Dr Ken Bray, a physicist at Bath University, has studied
free-kicks from Premiership, World Cup and European Championship
matches and found that top players such as the Manchester United
star Cristiano Ronaldo are exploiting the chaotic flight and speed
of modern balls to score goals.
Speaking at the British Association for the Advancement of
Science Festival in Liverpool, Dr Bray called on football's
governing body, Fifa, to step in with new regulations on
aerodynamic qualities of footballs. He argued that Fifa already
dictates the size, weight and bounce of footballs used in
competitive matches, but does not specify how the ball should
behave when it is kicked.
With professional players able to kick the modern lightweight
balls harder and faster than previous generations, the flight of
the ball is an important issue.
Dr Bray said: "Fifa dictates all aspects about ball design apart
from the aerodynamics, yet there is no reason why you couldn't
design a football so that you know if you spin the ball as much as
Beckham for example, you know how much it will swerve in
flight."
Ronaldo, 23, is feared for his free-kicks that cause the ball to
change direction unpredictably in mid-air, bewildering
goalkeepers.
Unlike players such as David Beckham, who mastered the ability
to put spin on the ball so that it dipped and swerved into the net,
Ronaldo kicks the ball so that it barely spins on any axis. This
means that as air rushes over the seams of the ball it creates
turbulence that can suddenly change the ball's trajectory at
random.
"While Beckham can reasonably predict where his shot will end
up, with Ronaldo it is down to the physics of chaos once the ball
leaves his foot. It makes it very disconcerting and unfair for
goalkeepers," said Dr Bray.
