The hands should move slightly towards the left at follow through and must push down for more back-spin.
The difference of pressure caused by movement of air over the rough and smooth surfaces tends to push the ball to the left.
To a left-handed batter, the swing is in towards the body and towards the leg side which from a technical point of view makes the outswinger, now an inswinger.
Outswingers may be considered to be one of the more difficult fast deliveries for a right-handed batter to play.
This means that any miscalculation can result in an outside edge off the bat and a catch going to the wicket-keeper or slips fielders.