Slight advantage

Tennis shows how technology can change a sport, but talent will ultimately carry the day, argues David James


It is not only the competitive elite that benefit from advances in equipment design. Many sports have been made safer and more accessible through science and innovation.

In tennis, subtle technological advances have changed the nature of the game. Since the development of the oversize racket in 1976, tennis is now a far faster sport, with fewer rallies and more stopping time.

While many argue this has diminished the enjoyment for spectators, it has become easier and more accessible to play. Modern materials have allowed tennis rackets to become lighter and stronger. The classic wooden racket with its small string bed and solid shaft is actually a stronger design than modern oversize rackets. The racket head was small so it effectively resisted the huge forces exerted on it.

The oversize design is far more prone to twisting and breaking during play. To overcome this engineering disadvantage, oversize rackets have had to rely on the latest super-stiff materials such as graphite, carbon and Kevlar to provide overall strength. Today we see rackets with massively oversize string beds, very stiff and strong constructions and all at a weight so light that some top players choose to artificially add mass to their frames.

So how has the oversize racket made tennis faster? For most novices, the larger string bed has allowed them to hit shots that they would have normally missed. They can get away with being less accurate, but for the top professionals this is not really an advantage because they are all very accurate all the time. In actuality, the principal reason why the oversize racket has made tennis faster is due to players being able to hit the ball with more top spin.

As Isaac Newton noticed, hitting the ball with top spin makes it dip in flight, thereby helping it land within the court. In comparison, the same ball hit with no top spin may overshoot the court and the point will be lost. When the ball spins it changes the airflow around it and creates a transverse force. In this instance the force acts with gravity to push the ball down to earth.

An oversize racket makes hitting the ball with top spin much easier because players can angle the racket more without fear of the ball clipping the edges of the frame. With more top spin applied, the downward force is greater and players can hit the ball harder knowing that it will land inside the court.

Rackets have also been made with increasing stiffness, meaning less energy is lost during impact. Much attention has been paid to minimising vibrations at the hand with damping devices and the manipulation of ‘sweet spots.’ With advances in racket technology it is not surprising the speed of the game has increased. But the days of the dominance of the ‘big hitters’ may be numbered.

Much research has been conducted to investigate the effect of increasing the size of the ball to slow the game down. By increasing its size by just seven per cent, it will slow more during flight and provide opponents with a fraction of a second longer to react to those powerful shots from the likes of Roger Federer and Rafael Nadal.

The oversize ball effectively combats the advances made through the introduction of the oversize racket. However, whether the larger ball will be accepted at professional level remains to be seen, and it is certain that the powerful players will strongly resist any change that will slow their 150mph serves.

Technology moves forward and new ideas will always be incorporated into sporting equipment. Undoubtedly the best interests of any sport are served if those who control the rules of the game are fully aware of how new technologies may be changing the playing field.

With careful observation, new rules can be introduced to disallow certain technological innovations that may give some athletes an unfair advantage.

Most new technologies that crop up in sporting equipment will only offer the user the slightest advantage. In the main, the best athletes and best teams will always triumph. Technology can help, but it can’t win for you.

David James is a lecturer in sports engineering at Sheffield Hallam University