Cricket swing theory does not hold water: study

May 30, 2012
Photo illustration. The widely-held belief that moisture in the air during humid conditions helps make a cricket ball swing has been clean bowled in a scientific study.

The widely-held belief that moisture in the air during humid conditions helps make a cricket ball swing has been clean bowled in a scientific study.

Swing bowling -- when a delivery curves sideways in mid-air -- has long been regarded as one of the game's dark arts, not only deceiving hapless batsmen but also puzzling cricket-loving scientists.

Researchers from Britain's Sheffield Hallam University and the University of Auckland in New Zealand reviewed scientific literature on the subject and conducted their own tests to try to get to the bottom of the mystery.

From the earliest studies of the phenomenon in the 1950s to the "seminal review of sports ball dynamics" by NASA scientist Rabindra Mehta in 1985, they found was consistently cited as a crucial factor in achieving swing.

The researchers tested the theory using 3D laser scanners in an atmospheric chamber to measure the effect different humidity levels had on deliveries using balls which had been "aged" to simulate match conditions.

While altitude and the age of the ball both increased swing, the scientists did not discover any link between moisture levels in the air and sideways movement of the ball.

Photo illustration. While altitude and the age of the ball both increased swing during bowling, the scientists did not discover any link between moisture levels in the air and sideways movement of the cricket ball.

"This study shows that there is no direct or indirect manner in which humidity can significantly affect the ability of the bowler to make the ball swing," they concluded in research published in the online journal Procedia Engineering this week.

"It is therefore logical to conclude that humidity may not have the significant influence on swing bowling that is widely assumed."

Instead, the researchers put forward their own theory that cloud cover provided the ideal environment for swing bowling because it reduced in the air caused by heating from sunlight.

They said such still conditions meant the air surrounding the during the delivery was less likely to be disturbed, making it easier to produce the "asymmetrical" flight needed for swing bowling.

"What is clear is that the scientific community should turn their attention away from the question of humidity and focus their efforts to test the cloud cover hypothesis," they said.

Explore further: The unifying framework of symmetry reveals properties of a broad range of physical systems

add to favorites email to friend print save as pdf

Related Stories

The Physics of a golf swing

Nov 06, 2007

Ever wondered about the science behind your golf swing? Or what the perfect swing 'sounds' like? Last week an expert in the physics of golf has visited the home of golf to talk about technology aimed at developing 'the perfect ...

Rosetta right on track for Earth swing-by

Nov 13, 2007

Preparations for Rosetta’s Earth swing-by scheduled for tonight, 21:57 CET, are well underway. The manoeuvre executed on 18 October 2007 has been accurate enough to not require any additional trajectory ...

Ray Charles really did have that swing

Dec 04, 2006

Ray Charles was really good at snapping, said musical acoustician Kenneth Lindsay of Southern Oregon University in Ashland. Charles's snaps that open "It Don't Mean a Thing (If It Ain't Got That Swing)" are timed so well ...

Cricket ball quality hit for six

Nov 26, 2008

(PhysOrg.com) -- A study by a University of Adelaide sports engineer shows that not all cricket balls are consistently manufactured, causing quality issues and potentially having major implications for cricket ...

Recommended for you

What time is it in the universe?

Aug 29, 2014

Flavor Flav knows what time it is. At least he does for Flavor Flav. Even with all his moving and accelerating, with the planet, the solar system, getting on planes, taking elevators, and perhaps even some ...

Watching the structure of glass under pressure

Aug 28, 2014

Glass has many applications that call for different properties, such as resistance to thermal shock or to chemically harsh environments. Glassmakers commonly use additives such as boron oxide to tweak these ...

Inter-dependent networks stress test

Aug 28, 2014

Energy production systems are good examples of complex systems. Their infrastructure equipment requires ancillary sub-systems structured like a network—including water for cooling, transport to supply fuel, and ICT systems ...

Explainer: How does our sun shine?

Aug 28, 2014

What makes our sun shine has been a mystery for most of human history. Given our sun is a star and stars are suns, explaining the source of the sun's energy would help us understand why stars shine. ...

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

desai_nirav_12
not rated yet May 30, 2012
The cricket ball swings after extensive use in a match when one side of the ball loses its shine and other does not. This creates a difference in air speeds on two sides of the ball causing it to swing. It does not involve tampering with the seam of the ball as that is illegal. The ball is held by the 2 index fingers over the seam and as the ball glides through the air the difference in air pressures ( due to differential roughness and air friction ) causes the ball to swing.
gwrede
not rated yet May 30, 2012
Some tennis courts and TV-stations have equipment that track the 3D trajectory of a tennis ball. To exactly know the rotation of the ball, we need felt tip markings on the ball and a high-speed camera next to the thrower.

All we then need, is an expert thrower and a few tries in different kinds of weather. Or, to get really scientific, we could construct a mechanical arm (a la Mythbusters) with precise and repeatable throws, with and without screw.

Personally I think, if humidity made any difference, then soccer players would always have known about it.