- bool classical = largePsq || (psq > PawnValueMg / 4 && !(pos.this_thread()->nodes & 0xB));
-
- // Use classical evaluation for really low piece endgames.
- // The most critical case is a bishop + A/H file pawn vs naked king draw.
- bool strongClassical = pos.non_pawn_material() < 2 * RookValueMg && pos.count<PAWN>() < 2;
-
- v = classical || strongClassical ? 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
- && ( abs(v) * 16 < NNUEThreshold2 * r50
- || ( pos.opposite_bishops()
- && abs(v) * 16 < (NNUEThreshold1 + pos.non_pawn_material() / 64) * r50
- && !(pos.this_thread()->nodes & 0xB))))
- v = adjusted_NNUE();