How cricket ball swings

The essence of swing bowling is to get the cricket ball to move away to the sideways  as it moves it from side to side. The air towards or away from the batsman.

McGrath, Dennis Lillee, Wasim Akram, Irfan Pathan etc are all cricketers of repute. But they have one thing in common. The common factor is that they are all swing bowler. But the thing that connects all of them is they are all Swing bowler.

They all can change the direction of the ball in the air before they touch the ground. In the cricket world it is called the swing of the ball.

How does a cricket ball swing?

Swing a ball depends upon four things:

• The raised seam the ball.
• The wear and tear on the ball
• The delivery speed of the ball
• The action of the bowler

Let’s see how the ball swing…

When the ball is thrown to the air, a thin layer is formed around the ball, it is called the boundary layer. This layer doesn’t remain surrounded the ball all throughout its journey. At certain point of time it is separated from the ball and at the point of time the movement of the ball is determined.

The variety of boundary layer

This layer is of two types: Laminar and Turbulent.

In the laminar layer the air is smooth and regular.

In the turbulent layer, there are rapid fluctuations of air in velocity and pressure.

The boundary layer is sent to the turbulent layer for the seam and so the separation of the ball from the layer is delayed.

Types of swing

There are three types of swing:

• Conventional swing
• Reverse swing
• Contrast swing

 

In the past few years cricketers have been bombered with new and complicated descriptions of the deviation of the ball through the air, but only the select few can distinguish each of them, let alone the science behind them.

 

In the conventional swing, the fast bowlers in cricket make the ball swing by using the primary seam judiciously.  The ball is released with the seam at an angle to the initial line of flight.

 

In the reverse swing the seam actually has a detrimental effect on the turbulent boundary layer by making it thicker and weaker and it therefore separates earlier than the turbulent layer over the bottom surface. Reverse swing generally comes into play with older balls.

 

In the Contrast swing  the direction of the ball is determined by the bowling speed, as opposed to seam and smooth or rough surface orientations. A ball with a contrasting surface roughness is flying through the air at a relatively low speed with the seam straight up.

 

So to re-frame your question why ICC do not choose Tennis ball or any other balls over the current professional cricket ball.