Sumerian: Because there are really only 480 different positions. Each of the 960 positions can be paired with its mirror image. So the 960 positions is really 480 pairs.
(sakla) 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) (Bütün ipuçlarını göster)