The reverse swing or “in-dippers” is possibly one of the most intriguing tricks when it comes to cricket, especially in fast bowling. Swing bowling is when the ball takes a curved path towards the batsman, for the batsman to misjudge the ball.
It is to be one of the deadliest deliveries batsmen have to face. And scientists at IIT Kanpur have decoded the physics behind its execution!
Professor Sanjay Mittal and his two students Ravi Shakya and Rahul Despande of the Institute’s Aerospace department were conducting a series of research on different types of swings in bowling to have a better understanding of the trick and how it is executed.
To gather information, the researchers had observed various factors such as run-up, bowling action, technique, delivery, weather condition, pitch condition, all to connect the factors to a mathematical formula.
During their research, they found that there was a direct connection between the angle of the seam of the ball and the speed to deliver a deadly reverse swing.
Prof Mittal claimed that it was easier for any pacer, medium or fast to deliver a reverse swing by applying a simple physics formula and changing his action at the final delivery of the ball.
He claims that if the pacer delivers the ball by turning the seam 20 degrees downward with a speed of 119-125 kms/hr, a perfect natural swing can be executed.
This specification was observed to get the maximum swing on the ball, depending upon the roughness of the ball and the pitch.
The researcher also studied the connection between the swing and the surface roughness of the ball and found that a rough surface of the ball /pitch helps medium pacers with a speed of 20 and 70 kms.
On the other hand, fast pacers delivering the ball at speeds of 79 to 140 kms/hour and above get a reverse swing if they know the physics behind producing swings.
Interesting to note is that this is how ball tampering cases occur. It’s when a pacer uses a rough object to make the ball surface rough to bring down the thickness of the ball by one millimetre. This condition of the ball helps pacers generate more swings than the usual ball.
It was also noted that swings usually occur well in cold conditions where the air is slightly viscous than hot, dry air.
After inventing the physics formula for swing, the Aerospace department’s research team plans to do its trial on the pitch with real pacers before offering it to the BCCI and Indian coaches for training a new generation of pacers for the Indian Cricket team.
(Edited by Shruti Singhal)