When it comes to the World Cup Jabulani football, perfect may not be good enough, according to scientists who have analysed the controversial ball.
Experts puzzling over its allegedly erratic flight — which has unnerved more than one goalkeeper in South Africa — have concluded that the Jabulani may simply be too round to fly straight.
Since being chosen for the World Cup, the adidas-made ball has come in for a serious drubbing. Spain’s Iker Casillas has dissed it as “rotten,” while Italy’s goalkeeper Gianluigi Buffon tagged it “unpredictable.”
Part of the problem may be that “the stitches of the Jabulani are internal, so the ball resembles a perfect sphere,” said Eric Berton, deputy director of the Institute of the Science of Movement in Marseille, France. In other sports — tennis, golf or baseball — the balls have irregularities precisely to insure a more stable and controlled trajectory. The ridges or exposed seams are what make possible spin in tennis or a curveball pitch in baseball.
Despite the Jabulani’s so-called ‘grip’n’grove’ texturing, however, the ball apparently doesn’t behave in the same way. “Because of the shape, the time of contact with the foot is reduced,” said Berton.
“As a consequence, it practically doesn’t spin. The ball travels a little less far, and will have a floating and unpredictable trajectory, whether for a striker or a goalkeeper,” he said.
— AFP