There are two types of swing bowling in cricket: conventional and reverse swing. Conventional swing is where the airflow breaks away from the ball earlier on one (rougher) side of the ball than the other, resulting in more lift on the smoother side of the ball, thus pulling the ball towards the smooth side.
With reverse swing, one side of the ball is so rough that the drag caused produces a greater force than the lift on the smooth side, pulling the ball in the direction of the rough side, which is why reverse swing bowlers get the best results from an old ball.
Last edited by CAT1; 3rd October 2005 at 10:18.