And then there is King + Bishop vs. King + Knight, which is not only theoretically drawn but also in a practical sense. The only way to get checkmated is for the player with the knight to position both their pieces in the corner of the same colour as the bishop, which never happens. But it is theoretically possible, and hence lichess does not end the game. Funny thing is, should the knight ever get captured, then lichess concludes the game in a draw due to insufficient material for a mate. Hence as long as the knight is on board, the side with the bishop can try to flag the opponent but has to avoid capturing the knight. I have absolutely no interest in such a game conclusion. 
5 Likes