Wil: DG is much smarter and does take care of all such cases, to the point of pre-playing moves to speed things up. But DG is only for BG, so it can afford the extra system load, whereas BK... ;)
(hide) If you want to play a game with an opponent of a similar level, you can define a required BKR range for a new game invitation. Then nobody with a BKR outside this range will be able to see/accept it. (Katechka) (show all tips)