+ Square winnerKSq = pos.king_square(strongerSide);
+ Square loserKSq = pos.king_square(weakerSide);
+ Square pawnSq = pos.piece_list(weakerSide, PAWN)[0];
+
+ Value result = QueenValueEg
+ - PawnValueEg
+ + DistanceBonus[square_distance(winnerKSq, loserKSq)];
+
+ if ( square_distance(loserKSq, pawnSq) == 1
+ && relative_rank(weakerSide, pawnSq) == RANK_7)
+ {
+ File f = file_of(pawnSq);
+
+ if (f == FILE_A || f == FILE_C || f == FILE_F || f == FILE_H)
+ result = Value(DistanceBonus[square_distance(winnerKSq, loserKSq)]);
+ }
+ return strongerSide == pos.side_to_move() ? result : -result;