There are 4 pieces on the board, the white and black kings, as well as 2 white bishops (on differently colored squares).
The only way a stalemate occurs is if the black king is not in check, but cannot make a move. (No threefold repetition, timer, etc.) Remaining rules are same as chess.
Assuming perfect play by both players, give the position of the board where white wins, but requires the maximum possible moves to do a checkmate.