Pallab Ghosh reports: "Fractions of a second make all the difference"

Even an amateur hits the ball harder and faster now than a professional did 20 years ago. Some top players serve at 130mph (210km/h), giving their opponents little chance to hit the ball.

The authorities are trying to slow the game down, and giving the ball more air resistance is one way to do it.

Serves are much faster than 20 years ago

Experiments are under way to test out balls that are up to 8% larger.

Tests over the last two years show the new balls take 0.3secs to cross the court - equivalent to the difference between playing on a fast surface like asphalt and a slower one like clay.

"When it comes in to hit the ground, it comes in slightly steeper and slower which in turn slows the ball down through the air," says Steve Haake of Sheffield University.

Balls could be on sale in six months

If given the go-ahead, there could be three types of new ball, suited to a fast, medium or slow game.

The International Tennis Federation will meet in July to decide whether to ratify the new ball.

"Moving to a bigger ball will provide benefits to the whole game of tennis," said Andrew Coe of the International Tennis Federation.

If it gets the go-ahead, the new larger ball could be in production by January.