You'd only need 4 pieces to seal off the corners - one in each corner. They also can't be captured once in a corner, so the only way white would have a chance would be to limit black to those four pieces and force one of them to move.
(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)