/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
- Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
- Copyright (C) 2015-2020 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+ Copyright (C) 2004-2021 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
#include <algorithm>
#include <cassert>
+#include <cstdlib>
#include <cstring> // For std::memset
+#include <fstream>
#include <iomanip>
#include <sstream>
+#include <iostream>
+#include <streambuf>
+#include <vector>
#include "bitboard.h"
#include "evaluate.h"
#include "material.h"
+#include "misc.h"
#include "pawns.h"
#include "thread.h"
+#include "timeman.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).
+// This macro invocation will declare the following three variables
+// const unsigned char gEmbeddedNNUEData[]; // a pointer to the embedded data
+// const unsigned char *const gEmbeddedNNUEEnd; // a marker to the end
+// const unsigned int gEmbeddedNNUESize; // the size of the embedded file
+// Note that this does not work in Microsoft Visual Studio.
+#if !defined(_MSC_VER) && !defined(NNUE_EMBEDDING_OFF)
+ INCBIN(EmbeddedNNUE, EvalFileDefaultName);
+#else
+ const unsigned char gEmbeddedNNUEData[1] = {0x0};
+ const unsigned char *const gEmbeddedNNUEEnd = &gEmbeddedNNUEData[1];
+ const unsigned int gEmbeddedNNUESize = 1;
+#endif
+
+
+using namespace std;
+
+namespace Stockfish {
+
+namespace Eval {
+
+ bool useNNUE;
+ 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.
+
+ void NNUE::init() {
+
+ useNNUE = Options["Use NNUE"];
+ if (!useNNUE)
+ return;
+
+ string eval_file = 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
+
+ for (string directory : dirs)
+ if (currentEvalFileName != eval_file)
+ {
+ if (directory != "<internal>")
+ {
+ ifstream stream(directory + eval_file, ios::binary);
+ if (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); }
+ };
+
+ MemoryBuffer buffer(const_cast<char*>(reinterpret_cast<const char*>(gEmbeddedNNUEData)),
+ size_t(gEmbeddedNNUESize));
+
+ istream stream(&buffer);
+ if (load_eval(eval_file, stream))
+ currentEvalFileName = eval_file;
+ }
+ }
+ }
+
+ /// NNUE::verify() verifies that the last net used was loaded successfully
+ void NNUE::verify() {
+
+ string eval_file = string(Options["EvalFile"]);
+ if (eval_file.empty())
+ eval_file = EvalFileDefaultName;
+
+ if (useNNUE && 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.";
+
+ sync_cout << "info string ERROR: " << msg1 << sync_endl;
+ sync_cout << "info string ERROR: " << msg2 << sync_endl;
+ sync_cout << "info string ERROR: " << msg3 << sync_endl;
+ sync_cout << "info string ERROR: " << msg4 << sync_endl;
+ sync_cout << "info string ERROR: " << msg5 << sync_endl;
+
+ exit(EXIT_FAILURE);
+ }
+
+ if (useNNUE)
+ sync_cout << "info string NNUE evaluation using " << eval_file << " enabled" << sync_endl;
+ else
+ sync_cout << "info string classical evaluation enabled" << sync_endl;
+ }
+}
namespace Trace {
else
os << scores[t][WHITE] << " | " << scores[t][BLACK];
- os << " | " << scores[t][WHITE] - scores[t][BLACK] << "\n";
+ os << " | " << scores[t][WHITE] - scores[t][BLACK] << " |\n";
return os;
}
}
namespace {
// Threshold for lazy and space evaluation
- constexpr Value LazyThreshold1 = Value(1400);
- constexpr Value LazyThreshold2 = Value(1300);
- constexpr Value SpaceThreshold = Value(12222);
+ 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] = {
- {}, {}, {792, 1283}, {645, 967}, {1084, 1897}, {772, 1119}
+ {}, {}, {803, 1292}, {639, 974}, {1087, 1878}, {759, 1132}
};
#define S(mg, eg) make_score(mg, eg)
// MobilityBonus[PieceType-2][attacked] contains bonuses for middle and end game,
// indexed by piece type and number of attacked squares in the mobility area.
constexpr Score MobilityBonus[][32] = {
- { S(-62,-81), S(-53,-56), S(-12,-31), S( -4,-16), S( 3, 5), S( 13, 11), // Knight
- S( 22, 17), S( 28, 20), S( 33, 25) },
- { S(-48,-59), S(-20,-23), S( 16, -3), S( 26, 13), S( 38, 24), S( 51, 42), // Bishop
- S( 55, 54), S( 63, 57), S( 63, 65), S( 68, 73), S( 81, 78), S( 81, 86),
- S( 91, 88), S( 98, 97) },
- { S(-60,-78), S(-20,-17), S( 2, 23), S( 3, 39), S( 3, 70), S( 11, 99), // Rook
- S( 22,103), S( 31,121), S( 40,134), S( 40,139), S( 41,158), S( 48,164),
- S( 57,168), S( 57,169), S( 62,172) },
- { S(-30,-48), S(-12,-30), S( -8, -7), S( -9, 19), S( 20, 40), S( 23, 55), // Queen
- S( 23, 59), S( 35, 75), S( 38, 78), S( 53, 96), S( 64, 96), S( 65,100),
- S( 65,121), S( 66,127), S( 67,131), S( 67,133), S( 72,136), S( 72,141),
- S( 77,147), S( 79,150), S( 93,151), S(108,168), S(108,168), S(108,171),
- S(110,182), S(114,182), S(114,192), S(116,219) }
+ { 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
// 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, 36), S(30, 23) };
+ 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(10, 28), S(17, 33), S(15, 41), S(62, 72), S(168, 177), S(276, 260)
+ S(0, 0), S(7, 27), S(16, 32), S(17, 40), S(64, 71), S(170, 174), S(278, 262)
};
- // RookOnFile[semiopen/open] contains bonuses for each rook when there is
- // no (friendly) pawn on the rook file.
- constexpr Score RookOnFile[] = { S(19, 7), S(48, 29) };
+ 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(57, 41), S(77, 56), S(88, 119), S(79, 161)
+ S(0, 0), S(5, 32), S(55, 41), S(77, 56), S(89, 119), S(79, 162)
};
constexpr Score ThreatByRook[PIECE_TYPE_NB] = {
- S(0, 0), S(3, 46), S(37, 68), S(42, 60), S(0, 38), S(58, 41)
+ 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 BadOutpost = S( -7, 36);
+ constexpr Score UncontestedOutpost = S( 1, 10);
constexpr Score BishopOnKingRing = S( 24, 0);
- constexpr Score BishopPawns = S( 3, 7);
constexpr Score BishopXRayPawns = S( 4, 5);
- constexpr Score CorneredBishop = S( 50, 50);
constexpr Score FlankAttacks = S( 8, 0);
constexpr Score Hanging = S( 69, 36);
constexpr Score KnightOnQueen = S( 16, 11);
constexpr Score MinorBehindPawn = S( 18, 3);
constexpr Score PassedFile = S( 11, 8);
constexpr Score PawnlessFlank = S( 17, 95);
- constexpr Score QueenInfiltration = S( -2, 14);
constexpr Score ReachableOutpost = S( 31, 22);
constexpr Score RestrictedPiece = S( 7, 7);
constexpr Score RookOnKingRing = S( 16, 0);
- constexpr Score RookOnQueenFile = S( 6, 11);
constexpr Score SliderOnQueen = S( 60, 18);
constexpr Score ThreatByKing = S( 24, 89);
constexpr Score ThreatByPawnPush = S( 48, 39);
attackedBy2[Us] = dblAttackByPawn | (attackedBy[Us][KING] & attackedBy[Us][PAWN]);
// Init our king safety tables
- Square s = make_square(Utility::clamp(file_of(ksq), FILE_B, FILE_G),
- Utility::clamp(rank_of(ksq), RANK_2, RANK_7));
+ 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));
constexpr Direction Down = -pawn_push(Us);
constexpr Bitboard OutpostRanks = (Us == WHITE ? Rank4BB | Rank5BB | Rank6BB
: Rank5BB | Rank4BB | Rank3BB);
- const Square* pl = pos.squares<Pt>(Us);
-
+ Bitboard b1 = pos.pieces(Us, Pt);
Bitboard b, bb;
Score score = SCORE_ZERO;
attackedBy[Us][Pt] = 0;
- for (Square s = *pl; s != SQ_NONE; s = *++pl)
+ 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))
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
- // Reduced bonus for knights (BadOutpost) if few relevant targets
- bb = OutpostRanks & attackedBy[Us][PAWN] & ~pe->pawn_attacks_span(Them);
+ // 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 += BadOutpost;
+ 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))
// Penalty if the piece is far from the king
score -= KingProtector[Pt == BISHOP] * distance(pos.square<KING>(Us), s);
- if (Pt == BISHOP)
+ 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 * pos.pawns_on_same_color_squares(Us, s)
+ 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
{
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;
+ score -= !pos.empty(s + d + pawn_push(Us)) ? 4 * make_score(CorneredBishop, CorneredBishop)
+ : 3 * make_score(CorneredBishop, CorneredBishop);
}
}
}
- if (Pt == ROOK)
+ if constexpr (Pt == ROOK)
{
- // Bonus for rook on the same file as a queen
- if (file_bb(s) & pos.pieces(QUEEN))
- score += RookOnQueenFile;
-
- // Bonus for rook on an open or semi-open file
+ // Bonuses for rook on a (semi-)open or closed file
if (pos.is_on_semiopen_file(Us, s))
- score += RookOnFile[pos.is_on_semiopen_file(Them, s)];
-
- // Penalty when trapped by the king, even more if the king cannot castle
- else if (mob <= 3)
{
- File kf = file_of(pos.square<KING>(Us));
- if ((kf < FILE_E) == (file_of(s) < kf))
- score -= TrappedRook * (1 + !pos.castling_rights(Us));
+ score += RookOnOpenFile[pos.is_on_semiopen_file(Them, s)];
+ }
+ else
+ {
+ // If our pawn on this file is blocked, increase penalty
+ if ( pos.pieces(Us, PAWN)
+ & shift<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 (Pt == QUEEN)
+ 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;
-
- // Bonus for queen on weak square in enemy camp
- if (relative_rank(Us, s) > RANK_4 && (~pe->pawn_attacks_span(Them) & s))
- score += QueenInfiltration;
}
}
- if (T)
+ if constexpr (T)
Trace::add(Pt, Us, score);
return score;
int kingFlankAttack = popcount(b1) + popcount(b2);
int kingFlankDefense = popcount(b3);
- kingDanger += kingAttackersCount[Them] * kingAttackersWeight[Them]
- + 185 * popcount(kingRing[Us] & weak)
- + 148 * popcount(unsafeChecks)
- + 98 * popcount(pos.blockers_for_king(Us))
- + 69 * kingAttacksCount[Them]
- + 3 * kingFlankAttack * kingFlankAttack / 8
- + mg_value(mobility[Them] - mobility[Us])
- - 873 * !pos.count<QUEEN>(Them)
- - 100 * bool(attackedBy[Us][KNIGHT] & attackedBy[Us][KING])
- - 6 * mg_value(score) / 8
- - 4 * kingFlankDefense
- + 37;
+ 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)
// Penalty if king flank is under attack, potentially moving toward the king
score -= FlankAttacks * kingFlankAttack;
- if (T)
+ if constexpr (T)
Trace::add(KING, Us, score);
return score;
{
b = (defended | weak) & (attackedBy[Us][KNIGHT] | attackedBy[Us][BISHOP]);
while (b)
- score += ThreatByMinor[type_of(pos.piece_on(pop_lsb(&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)))];
+ score += ThreatByRook[type_of(pos.piece_on(pop_lsb(b)))];
if (weak & attackedBy[Us][KING])
score += ThreatByKing;
// 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] & ~stronglyProtected;
+ safe = mobilityArea[Us]
+ & ~pos.pieces(Us, PAWN)
+ & ~stronglyProtected;
b = attackedBy[Us][KNIGHT] & attacks_bb<KNIGHT>(s);
- score += KnightOnQueen * popcount(b & safe);
+ 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]);
+ score += SliderOnQueen * popcount(b & safe & attackedBy2[Us]) * (1 + queenImbalance);
}
- if (T)
+ if constexpr (T)
Trace::add(THREAT, Us, score);
return score;
while (b)
{
- Square s = pop_lsb(&b);
+ Square s = pop_lsb(b);
assert(!(pos.pieces(Them, PAWN) & forward_file_bb(Us, s + Up)));
Square blockSq = s + Up;
// Adjust bonus based on the king's proximity
- bonus += make_score(0, ( (king_proximity(Them, blockSq) * 19) / 4
- - king_proximity(Us, blockSq) * 2) * w);
+ bonus += make_score(0, ( king_proximity(Them, blockSq) * 19 / 4
+ - king_proximity(Us, blockSq) * 2) * w);
// If blockSq is not the queening square then consider also a second push
if (r != RANK_7)
bb = forward_file_bb(Them, s) & pos.pieces(ROOK, QUEEN);
if (!(pos.pieces(Them) & bb))
- unsafeSquares &= attackedBy[Them][ALL_PIECES];
+ unsafeSquares &= attackedBy[Them][ALL_PIECES] | pos.pieces(Them);
- // If there are no enemy attacks on passed pawn span, assign a big bonus.
+ // 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 ? 35 :
- !(unsafeSquares & squaresToQueen) ? 20 :
- !(unsafeSquares & blockSq) ? 9 :
+ 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
score += bonus - PassedFile * edge_distance(file_of(s));
}
- if (T)
+ 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 4 central files
+ // 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.
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 (T)
+ if constexpr (T)
Trace::add(SPACE, Us, score);
return score;
Value Evaluation<T>::winnable(Score score) const {
int outflanking = distance<File>(pos.square<KING>(WHITE), pos.square<KING>(BLACK))
- - distance<Rank>(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);
// Now apply the bonus: note that we find the attacking side by extracting the
// sign of the midgame or endgame values, and that we carefully cap the bonus
// so that the midgame and endgame scores do not change sign after the bonus.
- int u = ((mg > 0) - (mg < 0)) * Utility::clamp(complexity + 50, -abs(mg), 0);
+ int 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;
Color strongSide = eg > VALUE_DRAW ? WHITE : BLACK;
int sf = me->scale_factor(pos, strongSide);
- // If scale factor is not already specific, scale down via general heuristics
+ // 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));
+ 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
+ eg * int(PHASE_MIDGAME - me->game_phase()) * ScaleFactor(sf) / SCALE_FACTOR_NORMAL;
v /= PHASE_MIDGAME;
- if (T)
+ 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));
// 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;
+ Score score = pos.psq_score() + me->imbalance() + pos.this_thread()->trend;
// Probe the pawn hash table
pe = Pawns::probe(pos);
// 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;
+ return abs(mg_value(score) + eg_value(score)) > lazyThreshold + pos.non_pawn_material() / 32;
};
if (lazy_skip(LazyThreshold1))
Value v = winnable(score);
// In case of tracing add all remaining individual evaluation terms
- if (T)
+ if constexpr (T)
{
Trace::add(MATERIAL, pos.psq_score());
Trace::add(IMBALANCE, me->imbalance());
v = (v / 16) * 16;
// Side to move point of view
- v = (pos.side_to_move() == WHITE ? v : -v) + Tempo;
-
- // Damp down the evaluation linearly when shuffling
- v = v * (100 - pos.rule50_count()) / 100;
+ v = (pos.side_to_move() == WHITE ? v : -v);
return v;
}
-} // namespace
+
+ /// 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) {
- return Evaluation<NO_TRACE>(pos).value();
-}
+ Value v;
+
+ // Deciding between classical and NNUE eval: 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 > (850 + pos.non_pawn_material() / 64) * (5 + pos.rule50_count()))
+ v = Evaluation<NO_TRACE>(pos).value(); // classical
+ else
+ {
+ int scale = 883
+ + 32 * pos.count<PAWN>()
+ + 32 * pos.non_pawn_material() / 1024;
+
+ v = NNUE::evaluate(pos, true) * scale / 1024; // NNUE
+
+ if (pos.is_chess960())
+ v += fix_FRC(pos);
+ }
+
+ // Damp down the evaluation linearly when shuffling
+ v = v * (100 - pos.rule50_count()) / 100;
+
+ // Guarantee evaluation does not hit the tablebase range
+ v = std::clamp(v, VALUE_TB_LOSS_IN_MAX_PLY + 1, VALUE_TB_WIN_IN_MAX_PLY - 1);
+
+ return v;
+}
/// trace() is like evaluate(), but instead of returning a value, it returns
/// a string (suitable for outputting to stdout) that contains the detailed
/// descriptions and values of each evaluation term. Useful for debugging.
+/// Trace scores are from white's point of view
-std::string Eval::trace(const Position& pos) {
+std::string Eval::trace(Position& pos) {
if (pos.checkers())
- return "Total evaluation: none (in check)";
+ return "Final evaluation: none (in check)";
- std::memset(scores, 0, sizeof(scores));
+ std::stringstream ss;
+ ss << std::showpoint << std::noshowpos << std::fixed << std::setprecision(2);
- pos.this_thread()->contempt = SCORE_ZERO; // Reset any dynamic contempt
+ Value v;
- Value v = Evaluation<TRACE>(pos).value();
+ std::memset(scores, 0, sizeof(scores));
- v = pos.side_to_move() == WHITE ? v : -v; // Trace scores are from white's point of view
+ pos.this_thread()->trend = SCORE_ZERO; // Reset any dynamic contempt
+
+ v = Evaluation<TRACE>(pos).value();
- std::stringstream ss;
ss << std::showpoint << std::noshowpos << std::fixed << std::setprecision(2)
- << " Term | White | Black | Total \n"
- << " | MG EG | MG EG | MG EG \n"
- << " ------------+-------------+-------------+------------\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);
-
- ss << "\nFinal evaluation: " << to_cp(v) << " (white side)\n";
+ << " 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";
+
+ if (Eval::useNNUE)
+ ss << '\n' << NNUE::trace(pos) << '\n';
+
+ 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";
+ }
+
+ 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";
return ss.str();
}
+
+} // namespace Stockfish
projects / stockfish / blobdiff