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 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)