Swing bowling in cricket: Conventional Swing

Swing bowling in cricket is considered one of the classy art that the fast bowlers possess.

I’m sure people reading this would have seen cricket players shinning the ball trying to maintain the shine on the ball.

Ever wondered why fielders continuously try to shine the ball on one side? Is it only to maintain the shine of the ball or is there any science behind it? Let’s dig right in.

The intention behind shinning the ball is to help their bowlers swing the ball while bowling to the batsman. How is it, do you ask?

Impact of shinning the ball and air flow:

Players shine on one side of the ball so that when the bowler releases the ball the air flow, in the cricket ground, would assist the ball to swing in the air.

When one side of the cricket ball is shiny and the other side is rough and if the bowler presents the seam straight, the seam of the ball cuts through the air and the air is separated at the seam.

On the shiny side of the ball the air flows smoothly, which is a laminar flow. On the rough side the air flows chaotically, which is a turbulent flow.

Swing bowling with a new ball

The air glides along the shiny side and leaves the shiny side earlier than the air on the rough side.

When the air on the shiny side leaves the surface of the ball early the ball experience a force. The force experienced by the ball is in the opposite direction towards the rough side.

As a result the ball swings towards the rough side.

Let’s imagine it this way, when you wear a jet pack with two outlet nozzles, if the right side nozzle is fired first, you obviously will fly to the opposite side i.e. to the left, right? The same can be assumed for swing bowling in cricket.

So, if you are bowling to a right handed batsman and the shiny side of the ball is to your right then it is called an out-swinger. If the ball is towards the left side then it is an In-swinger.

And for a Left hand batsman it’s the opposite.