I will try to find the swedish original and see what it says about the rules. I didn´t know this was the only detailed source to this truly fascinating game. Since most information seems to be second handed, I will see if this brings any clarification.
(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)