Reverse (cricket)

In the sport of cricket, making the ball move in the air with the older ball is called reverse swing.

Conventional swing

The cricket ball often moves in the air towards or away from a batsman when a pace bowler is bowling. It is this deviation most fast bowlers strive for because of the problems it causes batsmen. Swing is all about aerodynamics. Batsmen are used to facing orthodox swing - which happens when the ball is still relatively hard and new in the first 10 to 15 overs.

However, over the past 20 years fast bowlers have developed a new method of making the ball move in the air with the older ball called 'reverse swing'.

But to obtain any sort of movement, there are a number of factors to consider.

The ball

Fielders are often seen continually shining one side of a ball by rubbing it on their trousers. The rubbing helps to maintain a smooth, shiny side while the opposite is left to deteriorate through normal wear and tear. In simple terms, the aerodynamics of bowling means the shiny side travels faster through the air lowering the air pressure on the shiny side causing the ball to deviate in that direction. Other factors also play a part.

Reverse swing

Once the ball becomes older and more worn, it will begin to move in the opposite direction to where it would usually swing with no great change in the bowling grip.

For example, an outswinger's grip will move towards the batsman in the air while an inswinger will move away from the bat. All this tends to happen very late on in the delivery, making it difficult for the batsman to pick up the changes in the air. Not every single bowler can obtain reverse swing - the ball needs to be propelled above 80mph or thereabouts to make it move in the air.

Origin

Former Pakistan international Sarfraz Nawaz was the founder of reverse swing during the late 1970s, and he passed his knowledge on to former team-mate and captain Imran Khan. It was Imran who schooled bowlers Wasim Akram and Waqar Younis, who brought the art to the cricket world's attention during the late 1980s and 1990s. The dynamic duo managed to make the old ball swing a considerable distance at pace in both directions, a skill few bowlers can master.

In a display of reverse swing in a Test match against Australia in 1979 in Melbourne, Sarfraz Nawaz took nine wickets in an innings. This included a remarkable spell of 33 deliveries in which he captured 7 wickets for 1 run. This is when cricket world noticed this new form of fast bowling and started taking it seriously.

Wasim Akram then brought reverse swing to the public limelight but the man who really put the reverse into swing was Waqar Younis. He bucked the 1980s trend of pitching fast and short by pitching fast and full. Not an obvious recipe for success until you factor in prodigious late inswing or reverse swing, which was designed to smash into the base of leg stump or the batsman's toes.

How does it work?

There have been plenty of theories about why, but here's the simplest explanation from former England bowling coach Troy Cooley:

*"Reverse swing is all to do with the deterioration of the ball and the seam position in flight. As the ball becomes rougher, it will take on a different characteristic as it deteriorates. So if you present the ball as an outswinger, the ball has deteriorated so much on the rough side that it takes on the characteristics of the shiny side. Which means a natural outswinger will become an inswinger and conversely, an inswinger into an outswinger."

When does the ball start to reverse?

Since reverse swing favours the older ball, it will usually start to move around the 40-over mark. However, England's bowlers during the 2005 Ashes were able to make the ball reverse after just 15 to 20 overs. Brett Lee found his reverse swing in Adelaide on the 30-over mark.

But how can bowlers manage to do this so early in the innings? One theory could be the ball. In England, Test balls are manufactured by Dukes, while in Australia and the sub-continent the Kookaburra brand is usually used.

Like footballs, each manufacturer's cricket balls are different. Some have more pronounced seams while others deteriorate slower, both of which have an influence on how the ball will move in the air.

Another theory is how some players are able to rough the ball up faster than other teams. In England's case in 2005, Steve Harmison and Andrew Flintoff both banged the ball hard into the pitch. While their fielders often throw the ball back to wicket-keeper Geraint Jones on the bounce from the outfield, all of which contribute to the deterioration of the ball.

However, nothing has been scientifically proven, but batsmen the world over know what to expect when the ball starts to get older.

ee also

*Cricket terminology