I do not think our full backs are good enough defensively for a 433 to work as I can see the wide players of the forward three having to spend most of their time tracking back to support them meaning that the formation quickly becomes a 451. Also do not think that a midfield 3 of Kerr, McDonald and Duff is strong enough to play against at least one if not two more in midfield every week. Can see them getting over run. Would much rather we stuck with 442.