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 only look at some of the discussion boards on a regular basis you can add them to your favourite boards list by going to the Board page and clicking "Add to my favourite boards". (pauloaguia) (Bütün ipuçlarını göster)