopPawns = S( 8, 12); - const Score MinorBehindPawn = S(16, 0); - const Score TrappedRook = S(92, 0); - const Score Unstoppable = S( 0, 20); - const Score Hanging = S(31, 26); - - // Penalty for a bishop on a1/h1 (a8/h8 for black) which is trapped by - // a friendly pawn on b2/g2 (b7/g7 for black). This can obviously only - // happen in Chess960 games. - const Score TrappedBishopA1H1 = S(50, 50); - - #undef S - #undef V - - // SpaceMask[Color] contains the area of the board which is considered - // by the space evaluation. In the middlegame, each side is given a bonus - // based on how many squares inside this area are safe and available for - // friendly minor pieces. - const Bitboard SpaceMask[] = { - (FileCBB | FileDBB | FileEBB | FileFBB) & (Rank2BB | Rank3BB | Rank4BB), - (FileCBB | FileDBB | FileEBB | FileFBB) & (Rank7BB | Rank6BB | Rank5BB) + constexpr Score ThreatByRook[PIECE_TYPE_NB] = { + S(0, 0), S(3, 44), S(37, 68), S(42, 60), S(0, 39), S(58, 43) }; - // King danger constants and variables. The king danger scores are looked-up - // in KingDanger[]. Various little "meta-bonuses" measuring the strength - // of the enemy attack are added up into an integer, which is used as an - // index to KingDanger[]. - // - // KingAttackWeights[PieceType] contains king attack weights by piece type - const int KingAttackWeights[] = { 0, 0, 8, 4, 4, 1 }; - - // Bonuses for enemy's safe checks - const int QueenContactCheck = 89; - const int RookContactCheck = 72; - const int QueenCheck = 51; - const int RookCheck = 38; - const int BishopCheck = 5; - const int KnightCheck = 16; - - // KingDanger[attackUnits] contains the actual king danger weighted - // scores, indexed by a calculated integer number. - Score KingDanger[512]; - - // apply_weight() weighs score 's' by weight 'w' trying to prevent overflow - Score apply_weight(Score s, const Weight& w) { - return make_score(mg_value(s) * w.mg / 256, eg_value(s) * w.eg / 256); - } + // Assorted bonuses and penalties + 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 + + // 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]; - // init_eval_info() initializes king bitboards for given color adding - // pawn attacks. To be done at the beginning of the evaluation. + // 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]; - template - void init_eval_info(const Position& pos, EvalInfo& ei) { + // kingRing[color] are the squares adjacent to the king plus some other + // very near squares, depending on king position. + Bitboard kingRing[COLOR_NB]; - const Color Them = (Us == WHITE ? BLACK : WHITE); - const Square Down = (Us == WHITE ? DELTA_S : DELTA_N); + // 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]; - ei.pinnedPieces[Us] = pos.pinned_pieces(Us); + // 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]; - Bitboard b = ei.attackedBy[Them][KING] = pos.attacks_from(pos.king_square(Them)); - ei.attackedBy[Us][ALL_PIECES] = ei.attackedBy[Us][PAWN] = ei.pi->pawn_attacks(Us); + // 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]; + }; - // Init king safety tables only if we are going to use them - if (pos.non_pawn_material(Us) >= QueenValueMg) - { - ei.kingRing[Them] = b | shift_bb(b); - b &= ei.attackedBy[Us][PAWN]; - ei.kingAttackersCount[Us] = b ? popcount(b) : 0; - ei.kingAdjacentZoneAttacksCount[Us] = ei.kingAttackersWeight[Us] = 0; - } - else - ei.kingRing[Them] = ei.kingAttackersCount[Us] = 0; - } + // 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. - // evaluate_outpost() evaluates bishop and knight outpost squares + template template + void Evaluation::initialize() { - template - Score evaluate_outpost(const Position& pos, const EvalInfo& ei, Square s) { + constexpr Color Them = ~Us; + constexpr Direction Up = pawn_push(Us); + constexpr Direction Down = -Up; + constexpr Bitboard LowRanks = (Us == WHITE ? Rank2BB | Rank3BB : Rank7BB | Rank6BB); - const Color Them = (Us == WHITE ? BLACK : WHITE); + const Square ksq = pos.square(Us); - assert (Pt == BISHOP || Pt == KNIGHT); + Bitboard dblAttackByPawn = pawn_double_attacks_bb(pos.pieces(Us, PAWN)); - // Initial bonus based on square - Value bonus = Outpost[Pt == BISHOP][relative_square(Us, s)]; + // Find our pawns that are blocked or on the first two ranks + Bitboard b = pos.pieces(Us, PAWN) & (shift(pos.pieces()) | LowRanks); - // Increase bonus if supported by pawn, especially if the opponent has - // no minor piece which can trade with the outpost piece. - if (bonus && (ei.attackedBy[Us][PAWN] & s)) - { - if ( !pos.pieces(Them, KNIGHT) - && !(squares_of_color(s) & pos.pieces(Them, BISHOP))) - bonus += bonus + bonus / 2; - else - bonus += bonus / 2; - } + // 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)); - return make_score(bonus * 2, bonus / 2); + // 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(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; + + // Remove from kingRing[] the squares defended by two pawns + kingRing[Us] &= ~dblAttackByPawn; } - // evaluate_pieces() assigns bonuses and penalties to the pieces of a given color + // Evaluation::pieces() scores pieces of a given color and type - template - Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score* mobility, Bitboard* mobilityArea) { + template template + Score Evaluation::pieces() { - Bitboard b; - Square s; + constexpr Color Them = ~Us; + constexpr Direction Down = -pawn_push(Us); + constexpr Bitboard OutpostRanks = (Us == WHITE ? Rank4BB | Rank5BB | Rank6BB + : Rank5BB | Rank4BB | Rank3BB); + Bitboard b1 = pos.pieces(Us, Pt); + Bitboard b, bb; Score score = SCORE_ZERO; - const PieceType NextPt = (Us == WHITE ? Pt : PieceType(Pt + 1)); - const Color Them = (Us == WHITE ? BLACK : WHITE); - const Square* pl = pos.list(Us); + attackedBy[Us][Pt] = 0; - ei.attackedBy[Us][Pt] = 0; + while (b1) { + Square s = pop_lsb(&b1); - while ((s = *pl++) != SQ_NONE) - { // Find attacked squares, including x-ray attacks for bishops and rooks - b = Pt == BISHOP ? attacks_bb(s, pos.pieces() ^ pos.pieces(Us, QUEEN)) - : Pt == ROOK ? attacks_bb< ROOK>(s, pos.pieces() ^ pos.pieces(Us, ROOK, QUEEN)) - : pos.attacks_from(s); + 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 (ei.pinnedPieces[Us] & s) - b &= LineBB[pos.king_square(Us)][s]; + if (pos.blockers_for_king(Us) & s) + b &= line_bb(pos.square(Us), s); - ei.attackedBy[Us][ALL_PIECES] |= ei.attackedBy[Us][Pt] |= b; + attackedBy2[Us] |= attackedBy[Us][ALL_PIECES] & b; + attackedBy[Us][Pt] |= b; + attackedBy[Us][ALL_PIECES] |= b; - if (b & ei.kingRing[Them]) + if (b & kingRing[Them]) { - ei.kingAttackersCount[Us]++; - ei.kingAttackersWeight[Us] += KingAttackWeights[Pt]; - Bitboard bb = b & ei.attackedBy[Them][KING]; - if (bb) - ei.kingAdjacentZoneAttacksCount[Us] += popcount(bb); + kingAttackersCount[Us]++; + kingAttackersWeight[Us] += KingAttackWeights[Pt]; + kingAttacksCount[Us] += popcount(b & attackedBy[Them][KING]); } - if (Pt == QUEEN) - b &= ~( ei.attackedBy[Them][KNIGHT] - | ei.attackedBy[Them][BISHOP] - | ei.attackedBy[Them][ROOK]); + else if (Pt == ROOK && (file_bb(s) & kingRing[Them])) + score += RookOnKingRing; - int mob = Pt != QUEEN ? popcount(b & mobilityArea[Us]) - : popcount(b & mobilityArea[Us]); + else if (Pt == BISHOP && (attacks_bb(s, pos.pieces(PAWN)) & kingRing[Them])) + score += BishopOnKingRing; - mobility[Us] += MobilityBonus[Pt][mob]; + int mob = popcount(b & mobilityArea[Us]); - // Decrease score if we are attacked by an enemy pawn. The remaining part - // of threat evaluation must be done later when we have full attack info. - if (ei.attackedBy[Them][PAWN] & s) - score -= ThreatenedByPawn[Pt]; + mobility[Us] += MobilityBonus[Pt - 2][mob]; if (Pt == BISHOP || Pt == KNIGHT) { - // Bonus for outpost square - if (!(pos.pieces(Them, PAWN) & pawn_attack_span(Us, s))) - score += evaluate_outpost(pos, ei, s); - - // Bonus when behind a pawn - if ( relative_rank(Us, s) < RANK_5 - && (pos.pieces(PAWN) & (s + pawn_push(Us)))) + // 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; + + // Bonus for a knight or bishop shielded by pawn + if (shift(pos.pieces(PAWN)) & s) score += MinorBehindPawn; - // Penalty for pawns on same color square of bishop + // Penalty if the piece is far from the king + score -= KingProtector[Pt == BISHOP] * distance(pos.square(Us), s); + if (Pt == BISHOP) - score -= BishopPawns * ei.pi->pawns_on_same_color_squares(Us, s); - - // 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 ( Pt == BISHOP - && pos.is_chess960() - && (s == relative_square(Us, SQ_A1) || s == relative_square(Us, SQ_H1))) { - Square d = pawn_push(Us) + (file_of(s) == FILE_A ? DELTA_E : DELTA_W); - 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; + // 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[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)) + 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; + } } } if (Pt == ROOK) { - // Bonus for aligning with enemy pawns on the same rank/file - if (relative_rank(Us, s) >= RANK_5) + // Bonuses for rook on a (semi-)open or closed file + if (pos.is_on_semiopen_file(Us, s)) { - Bitboard alignedPawns = pos.pieces(Them, PAWN) & PseudoAttacks[ROOK][s]; - if (alignedPawns) - score += popcount(alignedPawns) * RookOnPawn; + score += RookOnOpenFile[pos.is_on_semiopen_file(Them, s)]; } - - // Bonus when on an open or semi-open file - if (ei.pi->semiopen_file(Us, file_of(s))) - score += ei.pi->semiopen_file(Them, file_of(s)) ? RookOnOpenFile : RookOnSemiOpenFile; - - // Penalize when trapped by the king, even more if king cannot castle - if (mob <= 3 && !ei.pi->semiopen_file(Us, file_of(s))) + else { - Square ksq = pos.king_square(Us); - - if ( ((file_of(ksq) < FILE_E) == (file_of(s) < file_of(ksq))) - && (rank_of(ksq) == rank_of(s) || relative_rank(Us, ksq) == RANK_1) - && !ei.pi->semiopen_side(Us, file_of(ksq), file_of(s) < file_of(ksq))) - score -= (TrappedRook - make_score(mob * 22, 0)) * (1 + !pos.can_castle(Us)); + // 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)); + } } } - } - if (Trace) - Tracing::write(Pt, Us, score); + 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; + } + } + if (T) + Trace::add(Pt, Us, score); - // Recursively call evaluate_pieces() of next piece type until KING excluded - return score - evaluate_pieces(pos, ei, mobility, mobilityArea); + return score; } - template<> - Score evaluate_pieces(const Position&, EvalInfo&, Score*, Bitboard*) { return SCORE_ZERO; } - template<> - Score evaluate_pieces(const Position&, EvalInfo&, Score*, Bitboard*) { return SCORE_ZERO; } + // Evaluation::king() assigns bonuses and penalties to a king of a given color - // evaluate_king() assigns bonuses and penalties to a king of a given color + template template + Score Evaluation::king() const { - template - Score evaluate_king(const Position& pos, const EvalInfo& ei) { + constexpr Color Them = ~Us; + constexpr Bitboard Camp = (Us == WHITE ? AllSquares ^ Rank6BB ^ Rank7BB ^ Rank8BB + : AllSquares ^ Rank1BB ^ Rank2BB ^ Rank3BB); - const Color Them = (Us == WHITE ? BLACK : WHITE); + Bitboard weak, b1, b2, b3, safe, unsafeChecks = 0; + Bitboard rookChecks, queenChecks, bishopChecks, knightChecks; + int kingDanger = 0; + const Square ksq = pos.square(Us); - Bitboard undefended, b, b1, b2, safe; - int attackUnits; - const Square ksq = pos.king_square(Us); + // Init the score with king shelter and enemy pawns storm + Score score = pe->king_safety(pos); - // King shelter and enemy pawns storm - Score score = ei.pi->king_safety(pos, ksq); + // 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]); - // Main king safety evaluation - if (ei.kingAttackersCount[Them]) - { - // Find the attacked squares around the king which have no defenders - // apart from the king itself - undefended = ei.attackedBy[Them][ALL_PIECES] - & ei.attackedBy[Us][KING] - & ~( ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT] - | ei.attackedBy[Us][BISHOP] | ei.attackedBy[Us][ROOK] - | ei.attackedBy[Us][QUEEN]); - - // Initialize the 'attackUnits' variable, which is used later on as an - // index into the KingDanger[] array. The initial value is based on the - // number and types of the enemy's attacking pieces, the number of - // attacked and undefended squares around our king and the quality of - // the pawn shelter (current 'score' value). - attackUnits = std::min(74, ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) - + 9 * ei.kingAdjacentZoneAttacksCount[Them] - + 25 * popcount(undefended) - + 10 * (ei.pinnedPieces[Us] != 0) - - mg_value(score) / 8 - - !pos.count(Them) * 60; - - // Analyse the enemy's safe queen contact checks. Firstly, find the - // undefended squares around the king reachable by the enemy queen... - b = undefended & ei.attackedBy[Them][QUEEN] & ~pos.pieces(Them); - if (b) - { - // ...and then remove squares not supported by another enemy piece - b &= ei.attackedBy[Them][PAWN] | ei.attackedBy[Them][KNIGHT] - | ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][ROOK]; + // Analyse the safe enemy's checks which are possible on next move + safe = ~pos.pieces(Them); + safe &= ~attackedBy[Us][ALL_PIECES] | (weak & attackedBy2[Them]); - if (b) - attackUnits += QueenContactCheck * popcount(b); - } + 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 & attackedBy[Them][ROOK] & safe; + if (rookChecks) + kingDanger += SafeCheck[ROOK][more_than_one(rookChecks)]; + else + unsafeChecks |= b1 & attackedBy[Them][ROOK]; + + // 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 += SafeCheck[QUEEN][more_than_one(queenChecks)]; + + // 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 += SafeCheck[BISHOP][more_than_one(bishopChecks)]; - // Analyse the enemy's safe rook contact checks. Firstly, find the - // undefended squares around the king reachable by the enemy rooks... - b = undefended & ei.attackedBy[Them][ROOK] & ~pos.pieces(Them); + else + unsafeChecks |= b2 & attackedBy[Them][BISHOP]; - // Consider only squares where the enemy's rook gives check - b &= PseudoAttacks[ROOK][ksq]; + // Enemy knights checks + knightChecks = attacks_bb(ksq) & attackedBy[Them][KNIGHT]; + if (knightChecks & safe) + kingDanger += SafeCheck[KNIGHT][more_than_one(knightChecks & safe)]; + 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] // (~10 Elo) + + 183 * popcount(kingRing[Us] & weak) // (~15 Elo) + + 148 * popcount(unsafeChecks) // (~4 Elo) + + 98 * popcount(pos.blockers_for_king(Us)) // (~2 Elo) + + 69 * kingAttacksCount[Them] // (~0.5 Elo) + + 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) + 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); - if (b) - { - // ...and then remove squares not supported by another enemy piece - b &= ( ei.attackedBy[Them][PAWN] | ei.attackedBy[Them][KNIGHT] - | ei.attackedBy[Them][BISHOP] | ei.attackedBy[Them][QUEEN]); + return score; + } - if (b) - attackUnits += RookContactCheck * popcount(b); - } - // Analyse the enemy's safe distance checks for sliders and knights - safe = ~(ei.attackedBy[Us][ALL_PIECES] | pos.pieces(Them)); + // Evaluation::threats() assigns bonuses according to the types of the + // attacking and the attacked pieces. - b1 = pos.attacks_from(ksq) & safe; - b2 = pos.attacks_from(ksq) & safe; + template template + Score Evaluation::threats() const { - // Enemy queen safe checks - b = (b1 | b2) & ei.attackedBy[Them][QUEEN]; - if (b) - attackUnits += QueenCheck * popcount(b); + constexpr Color Them = ~Us; + constexpr Direction Up = pawn_push(Us); + constexpr Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB); - // Enemy rooks safe checks - b = b1 & ei.attackedBy[Them][ROOK]; - if (b) - attackUnits += RookCheck * popcount(b); + Bitboard b, weak, defended, nonPawnEnemies, stronglyProtected, safe; + Score score = SCORE_ZERO; - // Enemy bishops safe checks - b = b2 & ei.attackedBy[Them][BISHOP]; - if (b) - attackUnits += BishopCheck * popcount(b); + // Non-pawn enemies + nonPawnEnemies = pos.pieces(Them) & ~pos.pieces(PAWN); - // Enemy knights safe checks - b = pos.attacks_from(ksq) & ei.attackedBy[Them][KNIGHT] & safe; - if (b) - attackUnits += KnightCheck * popcount(b); + // 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]); - // Finally, extract the king danger score from the KingDanger[] - // array and subtract the score from evaluation. - score -= KingDanger[std::max(std::min(attackUnits, 399), 0)]; - } + // Non-pawn enemies, strongly protected + defended = nonPawnEnemies & stronglyProtected; - if (Trace) - Tracing::write(KING, Us, score); + // Enemies not strongly protected and under our attack + weak = pos.pieces(Them) & ~stronglyProtected & attackedBy[Us][ALL_PIECES]; - return score; - } + // 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)))]; - // evaluate_threats() assigns bonuses according to the type of attacking piece - // and the type of attacked one. + if (weak & attackedBy[Us][KING]) + score += ThreatByKing; - template - Score evaluate_threats(const Position& pos, const EvalInfo& ei) { + b = ~attackedBy[Them][ALL_PIECES] + | (nonPawnEnemies & attackedBy2[Us]); + score += Hanging * popcount(weak & b); - const Color Them = (Us == WHITE ? BLACK : WHITE); + // Additional bonus if weak piece is only protected by a queen + score += WeakQueenProtection * popcount(weak & attackedBy[Them][QUEEN]); + } - enum { Defended, Weak }; - enum { Minor, Major }; + // Bonus for restricting their piece moves + b = attackedBy[Them][ALL_PIECES] + & ~stronglyProtected + & attackedBy[Us][ALL_PIECES]; + score += RestrictedPiece * popcount(b); - Bitboard b, weak, defended; - Score score = SCORE_ZERO; + // Protected or unattacked squares + safe = ~attackedBy[Them][ALL_PIECES] | attackedBy[Us][ALL_PIECES]; - // Non-pawn enemies defended by a pawn - defended = (pos.pieces(Them) ^ pos.pieces(Them, PAWN)) - & ei.attackedBy[Them][PAWN]; + // 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); - // Add a bonus according to the kind of attacking pieces - if (defended) - { - b = defended & (ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP]); - while (b) - score += Threat[Defended][Minor][type_of(pos.piece_on(pop_lsb(&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(); - b = defended & (ei.attackedBy[Us][ROOK]); - while (b) - score += Threat[Defended][Major][type_of(pos.piece_on(pop_lsb(&b)))]; - } + // Keep only the squares which are relatively safe + b &= ~attackedBy[Them][PAWN] & safe; - // Enemies not defended by a pawn and under our attack - weak = pos.pieces(Them) - & ~ei.attackedBy[Them][PAWN] - & ei.attackedBy[Us][ALL_PIECES]; + // Bonus for safe pawn threats on the next move + b = pawn_attacks_bb(b) & nonPawnEnemies; + score += ThreatByPawnPush * popcount(b); - // Add a bonus according to the kind of attacking pieces - if (weak) + // Bonus for threats on the next moves against enemy queen + if (pos.count(Them) == 1) { - b = weak & (ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP]); - while (b) - score += Threat[Weak][Minor][type_of(pos.piece_on(pop_lsb(&b)))]; + bool queenImbalance = pos.count() == 1; - b = weak & (ei.attackedBy[Us][ROOK] | ei.attackedBy[Us][QUEEN]); - while (b) - score += Threat[Weak][Major][type_of(pos.piece_on(pop_lsb(&b)))]; + Square s = pos.square(Them); + safe = mobilityArea[Us] + & ~pos.pieces(Us, PAWN) + & ~stronglyProtected; + + b = attackedBy[Us][KNIGHT] & attacks_bb(s); + + score += KnightOnQueen * popcount(b & safe) * (1 + queenImbalance); - b = weak & ~ei.attackedBy[Them][ALL_PIECES]; - if (b) - score += Hanging * popcount(b); + b = (attackedBy[Us][BISHOP] & attacks_bb(s, pos.pieces())) + | (attackedBy[Us][ROOK ] & attacks_bb(s, pos.pieces())); - b = weak & ei.attackedBy[Us][KING]; - if (b) - score += more_than_one(b) ? KingOnMany : KingOnOne; + score += SliderOnQueen * popcount(b & safe & attackedBy2[Us]) * (1 + queenImbalance); } - if (Trace) - Tracing::write(Tracing::THREAT, Us, score); + if (T) + Trace::add(THREAT, Us, score); return score; } + // Evaluation::passed() evaluates the passed pawns and candidate passed + // pawns of the given color. - // evaluate_passed_pawns() evaluates the passed pawns of the given color + template template + Score Evaluation::passed() const { - template - Score evaluate_passed_pawns(const Position& pos, const EvalInfo& ei) { + constexpr Color Them = ~Us; + constexpr Direction Up = pawn_push(Us); + constexpr Direction Down = -Up; - const Color Them = (Us == WHITE ? BLACK : WHITE); + auto king_proximity = [&](Color c, Square s) { + return std::min(distance(pos.square(c), s), 5); + }; - Bitboard b, squaresToQueen, defendedSquares, unsafeSquares; + Bitboard b, bb, squaresToQueen, unsafeSquares, blockedPassers, helpers; Score score = SCORE_ZERO; - b = ei.pi->passed_pawns(Us); + 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); - assert(pos.pawn_passed(Us, s)); + assert(!(pos.pieces(Them, PAWN) & forward_file_bb(Us, s + Up))); - int r = relative_rank(Us, s) - RANK_2; - int rr = r * (r - 1); + int r = relative_rank(Us, s); - // Base bonus based on rank - Value mbonus = Value(17 * rr), ebonus = Value(7 * (rr + r + 1)); + Score bonus = PassedRank[r]; - if (rr) + if (r > RANK_3) { - Square blockSq = s + pawn_push(Us); + int w = 5 * r - 13; + Square blockSq = s + Up; // Adjust bonus based on the king's proximity - ebonus += distance(pos.king_square(Them), blockSq) * 5 * rr - - distance(pos.king_square(Us ), blockSq) * 2 * rr; + 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 (relative_rank(Us, blockSq) != RANK_8) - ebonus -= distance(pos.king_square(Us), blockSq + pawn_push(Us)) * rr; + 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)) { - // If there is a rook or queen attacking/defending the pawn from behind, - // consider all the squaresToQueen. Otherwise consider only the squares - // in the pawn's path attacked or occupied by the enemy. - defendedSquares = unsafeSquares = squaresToQueen = forward_bb(Us, s); - - Bitboard bb = forward_bb(Them, s) & pos.pieces(ROOK, QUEEN) & pos.attacks_from(s); + squaresToQueen = forward_file_bb(Us, s); + unsafeSquares = passed_pawn_span(Us, s); - if (!(pos.pieces(Us) & bb)) - defendedSquares &= ei.attackedBy[Us][ALL_PIECES]; + bb = forward_file_bb(Them, s) & pos.pieces(ROOK, QUEEN); if (!(pos.pieces(Them) & bb)) - unsafeSquares &= ei.attackedBy[Them][ALL_PIECES] | pos.pieces(Them); - - // If there aren't any enemy attacks, assign a big bonus. Otherwise - // assign a smaller bonus if the block square isn't attacked. - int k = !unsafeSquares ? 15 : !(unsafeSquares & blockSq) ? 9 : 0; - - // If the path to queen is fully defended, assign a big bonus. - // Otherwise assign a smaller bonus if the block square is defended. - if (defendedSquares == squaresToQueen) - k += 6; - - else if (defendedSquares & blockSq) - k += 4; - - mbonus += k * rr, ebonus += k * rr; + unsafeSquares &= attackedBy[Them][ALL_PIECES] | pos.pieces(Them); + + // If there are no enemy pieces or attacks on passed pawn span, assign a big bonus. + // Or if there is some, but they are all attacked by our pawns, assign a bit smaller 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 ? 36 : + !(unsafeSquares & ~attackedBy[Us][PAWN]) ? 30 : + !(unsafeSquares & squaresToQueen) ? 17 : + !(unsafeSquares & blockSq) ? 7 : + 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); } - else if (pos.pieces(Us) & blockSq) - mbonus += rr * 3 + r * 2 + 3, ebonus += rr + r * 2; - } // rr != 0 + } // r > RANK_3 - if (pos.count(Us) < pos.count(Them)) - ebonus += ebonus / 4; - - score += make_score(mbonus, ebonus); + score += bonus - PassedFile * edge_distance(file_of(s)); } - if (Trace) - Tracing::write(Tracing::PASSED, Us, apply_weight(score, Weights[PassedPawns])); + if (T) + Trace::add(PASSED, Us, score); - // Add the scores to the middlegame and endgame eval - return apply_weight(score, Weights[PassedPawns]); + return score; } - // evaluate_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 - Score evaluate_space(const Position& pos, const EvalInfo& ei) { + // 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 { - const Color Them = (Us == WHITE ? BLACK : WHITE); + // Early exit if, for example, both queens or 6 minor pieces have been exchanged + 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. - Bitboard safe = SpaceMask[Us] + 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) - & ~ei.attackedBy[Them][PAWN] - & (ei.attackedBy[Us][ALL_PIECES] | ~ei.attackedBy[Them][ALL_PIECES]); + & ~attackedBy[Them][PAWN]; // Find all squares which are at most three squares behind some friendly pawn Bitboard behind = pos.pieces(Us, PAWN); - behind |= (Us == WHITE ? behind >> 8 : behind << 8); - behind |= (Us == WHITE ? behind >> 16 : behind << 16); + behind |= shift(behind); + behind |= shift(behind); - // Since SpaceMask[Us] is fully on our half of the board - assert(unsigned(safe >> (Us == WHITE ? 32 : 0)) == 0); + // Compute space score based on the number of safe squares and number of our pieces + // increased with number of total blocked pawns in position. + int bonus = popcount(safe) + popcount(behind & safe & ~attackedBy[Them][ALL_PIECES]); + int weight = pos.count(Us) - 3 + std::min(pe->blocked_count(), 9); + Score score = make_score(bonus * weight * weight / 16, 0); - // Count safe + (behind & safe) with a single popcount - int bonus = popcount((Us == WHITE ? safe << 32 : safe >> 32) | (behind & safe)); - int weight = pos.count(Us) + pos.count(Us) - + pos.count(Them) + pos.count(Them); + if (T) + Trace::add(SPACE, Us, score); - return make_score(bonus * weight * weight, 0); + return score; } - // do_evaluate() is the evaluation entry point, called directly from evaluate() - - template - Value do_evaluate(const Position& pos) { + // 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. - assert(!pos.checkers()); - - EvalInfo ei; - Score score, mobility[2] = { SCORE_ZERO, SCORE_ZERO }; + template + Value Evaluation::winnable(Score score) const { - // Initialize score by reading the incrementally updated scores included - // in the position object (material + piece square tables). - // Score is computed from the point of view of white. - score = pos.psq_score(); + int outflanking = distance(pos.square(WHITE), pos.square(BLACK)) + - distance(pos.square(WHITE), pos.square(BLACK)); - // Probe the material hash table - ei.mi = Material::probe(pos); - score += ei.mi->imbalance(); - - // If we have a specialized evaluation function for the current material - // configuration, call it and return. - if (ei.mi->specialized_eval_exists()) - return ei.mi->evaluate(pos); - - // Probe the pawn hash table - ei.pi = Pawns::probe(pos); - score += apply_weight(ei.pi->pawns_score(), Weights[PawnStructure]); + bool pawnsOnBothFlanks = (pos.pieces(PAWN) & QueenSide) + && (pos.pieces(PAWN) & KingSide); - // Initialize attack and king safety bitboards - init_eval_info(pos, ei); - init_eval_info(pos, ei); + bool almostUnwinnable = outflanking < 0 + && !pawnsOnBothFlanks; - ei.attackedBy[WHITE][ALL_PIECES] |= ei.attackedBy[WHITE][KING]; - ei.attackedBy[BLACK][ALL_PIECES] |= ei.attackedBy[BLACK][KING]; + bool infiltration = rank_of(pos.square(WHITE)) > RANK_4 + || rank_of(pos.square(BLACK)) < RANK_5; - // Do not include in mobility squares protected by enemy pawns or occupied by our pawns or king - Bitboard mobilityArea[] = { ~(ei.attackedBy[BLACK][PAWN] | pos.pieces(WHITE, PAWN, KING)), - ~(ei.attackedBy[WHITE][PAWN] | pos.pieces(BLACK, PAWN, KING)) }; + // 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 ; - // Evaluate pieces and mobility - score += evaluate_pieces(pos, ei, mobility, mobilityArea); - score += apply_weight(mobility[WHITE] - mobility[BLACK], Weights[Mobility]); + Value mg = mg_value(score); + Value eg = eg_value(score); - // Evaluate kings after all other pieces because we need complete attack - // information when computing the king safety evaluation. - score += evaluate_king(pos, ei) - - evaluate_king(pos, ei); + // 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::clamp(complexity + 50, -abs(mg), 0); + int v = ((eg > 0) - (eg < 0)) * std::max(complexity, -abs(eg)); - // Evaluate tactical threats, we need full attack information including king - score += evaluate_threats(pos, ei) - - evaluate_threats(pos, ei); + mg += u; + eg += v; - // Evaluate passed pawns, we need full attack information including king - score += evaluate_passed_pawns(pos, ei) - - evaluate_passed_pawns(pos, ei); + // Compute the scale factor for the winning side + Color strongSide = eg > VALUE_DRAW ? WHITE : BLACK; + int sf = me->scale_factor(pos, strongSide); - // If both sides have only pawns, score for potential unstoppable pawns - if (!pos.non_pawn_material(WHITE) && !pos.non_pawn_material(BLACK)) - { - Bitboard b; - if ((b = ei.pi->passed_pawns(WHITE)) != 0) - score += int(relative_rank(WHITE, frontmost_sq(WHITE, b))) * Unstoppable; - - if ((b = ei.pi->passed_pawns(BLACK)) != 0) - score -= int(relative_rank(BLACK, frontmost_sq(BLACK, b))) * Unstoppable; - } - - // Evaluate space for both sides, only during opening - if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) >= 2 * QueenValueMg + 4 * RookValueMg + 2 * KnightValueMg) - { - Score s = evaluate_space(pos, ei) - evaluate_space(pos, ei); - score += apply_weight(s, Weights[Space]); - } - - // Scale winning side if position is more drawish than it appears - Color strongSide = eg_value(score) > VALUE_DRAW ? WHITE : BLACK; - ScaleFactor sf = ei.mi->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. - if ( ei.mi->game_phase() < PHASE_MIDGAME - && (sf == SCALE_FACTOR_NORMAL || sf == SCALE_FACTOR_ONEPAWN)) + // If scale factor is not already specific, scale down via general heuristics + if (sf == SCALE_FACTOR_NORMAL) { if (pos.opposite_bishops()) { - // Endgame with opposite-colored bishops and no other pieces (ignoring pawns) - // is almost a draw, in case of KBP vs KB is even more a draw. + // For pure opposite colored bishops endgames use scale factor + // based on the number of passed pawns of the strong side. if ( pos.non_pawn_material(WHITE) == BishopValueMg && pos.non_pawn_material(BLACK) == BishopValueMg) - sf = more_than_one(pos.pieces(PAWN)) ? ScaleFactor(32) : ScaleFactor(8); - - // Endgame with opposite-colored bishops, but also other pieces. Still - // a bit drawish, but not as drawish as with only the two bishops. + sf = 18 + 4 * popcount(pe->passed_pawns(strongSide)); + // For every other opposite colored bishops endgames use scale factor + // based on the number of all pieces of the strong side. else - sf = ScaleFactor(50 * sf / SCALE_FACTOR_NORMAL); + sf = 22 + 3 * pos.count(strongSide); } - // Endings where weaker side can place his king in front of the opponent's - // pawns are drawish. - else if ( abs(eg_value(score)) <= BishopValueEg - && ei.pi->pawn_span(strongSide) <= 1 - && !pos.pawn_passed(~strongSide, pos.king_square(~strongSide))) - sf = ei.pi->pawn_span(strongSide) ? ScaleFactor(56) : ScaleFactor(38); - } + // For rook endgames with strong side not having overwhelming pawn number advantage + // and its pawns being on one flank and weak side protecting its pieces with a king + // use lower scale factor. + else if ( pos.non_pawn_material(WHITE) == RookValueMg + && pos.non_pawn_material(BLACK) == RookValueMg + && pos.count(strongSide) - pos.count(~strongSide) <= 1 + && bool(KingSide & pos.pieces(strongSide, PAWN)) != bool(QueenSide & pos.pieces(strongSide, PAWN)) + && (attacks_bb(pos.square(~strongSide)) & pos.pieces(~strongSide, PAWN))) + sf = 36; + // For queen vs no queen endgames use scale factor + // based on number of minors of side that doesn't have queen. + else if (pos.count() == 1) + sf = 37 + 3 * (pos.count(WHITE) == 1 ? pos.count(BLACK) + pos.count(BLACK) + : pos.count(WHITE) + pos.count(WHITE)); + // In every other case use scale factor based on + // the number of pawns of the strong side reduced if pawns are on a single flank. + else + sf = std::min(sf, 36 + 7 * pos.count(strongSide)) - 4 * !pawnsOnBothFlanks; - // Interpolate between a middlegame and a (scaled by 'sf') endgame score - Value v = mg_value(score) * int(ei.mi->game_phase()) - + eg_value(score) * int(PHASE_MIDGAME - ei.mi->game_phase()) * sf / SCALE_FACTOR_NORMAL; + // Reduce scale factor in case of pawns being on a single flank + sf -= 4 * !pawnsOnBothFlanks; + } - v /= int(PHASE_MIDGAME); + // 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; - // In case of tracing add all single evaluation contributions for both white and black - if (Trace) + if (T) { - Tracing::write(Tracing::MATERIAL, pos.psq_score()); - Tracing::write(Tracing::IMBALANCE, ei.mi->imbalance()); - Tracing::write(PAWN, ei.pi->pawns_score()); - Tracing::write(Tracing::MOBILITY, apply_weight(mobility[WHITE], Weights[Mobility]) - , apply_weight(mobility[BLACK], Weights[Mobility])); - Tracing::write(Tracing::SPACE, apply_weight(evaluate_space(pos, ei), Weights[Space]) - , apply_weight(evaluate_space(pos, ei), Weights[Space])); - Tracing::write(Tracing::TOTAL, score); - Tracing::ei = ei; - Tracing::sf = sf; + 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 (pos.side_to_move() == WHITE ? v : -v) + Eval::Tempo; + return Value(v); } - // Tracing function definitions + // 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. - double Tracing::to_cp(Value v) { return double(v) / PawnValueEg; } + template + Value Evaluation::value() { - void Tracing::write(int idx, Color c, Score s) { scores[c][idx] = s; } + assert(!pos.checkers()); - void Tracing::write(int idx, Score w, Score b) { + // Probe the material hash table + me = Material::probe(pos); - write(idx, WHITE, w); - write(idx, BLACK, b); - } + // 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); - void Tracing::print(std::stringstream& ss, const char* name, int idx) { - - Score wScore = scores[WHITE][idx]; - Score bScore = scores[BLACK][idx]; - - switch (idx) { - case MATERIAL: case IMBALANCE: case PAWN: case TOTAL: - ss << std::setw(15) << name << " | --- --- | --- --- | " - << std::setw(5) << to_cp(mg_value(wScore - bScore)) << " " - << std::setw(5) << to_cp(eg_value(wScore - bScore)) << " \n"; - break; - default: - ss << std::setw(15) << name << " | " << std::noshowpos - << std::setw(5) << to_cp(mg_value(wScore)) << " " - << std::setw(5) << to_cp(eg_value(wScore)) << " | " - << std::setw(5) << to_cp(mg_value(bScore)) << " " - << std::setw(5) << to_cp(eg_value(bScore)) << " | " - << std::setw(5) << to_cp(mg_value(wScore - bScore)) << " " - << std::setw(5) << to_cp(eg_value(wScore - bScore)) << " \n"; - } - } + // 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 + auto lazy_skip = [&](Value lazyThreshold) { + return abs(mg_value(score) + eg_value(score)) / 2 > lazyThreshold + pos.non_pawn_material() / 64; + }; - std::string Tracing::do_trace(const Position& pos) { + if (lazy_skip(LazyThreshold1)) + goto make_v; - std::memset(scores, 0, sizeof(scores)); + // Main evaluation begins here + initialize(); + initialize(); - Value v = do_evaluate(pos); - v = pos.side_to_move() == WHITE ? v : -v; // White's point of view + // 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(); - 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"; + score += mobility[WHITE] - mobility[BLACK]; - print(ss, "Material", MATERIAL); - print(ss, "Imbalance", IMBALANCE); - print(ss, "Pawns", PAWN); - print(ss, "Knights", KNIGHT); - print(ss, "Bishops", BISHOP); - print(ss, "Rooks", ROOK); - print(ss, "Queens", QUEEN); - print(ss, "Mobility", MOBILITY); - print(ss, "King safety", KING); - print(ss, "Threats", THREAT); - print(ss, "Passed pawns", PASSED); - print(ss, "Space", SPACE); + // More complex interactions that require fully populated attack bitboards + score += king< WHITE>() - king< BLACK>() + + passed< WHITE>() - passed< BLACK>(); - ss << "----------------+-------------+-------------+-------------\n"; - print(ss, "Total", TOTAL); + if (lazy_skip(LazyThreshold2)) + goto make_v; - ss << "\nTotal Evaluation: " << to_cp(v) << " (white side)\n"; + score += threats() - threats() + + space< WHITE>() - space< BLACK>(); - return ss.str(); +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) + { + 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]); + } + + // Evaluation grain + v = (v / 16) * 16; + + // Side to move point of view + v = (pos.side_to_move() == WHITE ? v : -v) + Tempo; + + return v; } } // namespace -namespace Eval { +/// 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) { - /// evaluate() is the main evaluation function. It returns a static evaluation - /// of the position always from the point of view of the side to move. + Value v; - Value evaluate(const Position& pos) { - return do_evaluate(pos); + 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) * (679 + 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)); + + // Use classical evaluation for really low piece endgames. + // The most critical case is a bishop + A/H file pawn vs naked king draw. + bool strongClassical = pos.non_pawn_material() < 2 * RookValueMg && pos.count() < 2; + + v = classical || strongClassical ? Evaluation(pos).value() : adjusted_NNUE(); + + // If the classical eval is small and imbalance large, use NNUE nevertheless. + // For the case of opposite colored bishops, switch to NNUE eval with + // small probability if the classical eval is less than the threshold. + if ( largePsq && !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; - /// 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. It's mainly used for - /// debugging. - std::string trace(const Position& pos) { - return Tracing::do_trace(pos); - } + // 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; +} - /// init() computes evaluation weights, usually at startup +/// 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 - void init() { +std::string Eval::trace(const Position& pos) { - const double MaxSlope = 8.5; - const double Peak = 1280; - double t = 0.0; + if (pos.checkers()) + return "Final evaluation: none (in check)"; - for (int i = 1; i < 400; ++i) - { - t = std::min(Peak, std::min(0.027 * i * i, t + MaxSlope)); - KingDanger[i] = apply_weight(make_score(int(t), 0), Weights[KingSafety]); - } + 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 + + v = Evaluation(pos).value(); + + 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 = 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"; } -} // namespace Eval + v = evaluate(pos); + v = pos.side_to_move() == WHITE ? v : -v; + ss << "\nFinal evaluation: " << to_cp(v) << " (white side)\n"; + + return ss.str(); +}