The smallest change in the velocity or direction of a cricket ball can have a dramatic effect on the outcome of a match.
This means that the smallest change in the composition of the ball – particularly the roughness of its exterior – can make a big difference to how a match is played. Changing the colour – for instance, to pink, for the recent innovation of day-night tests – can have even bigger implications.
So what precisely goes into making a cricket ball – and is there any chemical difference between the pink and red balls?
The composition of cricket balls have not changed much over the past century. The centre of the balls are made from cork. This is surrounded with yarn, and then encased in pre-dyed leather hemispheres. These materials – all malleable but dense – give the balls their characteristic weight and bounce.
The leather is stitched in with linen thread, and the balls are stamped and lacquered to give the leather its finish. Importantly, this should make the leather tough but not indestructible: like the pitch, a good cricket ball should change its behaviour as it wears down over a match.
The leather is pre-dyed before being shaped into a ball – either red, pink, or white, depending on the format of the game.
“The quality of the leather used between the red, pink and white Kookaburra Turf balls remains consistent,” says David Orchard, general manager of Kookaburra, which supplies all of Australia’s test cricket balls, as well as those of several other countries.
“With the pink ball, the lacquer is actually the same as for the red ball, the only differences are the pink finish that goes on the leather to ensure its visibility under lights, and the black seam that creates the contrast.”
So, in a chemical sense, the only difference between pink and red balls is the dye on the leather and the seam. Given the balls are then coated with the same sort of lacquer (in Kookaburra’s case, a nitrocellulose-based lacquer), the dye should not make much difference to the behaviour of the ball.
“There is some belief that the pink finish helps swing early, but this is really hard to quantify or be definitive about,” says Orchard.
“Like with any cricket ball it is pitch and weather conditions, and of course the skills of the bowler, that have far more influence on the ability of the ball to move than the ball itself.”
Given the pink ball is a markedly different colour to red and white balls – that’s the point – it’s likely that its visibility has an effect on how it’s bowled and hit, as well. It’s also been proposed that it’s the moister evening conditions that are having an effect on swing.
Regardless of its colour, any type of ball being used at a higher level spends a long time in development, so that the manufacturers can ensure it’s not going to change the nature of the game.
Orchard says that the amount of time spent developing a new ball differs depending on the ball.
“The Kookaburra Turf Pink Ball for example took almost eight years to perfect from make-up to final testing for test match use.”
Development first requires “input from players and governing bodies to ensure the product is perfect for the players and the playing conditions”.
Once a prototype has been made, it then spends a long time getting tested.
“For the pink Kookaburra Turf Ball, this involved testing in collaboration with players and the governing bodies from ECB testing in Abu Dhabi to Shield testing here in Australia,” says Orchard.
“The ball testing incorporates different conditions and playing surfaces, to ensure we maintain the balance between bat and ball which is at the core of what we do.”
Ellen Phiddian is a science journalist at Cosmos. She has a BSc (Honours) in chemistry and science communication, and an MSc in science communication, both from the Australian National University.
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