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Merge remote-tracking branch 'upstream/master' into data_generation

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Tomasz Sobczyk
2021-04-18 19:45:46 +02:00
parent f1d4c1c896 a7ab92ec25
commit 08e255960d
61 changed files with 1444 additions and 1577 deletions
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src/evaluate.cpp
+137 -56
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@@ -1,6 +1,6 @@
/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2020 The Stockfish developers (see AUTHORS file)
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
@@ -122,7 +122,7 @@ namespace {
// BishopPawns[distance from edge] contains a file-dependent penalty for pawns on
// squares of the same color as our bishop.
constexpr Score BishopPawns[int(FILE_NB) / 2] = {
S(3, 8), S(3, 9), S(1, 8), S(3, 7)
S(3, 8), S(3, 9), S(2, 8), S(3, 8)
};
// KingProtector[knight/bishop] contains penalty for each distance unit to own king
@@ -130,16 +130,15 @@ namespace {
// Outpost[knight/bishop] contains bonuses for each knight or bishop occupying a
// pawn protected square on rank 4 to 6 which is also safe from a pawn attack.
constexpr Score Outpost[] = { S(56, 34), S(31, 23) };
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(9, 28), S(15, 31), S(17, 39), S(64, 70), S(171, 177), S(277, 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, 27) };
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
@@ -152,11 +151,12 @@ namespace {
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 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);
@@ -285,15 +285,16 @@ namespace {
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))
@@ -320,13 +321,12 @@ namespace {
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
// 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);
@@ -335,7 +335,7 @@ namespace {
&& 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))
@@ -348,7 +348,7 @@ namespace {
// 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
@@ -373,29 +373,40 @@ namespace {
{
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 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;
@@ -403,7 +414,7 @@ namespace {
score -= WeakQueen;
}
}
if (T)
if constexpr (T)
Trace::add(Pt, Us, score);
return score;
@@ -480,7 +491,7 @@ namespace {
int kingFlankDefense = popcount(b3);
kingDanger += kingAttackersCount[Them] * kingAttackersWeight[Them] // (~10 Elo)
+ 185 * popcount(kingRing[Us] & weak) // (~15 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)
@@ -503,7 +514,7 @@ namespace {
// 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;
@@ -542,11 +553,11 @@ namespace {
{
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;
@@ -604,7 +615,7 @@ namespace {
score += SliderOnQueen * popcount(b & safe & attackedBy2[Us]) * (1 + queenImbalance);
}
if (T)
if constexpr (T)
Trace::add(THREAT, Us, score);
return score;
@@ -644,7 +655,7 @@ namespace {
while (b)
{
Square s = pop_lsb(&b);
Square s = pop_lsb(b);
assert(!(pos.pieces(Them, PAWN) & forward_file_bb(Us, s + Up)));
@@ -674,14 +685,16 @@ namespace {
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
@@ -695,7 +708,7 @@ namespace {
score += bonus - PassedFile * edge_distance(file_of(s));
}
if (T)
if constexpr (T)
Trace::add(PASSED, Us, score);
return score;
@@ -730,11 +743,13 @@ namespace {
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;
@@ -749,7 +764,7 @@ namespace {
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);
@@ -791,24 +806,36 @@ namespace {
{
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;
}
@@ -817,7 +844,7 @@ namespace {
+ 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));
@@ -889,7 +916,7 @@ make_v:
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());
@@ -906,7 +933,43 @@ make_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 += !pos.empty(SQ_B3) ? -CorneredBishop * 4
: -CorneredBishop * 3;
if ( pos.piece_on(SQ_H1) == W_BISHOP
&& pos.piece_on(SQ_G2) == W_PAWN)
correction += !pos.empty(SQ_G3) ? -CorneredBishop * 4
: -CorneredBishop * 3;
if ( pos.piece_on(SQ_A8) == B_BISHOP
&& pos.piece_on(SQ_B7) == B_PAWN)
correction += !pos.empty(SQ_B6) ? CorneredBishop * 4
: CorneredBishop * 3;
if ( pos.piece_on(SQ_H8) == B_BISHOP
&& pos.piece_on(SQ_G7) == B_PAWN)
correction += !pos.empty(SQ_G6) ? CorneredBishop * 4
: CorneredBishop * 3;
return pos.side_to_move() == WHITE ? Value(correction)
: -Value(correction);
}
} // namespace Eval
/// evaluate() is the evaluator for the outer world. It returns a static
@@ -931,25 +994,41 @@ Value Eval::evaluate(const Position& pos) {
else
{
// Scale and shift NNUE for compatibility with search and classical evaluation
auto adjusted_NNUE = [&](){
int mat = pos.non_pawn_material() + PawnValueMg * pos.count<PAWN>();
return NNUE::evaluate(pos) * (720 + mat / 32) / 1024 + Tempo;
auto adjusted_NNUE = [&]()
{
int material = pos.non_pawn_material() + 4 * PawnValueMg * pos.count<PAWN>();
int scale = 580
+ material / 32
- 4 * pos.rule50_count();
Value nnue = NNUE::evaluate(pos) * scale / 1024 + Tempo;
if (pos.is_chess960())
nnue += fix_FRC(pos);
return nnue;
};
// If there is PSQ imbalance use classical eval, with small probability if it is small
// If there is PSQ imbalance we use the classical eval. We also introduce
// a small probability of using the classical eval when PSQ imbalance is small.
Value psq = Value(abs(eg_value(pos.psq_score())));
int r50 = 16 + pos.rule50_count();
bool largePsq = psq * 16 > (NNUEThreshold1 + pos.non_pawn_material() / 64) * r50;
bool classical = largePsq || (psq > PawnValueMg / 4 && !(pos.this_thread()->nodes & 0xB));
bool strongClassical = pos.non_pawn_material() < 2 * RookValueMg && pos.count<PAWN>() < 2;
// Use classical evaluation for really low piece endgames.
// One critical case is the draw for bishop + A/H file pawn vs naked king.
bool lowPieceEndgame = pos.non_pawn_material() == BishopValueMg
|| (pos.non_pawn_material() < 2 * RookValueMg && pos.count<PAWN>() < 2);
v = classical || strongClassical ? Evaluation<NO_TRACE>(pos).value() : adjusted_NNUE();
v = classical || lowPieceEndgame ? Evaluation<NO_TRACE>(pos).value()
: adjusted_NNUE();
// If the classical eval is small and imbalance large, use NNUE nevertheless.
// For the case of opposite colored bishops, switch to NNUE eval with
// small probability if the classical eval is less than the threshold.
if ( largePsq && !strongClassical
// For the case of opposite colored bishops, switch to NNUE eval with small
// probability if the classical eval is less than the threshold.
if ( largePsq
&& !lowPieceEndgame
&& ( abs(v) * 16 < NNUEThreshold2 * r50
|| ( pos.opposite_bishops()
&& abs(v) * 16 < (NNUEThreshold1 + pos.non_pawn_material() / 64) * r50
@@ -1024,3 +1103,5 @@ std::string Eval::trace(const Position& pos) {
return ss.str();
}
} // namespace Stockfish