well i can swing nicely whatever the pitch or swing is. take a good right or left medium (i suggest mcmillan in New Zealand) then when playing as him use 'd' to bowl to the right and 'a' to swing to the left. Next after placing the cursor using 'd' move that small bowl(in left down corner) to the extreme right(for full swing) or top right (for fast moderate swing) or bottom right (for slow moderate swing. Try placing the small ball in mid places to vary spin.
's' is straight ball 'w' is not available for medium bowlers and 'd' and 'a' is swing.