using namespace std;
-using namespace Stockfish::Eval::NNUE;
namespace Stockfish {
attackedBy[Us][Pt] = 0;
- while (b1) {
+ while (b1)
+ {
Square s = pop_lsb(b1);
// Find attacked squares, including x-ray attacks for bishops and rooks
return v;
}
- // specifically correct for cornered bishops to fix FRC with NNUE.
+
+ /// Fisher Random Chess: correction for cornered bishops, to fix chess960 play with NNUE
+
Value fix_FRC(const Position& pos) {
- Value bAdjust = Value(0);
+ constexpr Bitboard Corners = 1ULL << SQ_A1 | 1ULL << SQ_H1 | 1ULL << SQ_A8 | 1ULL << SQ_H8;
- constexpr Value p1=Value(209), p2=Value(136), p3=Value(148);
+ if (!(pos.pieces(BISHOP) & Corners))
+ return VALUE_ZERO;
- Color Us = pos.side_to_move();
- if ( (pos.pieces(Us, BISHOP) & relative_square(Us, SQ_A1))
- && (pos.pieces(Us, PAWN) & relative_square(Us, SQ_B2)))
- {
- bAdjust -= !pos.empty(relative_square(Us,SQ_B3)) ? p1
- : pos.piece_on(relative_square(Us,SQ_C3)) == make_piece(Us, PAWN) ? p2
- : p3;
- }
- if ( (pos.pieces(Us, BISHOP) & relative_square(Us, SQ_H1))
- && (pos.pieces(Us, PAWN) & relative_square(Us, SQ_G2)))
- {
- bAdjust -= !pos.empty(relative_square(Us,SQ_G3)) ? p1
- : pos.piece_on(relative_square(Us,SQ_F3)) == make_piece(Us, PAWN) ? p2
- : p3;
- }
- if ( (pos.pieces(~Us, BISHOP) & relative_square(Us, SQ_A8))
- && (pos.pieces(~Us, PAWN) & relative_square(Us, SQ_B7)))
- {
- bAdjust += !pos.empty(relative_square(Us,SQ_B6)) ? p1
- : pos.piece_on(relative_square(Us,SQ_C6)) == make_piece(~Us, PAWN) ? p2
- : p3;
- }
- if ( (pos.pieces(~Us, BISHOP) & relative_square(Us, SQ_H8))
- && (pos.pieces(~Us, PAWN) & relative_square(Us, SQ_G7)))
- {
- bAdjust += !pos.empty(relative_square(Us,SQ_G6)) ? p1
- : pos.piece_on(relative_square(Us,SQ_F6)) == make_piece(~Us, PAWN) ? p2
- : p3;
- }
- return bAdjust;
+ constexpr int penalty1 = -209;
+ constexpr int penalty2 = -136;
+ constexpr int penalty3 = -148;
+
+ int correction = 0;
+
+ if ( pos.piece_on(SQ_A1) == W_BISHOP
+ && pos.piece_on(SQ_B2) == W_PAWN)
+ correction += !pos.empty(SQ_B3) ? penalty1
+ : pos.piece_on(SQ_C3) == W_PAWN ? penalty2
+ : penalty3;
+
+ if ( pos.piece_on(SQ_H1) == W_BISHOP
+ && pos.piece_on(SQ_G2) == W_PAWN)
+ correction += !pos.empty(SQ_G3) ? penalty1
+ : pos.piece_on(SQ_F3) == W_PAWN ? penalty2
+ : penalty3;
+
+ if ( pos.piece_on(SQ_A8) == B_BISHOP
+ && pos.piece_on(SQ_B7) == B_PAWN)
+ correction += !pos.empty(SQ_B6) ? -penalty1
+ : pos.piece_on(SQ_C6) == B_PAWN ? -penalty2
+ : -penalty3;
+
+ if ( pos.piece_on(SQ_H8) == B_BISHOP
+ && pos.piece_on(SQ_G7) == B_PAWN)
+ correction += !pos.empty(SQ_G6) ? -penalty1
+ : pos.piece_on(SQ_F6) == B_PAWN ? -penalty2
+ : -penalty3;
+
+ return pos.side_to_move() == WHITE ? Value(correction)
+ : -Value(correction);
}
-} // namespace
+} // namespace Eval
/// evaluate() is the evaluator for the outer world. It returns a static
else
{
// Scale and shift NNUE for compatibility with search and classical evaluation
- auto adjusted_NNUE = [&](){
- int mat = pos.non_pawn_material() + 2 * PawnValueMg * pos.count<PAWN>();
- Value nnueValue = NNUE::evaluate(pos) * (641 + mat / 32 - 4 * pos.rule50_count()) / 1024 + Tempo;
+ auto adjusted_NNUE = [&]()
+ {
+ int material = pos.non_pawn_material() + 2 * PawnValueMg * pos.count<PAWN>();
+ int scale = 641
+ + material / 32
+ - 4 * pos.rule50_count();
+
+ Value nnue = NNUE::evaluate(pos) * scale / 1024 + Tempo;
if (pos.is_chess960())
- nnueValue += fix_FRC(pos);
+ nnue += fix_FRC(pos);
- return nnueValue;
+ return nnue;
};
// If there is PSQ imbalance use classical eval, with small probability if it is small