mirror of
https://github.com/sockspls/badfish
synced 2025-04-30 16:53:09 +00:00
29c1e072b6
further simplification after https://github.com/official-stockfish/Stockfish/pull/4377 STC https://tests.stockfishchess.org/tests/view/63e02a3773223e7f52ad8190 LLR: 2.97 (-2.94,2.94) <-1.75,0.25> Total: 359072 W: 94605 L: 94733 D: 169734 Ptnml(0-2): 994, 39874, 97958, 39686, 1024 LTC https://tests.stockfishchess.org/tests/view/63e3fd12b5f425d71f77002a LLR: 2.96 (-2.94,2.94) <-1.75,0.25> Total: 248424 W: 66020 L: 66030 D: 116374 Ptnml(0-2): 113, 24653, 74689, 24645, 112 closes https://github.com/official-stockfish/Stockfish/pull/4390 bench: 4098325
1170 lines
45 KiB
C++
1170 lines
45 KiB
C++
/*
|
|
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
|
|
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
|
|
the Free Software Foundation, either version 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
Stockfish is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#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 (const 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));
|
|
(void) gEmbeddedNNUEEnd; // Silence warning on unused variable
|
|
|
|
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 {
|
|
|
|
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];
|
|
|
|
static double to_cp(Value v) { return double(v) / UCI::NormalizeToPawnValue; }
|
|
|
|
static void add(int idx, Color c, Score s) {
|
|
scores[idx][c] = s;
|
|
}
|
|
|
|
static void add(int idx, Score w, Score b = SCORE_ZERO) {
|
|
scores[idx][WHITE] = w;
|
|
scores[idx][BLACK] = b;
|
|
}
|
|
|
|
static 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;
|
|
}
|
|
|
|
static 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(3631);
|
|
constexpr Value LazyThreshold2 = Value(2084);
|
|
constexpr Value SpaceThreshold = Value(11551);
|
|
|
|
// KingAttackWeights[PieceType] contains king attack weights by piece type
|
|
constexpr int KingAttackWeights[PIECE_TYPE_NB] = { 0, 0, 76, 46, 45, 14 };
|
|
|
|
// 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] = {
|
|
{}, {}, {805, 1292}, {650, 984}, {1071, 1886}, {730, 1128}
|
|
};
|
|
|
|
#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, 7), S(3, 7)
|
|
};
|
|
|
|
// KingProtector[knight/bishop] contains penalty for each distance unit to own king
|
|
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(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(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(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(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(36, 71), S(44, 59), S(0, 39), S(60, 39)
|
|
};
|
|
|
|
constexpr Value CorneredBishop = Value(50);
|
|
|
|
// Assorted bonuses and penalties
|
|
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( 72, 40);
|
|
constexpr Score KnightOnQueen = S( 16, 11);
|
|
constexpr Score LongDiagonalBishop = S( 45, 0);
|
|
constexpr Score MinorBehindPawn = S( 18, 3);
|
|
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( 62, 21);
|
|
constexpr Score ThreatByKing = S( 24, 87);
|
|
constexpr Score ThreatByPawnPush = S( 48, 39);
|
|
constexpr Score ThreatBySafePawn = S(167, 99);
|
|
constexpr Score TrappedRook = S( 55, 13);
|
|
constexpr Score WeakQueenProtection = S( 14, 0);
|
|
constexpr Score WeakQueen = S( 57, 19);
|
|
|
|
|
|
#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;
|
|
[[maybe_unused]] constexpr Direction Down = -pawn_push(Us);
|
|
[[maybe_unused]] 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 constexpr (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]);
|
|
|
|
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];
|
|
|
|
// 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)];
|
|
|
|
else
|
|
unsafeChecks |= b2 & attackedBy[Them][BISHOP];
|
|
|
|
// Enemy knights checks
|
|
knightChecks = attacks_bb<KNIGHT>(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<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();
|
|
|
|
// 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
|
|
+ std::abs(pos.this_thread()->bestValue) * 5 / 4
|
|
+ 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>();
|
|
|
|
if (lazy_skip(LazyThreshold2))
|
|
goto make_v;
|
|
|
|
score += threats<WHITE>() - threats<BLACK>()
|
|
+ space< WHITE>() - space< BLACK>();
|
|
|
|
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]);
|
|
}
|
|
|
|
// Evaluation grain
|
|
v = (v / 16) * 16;
|
|
|
|
// Side to move point of view
|
|
v = (pos.side_to_move() == WHITE ? v : -v);
|
|
|
|
return v;
|
|
}
|
|
|
|
} // 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, int* complexity) {
|
|
|
|
Value v;
|
|
Value psq = pos.psq_eg_stm();
|
|
|
|
// We use the much less accurate but faster Classical eval when the NNUE
|
|
// option is set to false. Otherwise we use the NNUE eval unless the
|
|
// PSQ advantage is decisive and several pieces remain. (~3 Elo)
|
|
bool useClassical = !useNNUE || (pos.count<ALL_PIECES>() > 7 && abs(psq) > 1781);
|
|
|
|
if (useClassical)
|
|
v = Evaluation<NO_TRACE>(pos).value();
|
|
else
|
|
{
|
|
int nnueComplexity;
|
|
int scale = 1076 + 96 * pos.non_pawn_material() / 5120;
|
|
|
|
Color stm = pos.side_to_move();
|
|
Value optimism = pos.this_thread()->optimism[stm];
|
|
|
|
Value nnue = NNUE::evaluate(pos, true, &nnueComplexity);
|
|
|
|
// Blend nnue complexity with (semi)classical complexity
|
|
nnueComplexity = ( 406 * nnueComplexity
|
|
+ (424 + optimism) * abs(psq - nnue)
|
|
) / 1024;
|
|
|
|
// Return hybrid NNUE complexity to caller
|
|
if (complexity)
|
|
*complexity = nnueComplexity;
|
|
|
|
optimism = optimism * (272 + nnueComplexity) / 256;
|
|
v = (nnue * scale + optimism * (scale - 748)) / 1024;
|
|
}
|
|
|
|
// Damp down the evaluation linearly when shuffling
|
|
v = v * (200 - pos.rule50_count()) / 214;
|
|
|
|
// 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);
|
|
|
|
// When not using NNUE, return classical complexity to caller
|
|
if (complexity && useClassical)
|
|
*complexity = abs(v - psq);
|
|
|
|
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(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));
|
|
|
|
// Reset any global variable used in eval
|
|
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();
|
|
|
|
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";
|
|
|
|
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
|