/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
- Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+ Copyright (C) 2004-2023 The Stockfish developers (see AUTHORS file)
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
+#include "evaluate.h"
+
#include <algorithm>
#include <cassert>
+#include <cmath>
#include <cstdlib>
-#include <cstring> // For std::memset
#include <fstream>
#include <iomanip>
-#include <sstream>
#include <iostream>
-#include <streambuf>
+#include <sstream>
#include <vector>
-#include "bitboard.h"
-#include "evaluate.h"
-#include "material.h"
+#include "incbin/incbin.h"
#include "misc.h"
-#include "pawns.h"
+#include "nnue/evaluate_nnue.h"
+#include "position.h"
#include "thread.h"
-#include "timeman.h"
+#include "types.h"
#include "uci.h"
-#include "incbin/incbin.h"
-
// Macro to embed the default efficiently updatable neural network (NNUE) file
// data in the engine binary (using incbin.h, by Dale Weiler).
// const unsigned int gEmbeddedNNUESize; // the size of the embedded file
// Note that this does not work in Microsoft Visual Studio.
#if !defined(_MSC_VER) && !defined(NNUE_EMBEDDING_OFF)
- INCBIN(EmbeddedNNUE, EvalFileDefaultName);
+INCBIN(EmbeddedNNUE, EvalFileDefaultName);
#else
- const unsigned char gEmbeddedNNUEData[1] = {0x0};
- const unsigned char *const gEmbeddedNNUEEnd = &gEmbeddedNNUEData[1];
- const unsigned int gEmbeddedNNUESize = 1;
+const unsigned char gEmbeddedNNUEData[1] = {0x0};
+const unsigned char* const gEmbeddedNNUEEnd = &gEmbeddedNNUEData[1];
+const unsigned int gEmbeddedNNUESize = 1;
#endif
-using namespace std;
-
namespace Stockfish {
namespace Eval {
- bool useNNUE;
- string currentEvalFileName = "None";
+std::string currentEvalFileName = "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.
+// 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() {
- void NNUE::init() {
-
- useNNUE = Options["Use NNUE"];
- if (!useNNUE)
- return;
-
- string eval_file = string(Options["EvalFile"]);
+ std::string eval_file = std::string(Options["EvalFile"]);
if (eval_file.empty())
eval_file = EvalFileDefaultName;
- #if defined(DEFAULT_NNUE_DIRECTORY)
- #define stringify2(x) #x
- #define stringify(x) stringify2(x)
- vector<string> dirs = { "<internal>" , "" , CommandLine::binaryDirectory , stringify(DEFAULT_NNUE_DIRECTORY) };
- #else
- vector<string> dirs = { "<internal>" , "" , CommandLine::binaryDirectory };
- #endif
+#if defined(DEFAULT_NNUE_DIRECTORY)
+ std::vector<std::string> dirs = {"<internal>", "", CommandLine::binaryDirectory,
+ stringify(DEFAULT_NNUE_DIRECTORY)};
+#else
+ std::vector<std::string> dirs = {"<internal>", "", CommandLine::binaryDirectory};
+#endif
- for (string directory : dirs)
+ for (const std::string& directory : dirs)
if (currentEvalFileName != eval_file)
{
if (directory != "<internal>")
{
- ifstream stream(directory + eval_file, ios::binary);
- if (load_eval(eval_file, stream))
+ std::ifstream stream(directory + eval_file, std::ios::binary);
+ if (NNUE::load_eval(eval_file, stream))
currentEvalFileName = eval_file;
}
if (directory == "<internal>" && eval_file == EvalFileDefaultName)
{
// C++ way to prepare a buffer for a memory stream
- class MemoryBuffer : public basic_streambuf<char> {
- public: MemoryBuffer(char* p, size_t n) { setg(p, p, p + n); setp(p, p + n); }
+ class MemoryBuffer: public std::basic_streambuf<char> {
+ public:
+ MemoryBuffer(char* p, size_t n) {
+ setg(p, p, p + n);
+ setp(p, p + n);
+ }
};
- MemoryBuffer buffer(const_cast<char*>(reinterpret_cast<const char*>(gEmbeddedNNUEData)),
- size_t(gEmbeddedNNUESize));
+ MemoryBuffer buffer(
+ const_cast<char*>(reinterpret_cast<const char*>(gEmbeddedNNUEData)),
+ size_t(gEmbeddedNNUESize));
+ (void) gEmbeddedNNUEEnd; // Silence warning on unused variable
- istream stream(&buffer);
- if (load_eval(eval_file, stream))
+ std::istream stream(&buffer);
+ if (NNUE::load_eval(eval_file, stream))
currentEvalFileName = eval_file;
}
}
- }
+}
- /// NNUE::verify() verifies that the last net used was loaded successfully
- void NNUE::verify() {
+// Verifies that the last net used was loaded successfully
+void NNUE::verify() {
- string eval_file = string(Options["EvalFile"]);
+ std::string eval_file = std::string(Options["EvalFile"]);
if (eval_file.empty())
eval_file = EvalFileDefaultName;
- if (useNNUE && currentEvalFileName != eval_file)
+ if (currentEvalFileName != eval_file)
{
- 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/" + std::string(EvalFileDefaultName);
- string msg5 = "The engine will be terminated now.";
+ std::string msg1 =
+ "Network evaluation parameters compatible with the engine must be available.";
+ std::string msg2 = "The network file " + eval_file + " was not loaded successfully.";
+ std::string msg3 = "The UCI option EvalFile might need to specify the full path, "
+ "including the directory name, to the network file.";
+ std::string msg4 = "The default net can be downloaded from: "
+ "https://tests.stockfishchess.org/api/nn/"
+ + std::string(EvalFileDefaultName);
+ std::string msg5 = "The engine will be terminated now.";
sync_cout << "info string ERROR: " << msg1 << sync_endl;
sync_cout << "info string ERROR: " << msg2 << sync_endl;
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;
- }
+ sync_cout << "info string NNUE evaluation using " << eval_file << 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, WINNABLE, TOTAL, TERM_NB
- };
-
- Score scores[TERM_NB][COLOR_NB];
-
- double to_cp(Value v) { return double(v) / PawnValueEg; }
-
- void add(int idx, Color c, Score s) {
- scores[idx][c] = s;
- }
-
- void add(int idx, Score w, Score b = SCORE_ZERO) {
- scores[idx][WHITE] = w;
- scores[idx][BLACK] = b;
- }
-
- std::ostream& operator<<(std::ostream& os, Score s) {
- os << std::setw(5) << to_cp(mg_value(s)) << " "
- << std::setw(5) << to_cp(eg_value(s));
- return os;
- }
-
- std::ostream& operator<<(std::ostream& os, Term t) {
-
- if (t == MATERIAL || t == IMBALANCE || t == WINNABLE || t == TOTAL)
- os << " ---- ----" << " | " << " ---- ----";
- else
- os << scores[t][WHITE] << " | " << scores[t][BLACK];
-
- os << " | " << scores[t][WHITE] - scores[t][BLACK] << " |\n";
- return os;
- }
}
-using namespace Trace;
-
-namespace {
-
- // Threshold for lazy and space evaluation
- constexpr Value LazyThreshold1 = Value(3130);
- constexpr Value LazyThreshold2 = Value(2204);
- constexpr Value SpaceThreshold = Value(11551);
-
- // 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 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) }
- };
-
- // 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(2, 8), S(3, 8)
- };
-
- // 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(57, 38), S(31, 24) };
-
- // 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)
- };
-
- 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)
- };
-
- constexpr Score ThreatByRook[PIECE_TYPE_NB] = {
- S(0, 0), S(3, 44), S(37, 68), S(42, 60), S(0, 39), S(58, 43)
- };
-
- constexpr Value CorneredBishop = Value(50);
-
- // Assorted bonuses and penalties
- constexpr Score UncontestedOutpost = S( 1, 10);
- constexpr Score BishopOnKingRing = S( 24, 0);
- constexpr Score BishopXRayPawns = S( 4, 5);
- 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<Tracing T>
- class Evaluation {
-
- public:
- Evaluation() = delete;
- explicit Evaluation(const Position& p) : pos(p) {}
- Evaluation& operator=(const Evaluation&) = delete;
- Value value();
-
- private:
- template<Color Us> void initialize();
- template<Color Us, PieceType Pt> Score pieces();
- template<Color Us> Score king() const;
- template<Color Us> Score threats() const;
- template<Color Us> Score passed() const;
- template<Color Us> Score space() const;
- Value winnable(Score score) const;
-
- const Position& pos;
- Material::Entry* me;
- Pawns::Entry* pe;
- Bitboard mobilityArea[COLOR_NB];
- Score mobility[COLOR_NB] = { SCORE_ZERO, SCORE_ZERO };
-
- // attackedBy[color][piece type] is a bitboard representing all squares
- // attacked by a given color and piece type. Special "piece types" which
- // is also calculated is ALL_PIECES.
- Bitboard attackedBy[COLOR_NB][PIECE_TYPE_NB];
-
- // attackedBy2[color] are the squares attacked by at least 2 units of a given
- // color, including x-rays. But diagonal x-rays through pawns are not computed.
- Bitboard attackedBy2[COLOR_NB];
-
- // kingRing[color] are the squares adjacent to the king plus some other
- // very near squares, depending on king position.
- Bitboard kingRing[COLOR_NB];
-
- // kingAttackersCount[color] is the number of pieces of the given color
- // which attack a square in the kingRing of the enemy king.
- int kingAttackersCount[COLOR_NB];
-
- // kingAttackersWeight[color] is the sum of the "weights" of the pieces of
- // the given color which attack a square in the kingRing of the enemy king.
- // The weights of the individual piece types are given by the elements in
- // the KingAttackWeights array.
- int kingAttackersWeight[COLOR_NB];
-
- // kingAttacksCount[color] is the number of attacks by the given color to
- // squares directly adjacent to the enemy king. Pieces which attack more
- // than one square are counted multiple times. For instance, if there is
- // a white knight on g5 and black's king is on g8, this white knight adds 2
- // to kingAttacksCount[WHITE].
- int kingAttacksCount[COLOR_NB];
- };
-
-
- // Evaluation::initialize() computes king and pawn attacks, and the king ring
- // bitboard for a given color. This is done at the beginning of the evaluation.
-
- template<Tracing T> template<Color Us>
- void Evaluation<T>::initialize() {
-
- constexpr Color Them = ~Us;
- constexpr Direction Up = pawn_push(Us);
- constexpr Direction Down = -Up;
- constexpr Bitboard LowRanks = (Us == WHITE ? Rank2BB | Rank3BB : Rank7BB | Rank6BB);
-
- const Square ksq = pos.square<KING>(Us);
-
- Bitboard dblAttackByPawn = pawn_double_attacks_bb<Us>(pos.pieces(Us, PAWN));
-
- // Find our pawns that are blocked or on the first two ranks
- Bitboard b = pos.pieces(Us, PAWN) & (shift<Down>(pos.pieces()) | LowRanks);
-
- // Squares occupied by those pawns, by our king or queen, by blockers to attacks on our king
- // or controlled by enemy pawns are excluded from the mobility area.
- mobilityArea[Us] = ~(b | pos.pieces(Us, KING, QUEEN) | pos.blockers_for_king(Us) | pe->pawn_attacks(Them));
-
- // Initialize attackedBy[] for king and pawns
- attackedBy[Us][KING] = attacks_bb<KING>(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<KING>(s) | s;
-
- kingAttackersCount[Them] = popcount(kingRing[Us] & pe->pawn_attacks(Them));
- kingAttacksCount[Them] = kingAttackersWeight[Them] = 0;
-
- // Remove from kingRing[] the squares defended by two pawns
- kingRing[Us] &= ~dblAttackByPawn;
- }
-
-
- // Evaluation::pieces() scores pieces of a given color and type
- template<Tracing T> template<Color Us, PieceType Pt>
- Score Evaluation<T>::pieces() {
-
- 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;
-
- attackedBy[Us][Pt] = 0;
-
- while (b1)
- {
- Square s = pop_lsb(b1);
-
- // Find attacked squares, including x-ray attacks for bishops and rooks
- b = Pt == BISHOP ? attacks_bb<BISHOP>(s, pos.pieces() ^ pos.pieces(QUEEN))
- : Pt == ROOK ? attacks_bb< ROOK>(s, pos.pieces() ^ pos.pieces(QUEEN) ^ pos.pieces(Us, ROOK))
- : attacks_bb<Pt>(s, pos.pieces());
-
- if (pos.blockers_for_king(Us) & s)
- b &= line_bb(pos.square<KING>(Us), s);
-
- attackedBy2[Us] |= attackedBy[Us][ALL_PIECES] & b;
- attackedBy[Us][Pt] |= b;
- attackedBy[Us][ALL_PIECES] |= b;
-
- if (b & kingRing[Them])
- {
- kingAttackersCount[Us]++;
- kingAttackersWeight[Us] += KingAttackWeights[Pt];
- kingAttacksCount[Us] += popcount(b & attackedBy[Them][KING]);
- }
-
- else if (Pt == ROOK && (file_bb(s) & kingRing[Them]))
- score += RookOnKingRing;
-
- else if (Pt == BISHOP && (attacks_bb<BISHOP>(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 the piece is on an outpost square or can reach one
- // Bonus for knights (UncontestedOutpost) if few relevant targets
- bb = OutpostRanks & (attackedBy[Us][PAWN] | shift<Down>(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 += UncontestedOutpost * popcount(pos.pieces(PAWN) & (s & QueenSide ? QueenSide : KingSide));
- 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<Down>(pos.pieces(PAWN)) & s)
- score += MinorBehindPawn;
-
- // Penalty if the piece is far from the king
- score -= KingProtector[Pt == BISHOP] * distance(pos.square<KING>(Us), s);
-
- if constexpr (Pt == BISHOP)
- {
- // 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<Down>(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<BISHOP>(s) & pos.pieces(Them, PAWN));
-
- // Bonus for bishop on a long diagonal which can "see" both center squares
- if (more_than_one(attacks_bb<BISHOP>(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)) ? 4 * make_score(CorneredBishop, CorneredBishop)
- : 3 * make_score(CorneredBishop, CorneredBishop);
- }
- }
- }
-
- if constexpr (Pt == ROOK)
- {
- // Bonuses for rook on a (semi-)open or closed file
- if (pos.is_on_semiopen_file(Us, s))
- {
- 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<Down>(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<KING>(Us));
- if ((kf < FILE_E) == (file_of(s) < kf))
- score -= TrappedRook * (1 + !pos.castling_rights(Us));
- }
- }
- }
-
- if constexpr (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 constexpr (T)
- Trace::add(Pt, Us, score);
-
- return score;
- }
-
-
- // Evaluation::king() assigns bonuses and penalties to a king of a given color
-
- template<Tracing T> template<Color Us>
- Score Evaluation<T>::king() const {
-
- constexpr Color Them = ~Us;
- constexpr Bitboard Camp = (Us == WHITE ? AllSquares ^ Rank6BB ^ Rank7BB ^ Rank8BB
- : AllSquares ^ Rank1BB ^ Rank2BB ^ Rank3BB);
-
- Bitboard weak, b1, b2, b3, safe, unsafeChecks = 0;
- Bitboard rookChecks, queenChecks, bishopChecks, knightChecks;
- int kingDanger = 0;
- const Square ksq = pos.square<KING>(Us);
-
- // Init the score with king shelter and enemy pawns storm
- Score score = pe->king_safety<Us>(pos);
-
- // Attacked squares defended at most once by our queen or king
- weak = attackedBy[Them][ALL_PIECES]
- & ~attackedBy2[Us]
- & (~attackedBy[Us][ALL_PIECES] | attackedBy[Us][KING] | attackedBy[Us][QUEEN]);
-
- // Analyse the safe enemy's checks which are possible on next move
- safe = ~pos.pieces(Them);
- safe &= ~attackedBy[Us][ALL_PIECES] | (weak & attackedBy2[Them]);
+// Returns a static, purely materialistic evaluation of the position from
+// the point of view of the given color. It can be divided by PawnValue to get
+// an approximation of the material advantage on the board in terms of pawns.
+Value Eval::simple_eval(const Position& pos, Color c) {
+ return PawnValue * (pos.count<PAWN>(c) - pos.count<PAWN>(~c))
+ + (pos.non_pawn_material(c) - pos.non_pawn_material(~c));
+}
- b1 = attacks_bb<ROOK >(ksq, pos.pieces() ^ pos.pieces(Us, QUEEN));
- b2 = attacks_bb<BISHOP>(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];
+// 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) {
- // 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)];
+ assert(!pos.checkers());
- // 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)];
+ Value v;
+ Color stm = pos.side_to_move();
+ int shuffling = pos.rule50_count();
+ int simpleEval = simple_eval(pos, stm) + (int(pos.key() & 7) - 3);
- else
- unsafeChecks |= b2 & attackedBy[Them][BISHOP];
+ bool lazy = std::abs(simpleEval) >= RookValue + KnightValue + 16 * shuffling * shuffling
+ + std::abs(pos.this_thread()->bestValue)
+ + std::abs(pos.this_thread()->rootSimpleEval);
- // Enemy knights checks
- knightChecks = attacks_bb<KNIGHT>(ksq) & attackedBy[Them][KNIGHT];
- if (knightChecks & safe)
- kingDanger += SafeCheck[KNIGHT][more_than_one(knightChecks & safe)];
+ if (lazy)
+ v = Value(simpleEval);
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<QUEEN>(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 constexpr (T)
- Trace::add(KING, Us, score);
-
- return score;
- }
-
-
- // Evaluation::threats() assigns bonuses according to the types of the
- // attacking and the attacked pieces.
-
- template<Tracing T> template<Color Us>
- Score Evaluation<T>::threats() const {
-
- constexpr Color Them = ~Us;
- constexpr Direction Up = pawn_push(Us);
- constexpr Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB);
-
- Bitboard b, weak, defended, nonPawnEnemies, stronglyProtected, safe;
- Score score = SCORE_ZERO;
-
- // Non-pawn enemies
- nonPawnEnemies = pos.pieces(Them) & ~pos.pieces(PAWN);
-
- // Squares strongly protected by the enemy, either because they defend the
- // square with a pawn, or because they defend the square twice and we don't.
- stronglyProtected = attackedBy[Them][PAWN]
- | (attackedBy2[Them] & ~attackedBy2[Us]);
-
- // Non-pawn enemies, strongly protected
- defended = nonPawnEnemies & stronglyProtected;
-
- // Enemies not strongly protected and under our attack
- weak = pos.pieces(Them) & ~stronglyProtected & attackedBy[Us][ALL_PIECES];
-
- // Bonus according to the kind of attacking pieces
- if (defended | weak)
- {
- b = (defended | weak) & (attackedBy[Us][KNIGHT] | attackedBy[Us][BISHOP]);
- while (b)
- score += ThreatByMinor[type_of(pos.piece_on(pop_lsb(b)))];
-
- b = weak & attackedBy[Us][ROOK];
- while (b)
- score += ThreatByRook[type_of(pos.piece_on(pop_lsb(b)))];
-
- if (weak & attackedBy[Us][KING])
- score += ThreatByKing;
-
- b = ~attackedBy[Them][ALL_PIECES]
- | (nonPawnEnemies & attackedBy2[Us]);
- score += Hanging * popcount(weak & b);
-
- // Additional bonus if weak piece is only protected by a queen
- score += WeakQueenProtection * popcount(weak & attackedBy[Them][QUEEN]);
- }
-
- // Bonus for restricting their piece moves
- b = attackedBy[Them][ALL_PIECES]
- & ~stronglyProtected
- & attackedBy[Us][ALL_PIECES];
- score += RestrictedPiece * popcount(b);
-
- // Protected or unattacked squares
- safe = ~attackedBy[Them][ALL_PIECES] | attackedBy[Us][ALL_PIECES];
-
- // Bonus for attacking enemy pieces with our relatively safe pawns
- b = pos.pieces(Us, PAWN) & safe;
- b = pawn_attacks_bb<Us>(b) & nonPawnEnemies;
- score += ThreatBySafePawn * popcount(b);
-
- // Find squares where our pawns can push on the next move
- b = shift<Up>(pos.pieces(Us, PAWN)) & ~pos.pieces();
- b |= shift<Up>(b & TRank3BB) & ~pos.pieces();
-
- // Keep only the squares which are relatively safe
- b &= ~attackedBy[Them][PAWN] & safe;
-
- // Bonus for safe pawn threats on the next move
- b = pawn_attacks_bb<Us>(b) & nonPawnEnemies;
- score += ThreatByPawnPush * popcount(b);
-
- // Bonus for threats on the next moves against enemy queen
- if (pos.count<QUEEN>(Them) == 1)
- {
- bool queenImbalance = pos.count<QUEEN>() == 1;
-
- Square s = pos.square<QUEEN>(Them);
- safe = mobilityArea[Us]
- & ~pos.pieces(Us, PAWN)
- & ~stronglyProtected;
-
- b = attackedBy[Us][KNIGHT] & attacks_bb<KNIGHT>(s);
-
- score += KnightOnQueen * popcount(b & safe) * (1 + queenImbalance);
-
- b = (attackedBy[Us][BISHOP] & attacks_bb<BISHOP>(s, pos.pieces()))
- | (attackedBy[Us][ROOK ] & attacks_bb<ROOK >(s, pos.pieces()));
-
- score += SliderOnQueen * popcount(b & safe & attackedBy2[Us]) * (1 + queenImbalance);
- }
-
- if constexpr (T)
- Trace::add(THREAT, Us, score);
-
- return score;
- }
-
- // Evaluation::passed() evaluates the passed pawns and candidate passed
- // pawns of the given color.
-
- template<Tracing T> template<Color Us>
- Score Evaluation<T>::passed() const {
-
- constexpr Color Them = ~Us;
- constexpr Direction Up = pawn_push(Us);
- constexpr Direction Down = -Up;
-
- auto king_proximity = [&](Color c, Square s) {
- return std::min(distance(pos.square<KING>(c), s), 5);
- };
-
- Bitboard b, bb, squaresToQueen, unsafeSquares, blockedPassers, helpers;
- Score score = SCORE_ZERO;
-
- b = pe->passed_pawns(Us);
-
- blockedPassers = b & shift<Down>(pos.pieces(Them, PAWN));
- if (blockedPassers)
- {
- helpers = shift<Up>(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<WEST>(helpers)
- | shift<EAST>(helpers);
- }
-
- while (b)
- {
- Square s = pop_lsb(b);
-
- assert(!(pos.pieces(Them, PAWN) & forward_file_bb(Us, s + Up)));
-
- int r = relative_rank(Us, s);
-
- Score bonus = PassedRank[r];
-
- if (r > RANK_3)
- {
- int w = 5 * r - 13;
- Square blockSq = s + Up;
-
- // Adjust bonus based on the king's proximity
- bonus += make_score(0, ( king_proximity(Them, blockSq) * 19 / 4
- - king_proximity(Us, blockSq) * 2) * w);
-
- // If blockSq is not the queening square then consider also a second push
- if (r != RANK_7)
- bonus -= make_score(0, king_proximity(Us, blockSq + Up) * w);
-
- // If the pawn is free to advance, then increase the bonus
- if (pos.empty(blockSq))
- {
- squaresToQueen = forward_file_bb(Us, s);
- unsafeSquares = passed_pawn_span(Us, s);
-
- bb = forward_file_bb(Them, s) & pos.pieces(ROOK, QUEEN);
-
- if (!(pos.pieces(Them) & bb))
- unsafeSquares &= attackedBy[Them][ALL_PIECES] | 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);
- }
- } // r > RANK_3
-
- score += bonus - PassedFile * edge_distance(file_of(s));
- }
-
- if constexpr (T)
- Trace::add(PASSED, Us, score);
-
- return score;
- }
-
-
- // Evaluation::space() computes a space evaluation for a given side, aiming to improve game
- // play in the opening. It is based on the number of safe squares on the 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<Tracing T> template<Color Us>
- Score Evaluation<T>::space() const {
-
- // Early exit if, for example, both queens or 6 minor pieces have been exchanged
- if (pos.non_pawn_material() < SpaceThreshold)
- return SCORE_ZERO;
-
- constexpr Color Them = ~Us;
- constexpr Direction Down = -pawn_push(Us);
- constexpr Bitboard SpaceMask =
- Us == WHITE ? CenterFiles & (Rank2BB | Rank3BB | Rank4BB)
- : CenterFiles & (Rank7BB | Rank6BB | Rank5BB);
-
- // Find the available squares for our pieces inside the area defined by SpaceMask
- Bitboard safe = SpaceMask
- & ~pos.pieces(Us, PAWN)
- & ~attackedBy[Them][PAWN];
-
- // Find all squares which are at most three squares behind some friendly pawn
- Bitboard behind = pos.pieces(Us, PAWN);
- behind |= shift<Down>(behind);
- behind |= shift<Down+Down>(behind);
-
- // Compute space score based on the number of safe squares and number of our pieces
- // increased with number of total blocked pawns in position.
- int bonus = popcount(safe) + popcount(behind & safe & ~attackedBy[Them][ALL_PIECES]);
- int weight = pos.count<ALL_PIECES>(Us) - 3 + std::min(pe->blocked_count(), 9);
- Score score = make_score(bonus * weight * weight / 16, 0);
-
- if constexpr (T)
- Trace::add(SPACE, Us, score);
-
- return score;
- }
-
-
- // 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<Tracing T>
- Value Evaluation<T>::winnable(Score score) const {
-
- int outflanking = distance<File>(pos.square<KING>(WHITE), pos.square<KING>(BLACK))
- + int(rank_of(pos.square<KING>(WHITE)) - rank_of(pos.square<KING>(BLACK)));
-
- bool pawnsOnBothFlanks = (pos.pieces(PAWN) & QueenSide)
- && (pos.pieces(PAWN) & KingSide);
-
- bool almostUnwinnable = outflanking < 0
- && !pawnsOnBothFlanks;
-
- bool infiltration = rank_of(pos.square<KING>(WHITE)) > RANK_4
- || rank_of(pos.square<KING>(BLACK)) < RANK_5;
-
- // Compute the initiative bonus for the attacking side
- int complexity = 9 * pe->passed_count()
- + 12 * pos.count<PAWN>()
- + 9 * outflanking
- + 21 * pawnsOnBothFlanks
- + 24 * infiltration
- + 51 * !pos.non_pawn_material()
- - 43 * almostUnwinnable
- -110 ;
-
- Value mg = mg_value(score);
- Value eg = eg_value(score);
-
- // Now apply the bonus: note that we find the attacking side by extracting the
- // sign of the midgame or endgame values, and that we carefully cap the bonus
- // so that the midgame and endgame scores do not change sign after the bonus.
- int u = ((mg > 0) - (mg < 0)) * std::clamp(complexity + 50, -abs(mg), 0);
- int v = ((eg > 0) - (eg < 0)) * std::max(complexity, -abs(eg));
-
- mg += u;
- eg += v;
-
- // Compute the scale factor for the winning side
- Color strongSide = eg > VALUE_DRAW ? WHITE : BLACK;
- int sf = me->scale_factor(pos, strongSide);
-
- // If scale factor is not already specific, scale up/down via general heuristics
- if (sf == SCALE_FACTOR_NORMAL)
- {
- if (pos.opposite_bishops())
- {
- // For pure opposite colored bishops endgames use scale factor
- // based on the number of passed pawns of the strong side.
- if ( pos.non_pawn_material(WHITE) == BishopValueMg
- && pos.non_pawn_material(BLACK) == BishopValueMg)
- sf = 18 + 4 * popcount(pe->passed_pawns(strongSide));
- // For every other opposite colored bishops endgames use scale factor
- // based on the number of all pieces of the strong side.
- else
- sf = 22 + 3 * pos.count<ALL_PIECES>(strongSide);
- }
- // For rook endgames with strong side not having overwhelming pawn number advantage
- // and its pawns being on one flank and weak side protecting its pieces with a king
- // use lower scale factor.
- else if ( pos.non_pawn_material(WHITE) == RookValueMg
- && pos.non_pawn_material(BLACK) == RookValueMg
- && pos.count<PAWN>(strongSide) - pos.count<PAWN>(~strongSide) <= 1
- && bool(KingSide & pos.pieces(strongSide, PAWN)) != bool(QueenSide & pos.pieces(strongSide, PAWN))
- && (attacks_bb<KING>(pos.square<KING>(~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<QUEEN>() == 1)
- sf = 37 + 3 * (pos.count<QUEEN>(WHITE) == 1 ? pos.count<BISHOP>(BLACK) + pos.count<KNIGHT>(BLACK)
- : pos.count<BISHOP>(WHITE) + pos.count<KNIGHT>(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<PAWN>(strongSide)) - 4 * !pawnsOnBothFlanks;
-
- // Reduce scale factor in case of pawns being on a single flank
- 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;
-
- if constexpr (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 Value(v);
- }
-
-
- // Evaluation::value() is the main function of the class. It computes the various
- // parts of the evaluation and returns the value of the position from the point
- // of view of the side to move.
-
- template<Tracing T>
- Value Evaluation<T>::value() {
-
- assert(!pos.checkers());
-
- // Probe the material hash table
- me = Material::probe(pos);
-
- // If we have a specialized evaluation function for the current material
- // configuration, call it and return.
- if (me->specialized_eval_exists())
- return me->evaluate(pos);
-
- // Initialize score by reading the incrementally updated scores included in
- // the position object (material + piece square tables) and the material
- // imbalance. Score is computed internally from the white point of view.
- Score score = pos.psq_score() + me->imbalance() + pos.this_thread()->trend;
-
- // 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)) > lazyThreshold + pos.non_pawn_material() / 32;
- };
-
- if (lazy_skip(LazyThreshold1))
- goto make_v;
-
- // Main evaluation begins here
- initialize<WHITE>();
- initialize<BLACK>();
-
- // Pieces evaluated first (also populates attackedBy, attackedBy2).
- // Note that the order of evaluation of the terms is left unspecified.
- score += pieces<WHITE, KNIGHT>() - pieces<BLACK, KNIGHT>()
- + pieces<WHITE, BISHOP>() - pieces<BLACK, BISHOP>()
- + pieces<WHITE, ROOK >() - pieces<BLACK, ROOK >()
- + pieces<WHITE, QUEEN >() - pieces<BLACK, QUEEN >();
-
- score += mobility[WHITE] - mobility[BLACK];
-
- // More complex interactions that require fully populated attack bitboards
- score += king< WHITE>() - king< BLACK>()
- + passed< WHITE>() - passed< BLACK>();
+ int nnueComplexity;
+ Value nnue = NNUE::evaluate(pos, true, &nnueComplexity);
- if (lazy_skip(LazyThreshold2))
- goto make_v;
+ Value optimism = pos.this_thread()->optimism[stm];
- score += threats<WHITE>() - threats<BLACK>()
- + space< WHITE>() - space< BLACK>();
+ // Blend optimism and eval with nnue complexity and material imbalance
+ optimism += optimism * (nnueComplexity + std::abs(simpleEval - nnue)) / 512;
+ nnue -= nnue * (nnueComplexity + std::abs(simpleEval - nnue)) / 32768;
-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 constexpr (T)
- {
- Trace::add(MATERIAL, pos.psq_score());
- Trace::add(IMBALANCE, me->imbalance());
- Trace::add(PAWN, pe->pawn_score(WHITE), pe->pawn_score(BLACK));
- Trace::add(MOBILITY, mobility[WHITE], mobility[BLACK]);
+ int npm = pos.non_pawn_material() / 64;
+ v = (nnue * (915 + npm + 9 * pos.count<PAWN>()) + optimism * (154 + npm)) / 1024;
}
- // Evaluation grain
- v = (v / 16) * 16;
+ // Damp down the evaluation linearly when shuffling
+ v = v * (200 - shuffling) / 214;
- // Side to move point of view
- v = (pos.side_to_move() == WHITE ? v : -v);
+ // 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;
- }
-
-
- /// Fisher Random Chess: correction for cornered bishops, to fix chess960 play with NNUE
-
- Value fix_FRC(const Position& pos) {
-
- constexpr Bitboard Corners = 1ULL << SQ_A1 | 1ULL << SQ_H1 | 1ULL << SQ_A8 | 1ULL << SQ_H8;
-
- if (!(pos.pieces(BISHOP) & Corners))
- return VALUE_ZERO;
-
- int correction = 0;
-
- if ( pos.piece_on(SQ_A1) == W_BISHOP
- && pos.piece_on(SQ_B2) == W_PAWN)
- correction -= CorneredBishop;
-
- if ( pos.piece_on(SQ_H1) == W_BISHOP
- && pos.piece_on(SQ_G2) == W_PAWN)
- correction -= CorneredBishop;
-
- if ( pos.piece_on(SQ_A8) == B_BISHOP
- && pos.piece_on(SQ_B7) == B_PAWN)
- correction += CorneredBishop;
-
- if ( pos.piece_on(SQ_H8) == B_BISHOP
- && pos.piece_on(SQ_G7) == B_PAWN)
- correction += CorneredBishop;
-
- return pos.side_to_move() == WHITE ? Value(5 * correction)
- : -Value(5 * correction);
- }
-
-} // 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) {
-
- Value v;
-
- if (!useNNUE)
- v = Evaluation<NO_TRACE>(pos).value();
- else
- {
- // Scale and shift NNUE for compatibility with search and classical evaluation
- auto adjusted_NNUE = [&]()
- {
- int scale = 883
- + 32 * pos.count<PAWN>()
- + 32 * pos.non_pawn_material() / 1024;
-
- Value nnue = NNUE::evaluate(pos, true) * scale / 1024;
-
- if (pos.is_chess960())
- nnue += fix_FRC(pos);
-
- return nnue;
- };
-
- // If there is PSQ imbalance we use the classical eval, but we switch to
- // NNUE eval faster when shuffling or if the material on the board is high.
- int r50 = pos.rule50_count();
- Value psq = Value(abs(eg_value(pos.psq_score())));
- bool classical = psq * 5 > (850 + pos.non_pawn_material() / 64) * (5 + r50);
-
- v = classical ? Evaluation<NO_TRACE>(pos).value() // classical
- : adjusted_NNUE(); // 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
-
+// Like evaluate(), but instead of returning a value, it returns
+// a string (suitable for outputting to stdout) that contains the detailed
+// descriptions and values of each evaluation term. Useful for debugging.
+// Trace scores are from white's point of view
std::string Eval::trace(Position& pos) {
- if (pos.checkers())
- 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()->trend = SCORE_ZERO; // Reset any dynamic contempt
-
- v = Evaluation<TRACE>(pos).value();
+ if (pos.checkers())
+ return "Final evaluation: none (in check)";
- ss << std::showpoint << std::noshowpos << std::fixed << std::setprecision(2)
- << " Contributing terms for the classical eval:\n"
- << "+------------+-------------+-------------+-------------+\n"
- << "| 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)
- << "+------------+-------------+-------------+-------------+\n";
+ // Reset any global variable used in eval
+ pos.this_thread()->bestValue = VALUE_ZERO;
+ pos.this_thread()->rootSimpleEval = VALUE_ZERO;
+ pos.this_thread()->optimism[WHITE] = VALUE_ZERO;
+ pos.this_thread()->optimism[BLACK] = VALUE_ZERO;
- if (Eval::useNNUE)
- ss << '\n' << NNUE::trace(pos) << '\n';
+ std::stringstream ss;
+ ss << std::showpoint << std::noshowpos << std::fixed << std::setprecision(2);
+ ss << '\n' << NNUE::trace(pos) << '\n';
- ss << std::showpoint << std::showpos << std::fixed << std::setprecision(2) << std::setw(15);
+ ss << std::showpoint << std::showpos << std::fixed << std::setprecision(2) << std::setw(15);
- v = pos.side_to_move() == WHITE ? v : -v;
- ss << "\nClassical evaluation " << to_cp(v) << " (white side)\n";
- if (Eval::useNNUE)
- {
- v = NNUE::evaluate(pos, false);
- v = pos.side_to_move() == WHITE ? v : -v;
- ss << "NNUE evaluation " << to_cp(v) << " (white side)\n";
- }
+ Value v;
+ v = NNUE::evaluate(pos, false);
+ v = pos.side_to_move() == WHITE ? v : -v;
+ ss << "NNUE evaluation " << 0.01 * UCI::to_cp(v) << " (white side)\n";
- v = evaluate(pos);
- v = pos.side_to_move() == WHITE ? v : -v;
- ss << "Final evaluation " << to_cp(v) << " (white side)";
- if (Eval::useNNUE)
- ss << " [with scaled NNUE, hybrid, ...]";
- ss << "\n";
+ v = evaluate(pos);
+ v = pos.side_to_move() == WHITE ? v : -v;
+ ss << "Final evaluation " << 0.01 * UCI::to_cp(v) << " (white side)";
+ ss << " [with scaled NNUE, ...]";
+ ss << "\n";
- return ss.str();
+ return ss.str();
}
-} // namespace Stockfish
+} // namespace Stockfish
projects / stockfish / blobdiff