- if (Eval::useNNUE)
- {
- Value balance = pos.non_pawn_material(WHITE) - pos.non_pawn_material(BLACK);
- balance += 200 * (pos.count<PAWN>(WHITE) - pos.count<PAWN>(BLACK));
- // Take NNUE eval only on balanced positions
- if (abs(balance) < NNUEThreshold)
- return NNUE::evaluate(pos);
- }
- return Evaluation<NO_TRACE>(pos).value();
+ bool classical = !Eval::useNNUE
+ || abs(eg_value(pos.psq_score())) >= NNUEThreshold * (16 + pos.rule50_count()) / 16;
+ Value v = classical ? Evaluation<NO_TRACE>(pos).value()
+ : NNUE::evaluate(pos) * 5 / 4 + Tempo;
+
+ // Damp down the evaluation linearly when shuffling
+ v = v * (100 - pos.rule50_count()) / 100;
+
+ // Guarantee evalution outside of TB range
+ v = Utility::clamp(v, VALUE_TB_LOSS_IN_MAX_PLY + 1, VALUE_TB_WIN_IN_MAX_PLY - 1);
+
+ return v;