London, May 10 : In 2005, England stole the Ashes series from Australia by reverse swinging the ball earlier than it had been done before, according to a Melbourne engineer who is quite passionate about the game.

When the Pakistan bowlers first introduced it in modern cricket, reverse swing was considered a dark art, a trick gained by doing a deal with the devil.

England's opening bowlers, Matthew Hoggard and Steve Harmison, were dangerous enough, but when captain Michael Vaughan threw the ball to change bowlers, Simon Jones and Andrew Flintoff, things got worse, as the ball began to reverse when it seemed relatively shiny on both sides.

Roger La Brooy, an associate professor in the School of Aerospace, Mechanical and Manufacturing Engineering at Melbourne's RMIT University, has since cracked the code.

He says that it was essentially a matter of scientific compulsion and national pride.

"The phenomenon of reverse swing was well known for a long time, but the mechanism by which it occurred was not clear and more importantly the method by which that ball was reversing after 10 overs was a total mystery. That was something that had never been seen or done before. It had me fascinated and I started writing up notes, and could not fathom how the English were doing it," he was quoted by The Australian, as saying.

He says he began to stay up later and watch the SBS coverage more closely for clues. He noticed the opening bowlers rehearsing a very disciplined delivery drill even as they stood on the boundary between overs. They were practising to barrel the ball - rotate it on an identical axis every time - and it seemed to La Brooy as if they were working at a means of landing the ball very deliberately and carefully on the wicket.

When, during the fifth Test, the cameras managed to provide a lengthy close-up of the ball on the pitch after a dismissal early in the Australian innings, La Brooy noticed that there was a pattern of systematic scarring occurring on one side of the ball, very close to the seam.

It was well known that allowing one side of the ball to get scuffed while shining the other eventually led to swing, but the engineer noticed that this ball was only marked close to the seam while both extremities were shiny.

This was something new and something that took a visual cue away from the batsman, who would normally be looking for the shiny side of the ball as an indicator of which way the ball might swing.

La Brooy had the advantage of working with aerodynamics experts at the university and he had access to a large wind tunnel that was used for mechanical and automotive engineering.

La Brooy and his team began to test the theory.

They sat a cricket ball in a cradle and spun it backwards to mimic the way a bowler gets a ball to rotate on its axis.

La Brooy believed the opening bowlers were drilled to land it time after time just to one side of the seam.

La Brooy emphasised that the scarring was done legitimately, despite all the accusations of bottle tops, peppermints and well manicured fingernails that normally pop up when reverse swing is reported.

He does state that a small lifting of the quarter seam in the area adjacent to the main seam can have the same effect as repeatedly landing the ball in the position.

"We simulated the scarring on our wind tunnel ball and we confirmed visually where the thin layer of air clinging to the surface of the ball, called the boundary layer, separated from the ball very early," he said.

"This would cause a force imbalance to occur on the ball, swinging it in the opposite direction to what would be normally expected. It doesn't take very much sideways force to make the ball move even a quarter of the width of a bat from left to right or from right to left in order to deceive the batsman."

La Brooy's work was presented to Cricket Australia and has been used in various coaching clinics.

ANI