/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
- Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
+ Copyright (C) 2004-2022 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
namespace Eval {
bool useNNUE;
- string eval_file_loaded = "None";
+ 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"
return;
string eval_file = string(Options["EvalFile"]);
+ if (eval_file.empty())
+ eval_file = EvalFileDefaultName;
#if defined(DEFAULT_NNUE_DIRECTORY)
#define stringify2(x) #x
#endif
for (string directory : dirs)
- if (eval_file_loaded != eval_file)
+ if (currentEvalFileName != eval_file)
{
if (directory != "<internal>")
{
ifstream stream(directory + eval_file, ios::binary);
if (load_eval(eval_file, stream))
- eval_file_loaded = eval_file;
+ currentEvalFileName = eval_file;
}
if (directory == "<internal>" && eval_file == EvalFileDefaultName)
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))
- eval_file_loaded = eval_file;
+ currentEvalFileName = eval_file;
}
}
}
void NNUE::verify() {
string eval_file = string(Options["EvalFile"]);
+ if (eval_file.empty())
+ eval_file = EvalFileDefaultName;
- if (useNNUE && eval_file_loaded != eval_file)
+ if (useNNUE && currentEvalFileName != 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 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.";
sync_cout << "info string ERROR: " << msg1 << sync_endl;
namespace {
// Threshold for lazy and space evaluation
- constexpr Value LazyThreshold1 = Value(3130);
- constexpr Value LazyThreshold2 = Value(2204);
+ constexpr Value LazyThreshold1 = Value(3631);
+ constexpr Value LazyThreshold2 = Value(2084);
constexpr Value SpaceThreshold = Value(11551);
// KingAttackWeights[PieceType] contains king attack weights by piece type
// 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)
+ S(3, 8), S(3, 9), S(2, 7), S(3, 7)
};
// KingProtector[knight/bishop] contains penalty for each distance unit to own king
- constexpr Score KingProtector[] = { S(8, 9), S(6, 9) };
+ constexpr Score KingProtector[] = { S(9, 9), S(7, 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) };
+ constexpr Score Outpost[] = { S(54, 34), S(31, 25) };
// 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)
+ S(0, 0), S(2, 38), S(15, 36), S(22, 50), S(64, 81), S(166, 184), S(284, 269)
};
constexpr Score RookOnClosedFile = S(10, 5);
- constexpr Score RookOnOpenFile[] = { S(19, 6), S(47, 26) };
+ constexpr Score RookOnOpenFile[] = { S(18, 8), S(49, 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)
+ S(0, 0), S(6, 37), S(64, 50), S(82, 57), S(103, 130), S(81, 163)
};
constexpr Score ThreatByRook[PIECE_TYPE_NB] = {
- S(0, 0), S(3, 44), S(37, 68), S(42, 60), S(0, 39), S(58, 43)
+ S(0, 0), S(3, 44), S(36, 71), S(44, 59), S(0, 39), S(60, 39)
};
constexpr Value CorneredBishop = Value(50);
// Assorted bonuses and penalties
- constexpr Score UncontestedOutpost = S( 1, 10);
+ constexpr Score UncontestedOutpost = S( 0, 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 Hanging = S( 72, 40);
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 PassedFile = S( 13, 8);
+ constexpr Score PawnlessFlank = S( 19, 97);
+ constexpr Score ReachableOutpost = S( 33, 19);
+ constexpr Score RestrictedPiece = S( 6, 7);
constexpr Score RookOnKingRing = S( 16, 0);
- constexpr Score SliderOnQueen = S( 60, 18);
- constexpr Score ThreatByKing = S( 24, 89);
+ constexpr Score SliderOnQueen = S( 62, 21);
+ constexpr Score ThreatByKing = S( 24, 87);
constexpr Score ThreatByPawnPush = S( 48, 39);
- constexpr Score ThreatBySafePawn = S(173, 94);
+ constexpr Score ThreatBySafePawn = S(167, 99);
constexpr Score TrappedRook = S( 55, 13);
constexpr Score WeakQueenProtection = S( 14, 0);
- constexpr Score WeakQueen = S( 56, 15);
+ constexpr Score WeakQueen = S( 57, 19);
#undef S
// 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;
+ return abs(mg_value(score) + eg_value(score)) > lazyThreshold
+ + std::abs(pos.this_thread()->bestValue) * 5 / 4
+ + pos.non_pawn_material() / 32;
};
if (lazy_skip(LazyThreshold1))
if ( pos.piece_on(SQ_A1) == W_BISHOP
&& pos.piece_on(SQ_B2) == W_PAWN)
- correction += !pos.empty(SQ_B3) ? -CorneredBishop * 4
- : -CorneredBishop * 3;
+ correction -= CorneredBishop;
if ( pos.piece_on(SQ_H1) == W_BISHOP
&& pos.piece_on(SQ_G2) == W_PAWN)
- correction += !pos.empty(SQ_G3) ? -CorneredBishop * 4
- : -CorneredBishop * 3;
+ correction -= CorneredBishop;
if ( pos.piece_on(SQ_A8) == B_BISHOP
&& pos.piece_on(SQ_B7) == B_PAWN)
- correction += !pos.empty(SQ_B6) ? CorneredBishop * 4
- : CorneredBishop * 3;
+ correction += CorneredBishop;
if ( pos.piece_on(SQ_H8) == B_BISHOP
&& pos.piece_on(SQ_G7) == B_PAWN)
- correction += !pos.empty(SQ_G6) ? CorneredBishop * 4
- : CorneredBishop * 3;
+ correction += CorneredBishop;
- return pos.side_to_move() == WHITE ? Value(correction)
- : -Value(correction);
+ return pos.side_to_move() == WHITE ? Value(3 * correction)
+ : -Value(3 * correction);
}
} // namespace Eval
Value Eval::evaluate(const Position& pos) {
Value v;
+ bool useClassical = false;
- if (!Eval::useNNUE)
- v = Evaluation<NO_TRACE>(pos).value();
- else
+ // Deciding between classical and NNUE eval (~10 Elo): for high PSQ imbalance we use classical,
+ // but we switch to NNUE during long shuffling or with high material on the board.
+ if ( !useNNUE
+ || abs(eg_value(pos.psq_score())) * 5 > (856 + pos.non_pawn_material() / 64) * (5 + pos.rule50_count()))
{
- // Scale and shift NNUE for compatibility with search and classical evaluation
- auto adjusted_NNUE = [&]()
- {
- int scale = 903
- + 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 > (750 + pos.non_pawn_material() / 64) * (5 + r50);
+ v = Evaluation<NO_TRACE>(pos).value(); // classical
+ useClassical = abs(v) >= 297;
+ }
- v = classical ? Evaluation<NO_TRACE>(pos).value() // classical
- : adjusted_NNUE(); // NNUE
+ // If result of a classical evaluation is much lower than threshold fall back to NNUE
+ if (useNNUE && !useClassical)
+ {
+ Value nnue = NNUE::evaluate(pos, true); // NNUE
+ int scale = 1036 + 20 * pos.non_pawn_material() / 1024;
+ Color stm = pos.side_to_move();
+ Value optimism = pos.this_thread()->optimism[stm];
+ Value psq = (stm == WHITE ? 1 : -1) * eg_value(pos.psq_score());
+ int complexity = 35 * abs(nnue - psq) / 256;
+
+ optimism = optimism * (44 + complexity) / 31;
+ v = (nnue + optimism) * scale / 1024 - optimism;
+
+ if (pos.is_chess960())
+ v += fix_FRC(pos);
}
// Damp down the evaluation linearly when shuffling
- v = v * (100 - pos.rule50_count()) / 100;
+ v = v * (207 - pos.rule50_count()) / 207;
// 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);
std::memset(scores, 0, sizeof(scores));
- pos.this_thread()->trend = SCORE_ZERO; // Reset any dynamic contempt
+ // Reset any global variable used in eval
+ pos.this_thread()->trend = SCORE_ZERO;
+ pos.this_thread()->bestValue = VALUE_ZERO;
+ pos.this_thread()->optimism[WHITE] = VALUE_ZERO;
+ pos.this_thread()->optimism[BLACK] = VALUE_ZERO;
v = Evaluation<TRACE>(pos).value();
projects / stockfish / blobdiff