Cricket is a game where batters try to score runs by hitting the ball within or beyond the boundary ropes in a field. The ball is delivered by bowlers who have the ability to bowl fast-paced deliveries (130-150 km/hr) or spin the bowl.
Cricket is a game of shear skill that requires prudent eye-hand co-ordination from the batters. For the bowlers it is important to understand the aerodynamics of the ball by predicting it’s trajectory after the bounce based on the manner in which they grip the seam of the ball. It also depends on the manner in which the pitch behaves.
During a cricket match, the ball is subject to hard-hitting strokes and constant shearing of its skin by grazing through the pitch and grass. After an initial phase of overs, the bowl starts to roughen up. In these initial overs, players ensure that one half of the ball remains shining by polishing it constantly. This makes the ball swing after the bounce, making it difficult for the batter to judge its path.
The ball usually swings in the direction opposite to that on the shining side. If the ball’s shining part is towards the batter (right-handed), then the ball will drift away from him. This is called an outswing. When the ball’s shining part is away from the batter, then the ball swings in the direction of the batter. This is called an inswing.
A reverse swing is a rare tactical skill that only a few bowlers have mastered. A reverse or contrast swing sees the ball swing in the direction of the shining side. The science behind the reverse swing is that the rough side is protected from the development of a boundary layer on its surface. When the ball is released, the shining side, which is more exposed to the air thus receives greater air coverage, making the ball swing in the direction of the shining side. The reverse swing delivery also sees the bowler release the ball slightly later than his or her usual release point. However, this difference is very subtle for the batter to predict an incoming reverse swing.
In order to generate the reverse swing, the ball needs to be worn-out sufficiently on one side. Players have been fined or suspended for breaching the code of conduct for tampering the ball to make the ball reverse. Hence, players need to be patient for the tail-end of an innings (35-50 overs) or in the overs after the new ball gets old (12-20 overs) in order to see the ball suitable for reverse swing.
