return v;
}
-
- /// Fisher Random Chess: correction for cornered bishops, to fix chess960 play with NNUE
-
- Value fix_FRC(const Position& pos) {
-
- constexpr Bitboard Corners = 1ULL << SQ_A1 | 1ULL << SQ_H1 | 1ULL << SQ_A8 | 1ULL << SQ_H8;
-
- if (!(pos.pieces(BISHOP) & Corners))
- return VALUE_ZERO;
-
- int correction = 0;
-
- if ( pos.piece_on(SQ_A1) == W_BISHOP
- && pos.piece_on(SQ_B2) == W_PAWN)
- correction -= CorneredBishop;
-
- if ( pos.piece_on(SQ_H1) == W_BISHOP
- && pos.piece_on(SQ_G2) == W_PAWN)
- correction -= CorneredBishop;
-
- if ( pos.piece_on(SQ_A8) == B_BISHOP
- && pos.piece_on(SQ_B7) == B_PAWN)
- correction += CorneredBishop;
-
- if ( pos.piece_on(SQ_H8) == B_BISHOP
- && pos.piece_on(SQ_G7) == B_PAWN)
- correction += CorneredBishop;
-
- return pos.side_to_move() == WHITE ? Value(3 * correction)
- : -Value(3 * correction);
- }
-
} // namespace Eval
Value psq = pos.psq_eg_stm();
// 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.
- bool useClassical = (pos.this_thread()->depth > 9 || pos.count<ALL_PIECES>() > 7)
+ bool useClassical = (pos.count<ALL_PIECES>() > 7)
&& abs(psq) * 5 > (856 + pos.non_pawn_material() / 64) * (10 + pos.rule50_count());
// Deciding between classical and NNUE eval (~10 Elo): for high PSQ imbalance we use classical,
optimism = optimism * (269 + nnueComplexity) / 256;
v = (nnue * scale + optimism * (scale - 754)) / 1024;
-
- if (pos.is_chess960())
- v += fix_FRC(pos);
}
// Damp down the evaluation linearly when shuffling
std::memset(scores, 0, sizeof(scores));
// Reset any global variable used in eval
- pos.this_thread()->depth = 0;
pos.this_thread()->trend = SCORE_ZERO;
pos.this_thread()->bestValue = VALUE_ZERO;
pos.this_thread()->optimism[WHITE] = VALUE_ZERO;