namespace {
// Threshold for lazy and space evaluation
- constexpr Value LazyThreshold1 = Value(1400);
- constexpr Value LazyThreshold2 = Value(1300);
+ constexpr Value LazyThreshold1 = Value(1400);
+ constexpr Value LazyThreshold2 = Value(1300);
constexpr Value SpaceThreshold = Value(12222);
+ constexpr Value NNUEThreshold = Value(500);
// KingAttackWeights[PieceType] contains king attack weights by piece type
constexpr int KingAttackWeights[PIECE_TYPE_NB] = { 0, 0, 81, 52, 44, 10 };
Value Eval::evaluate(const Position& pos) {
if (Eval::useNNUE)
- return NNUE::evaluate(pos);
- else
- return Evaluation<NO_TRACE>(pos).value();
+ {
+ 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();
}
/// trace() is like evaluate(), but instead of returning a value, it returns