Aspiring Premier League stars can gain just as much from studying Wasim Akram as Gareth Bale, now that aeronautics researchers at the University of Salford have discovered that cricket-style reverse swerve is an important factor in how modern footballs behave in the air.
The addition of rough surfaces intended to make balls go faster has had the unintended side-effect of creating the same aerodynamics as a cricket ball that’s been used for 40 or more overs the researchers say in a study that has won the Catherine Richards prize for the best paper published in journal Mathematics Today in 2012.
The researchers, led by Dr Edmund Chadwick from the School of Computing, Science & Engineering, found that if a high degree of spin is applied to the football which is similar to the forward velocity of the ball, then an unexpected pressure difference will be created, leading to strange movement in the air.
Older footballs didn’t experience this kind of issue since they had a more uneven surface, with seams and smooth surfaces creating a more complex flow of air. Instead the researchers compare the new footballs to cricket balls which gradually get rough on both sides, producing reverse swing, originally used by Pakistani cricketers such as Wasim Akram and Waqar Younis.
Although the Salford team would require simulations to prove individual cases they do believe that it might exonerate Robert Green from his ‘howler’ against the USA in 2010.
Dr Chadwick said: “There was a lot of talk about altitude and the ball being too round at the time of the 2010 World Cup, but we’ve seen with that ball and its successors the addition of rough surfaces to increase speed also makes the ball more unpredictable.
“Applying too much spin will cause movement that the player did not intend and, while this can be beneficial in fooling goalkeepers, it certainly reduces accuracy when striking the ball hard. Better players will need to adjust their games to these new balls and, like much else in sport that will ultimately come down to practice.”