Great serve, for a guinea-pig ...

As tennis players have got bigger and stronger, the balls have been flying ever faster. Now they are set to slow down, says Charles Arthur

The professional tennis players gracing the courts at Wimbledon may be rich and famous. But they are also unwitting guinea-pigs in a worldwide experiment, in which the laws of physics - and especially aerodynamics - are being harnessed to make the game more entertaining.

The key to the experiment lies in the tennis balls. What tournament organisers really want are balls that look and feel just like the present ones, but fly through the air more slowly.

The past 10 years have seen the emergence of the "power game". Tennis rackets have become up to 20 per cent more powerful as manufacturers use stiff graphite fibres to make larger-headed models. The players themselves have become taller and stronger: most of the top 10 men players are over 6ft, compared to only a handful 20 years ago. But the tennis balls have stayed the same.

The result is that service speeds have risen, so that on Centre Court they typically average 100mph, leading to more points where the service is not returned. In a number of countries, especially the United States, many spectators are not coming back either: when asked why not, they say the game is just too boring.

This has put the International Tennis Federation (ITF) in a quandary. Unlike golf, where the twin powers of the Royal & Ancient Club and the US Golf Association legislate on every technical detail - from the number and shape of the grooves in the clubheads to the pattern of dimples on the golf ball - in tennis the ITF sets only a maximum size for the racket, with no limits on its "power". The replacement of wooden rackets with graphite overwhelmed the game, but it's too late to turn back. So now the only option left is to try to slow the game down (and stop spectators getting whiplash as they follow rallies) by altering the balls.

This year, Wimbledon officials and players have tried using balls which are pressurised at 2 per cent below the norm. But in last week's hot weather the balls heated up unusually quickly, reaching the same speed as normal balls within a couple of rallies. Statistics collected by IBM bear this out - there was no difference in the percentage of serves returned.

Dr Geoff Thwaites, of GT technology in Cambridge, last week ran a series of computer simulations of the effect of pressure reduction on tennis balls. He found that while a ball rebounds about 5 per cent less when bouncing from a hard surface, "the velocity of the ball off the racket is only decreased by 1 per cent for the same pressure reduction". And, of course, it is precisely the velocity of the ball off the server's racket which matters if you are trying to give his or her opponent an increased chance of returning a service. Dr Thwaites also warned that softer balls will skid further "and may cause more difficulty with line calls".

The organisers of the French Open, held at Roland Garros in Paris in June, tried a similar experiment, but this time using smaller balls. Their object was to speed up the game rather than slow it down: their floor surface, of crushed brick, is one of the slowest in the world, while Wimbledon's is the fastest.

Two factors are crucial in deciding how fast a ball will fly: the resilience of the rubber (to which the internal pressure contributes); and its effective cross-section, which affects the ball's air resistance. The Wimbledon balls use the same rubber as those in the French Open, but at a lower pressure, meaning that when a racket hits the ball, it "gives" more. This reduces the ball's initial speed. But when the rubber - and consequently the gas inside the ball - heats up, the pressure rises again.

Increasing the cross-section means that the ball slows down more quickly as it flies through the air. "To really have an effect, you would have to look for a 10 per cent reduction in the speed of the balls," says Robert Haines, a technical consultant to the ITF who has worked for ball manufacturer Dunlop-Slazenger for the past 30 years. "You would have to make the ball's cross-section about 20 per cent bigger. To get a 10 per cent reduction through lowering the pressure, you'd get a pretty squashy ball. It would be unsatisfactory to the players." Dr Thwaites reaches a similarly gloomy conclusion from his computer studies: "It seems from these results that little can be done with the ball to change the game."

Some players have been complaining that the softer balls at Wimbledon have led to more wrist strains, because the impact lasts longer. But they can probably console themselves with the thought that they are the best- paid scientific guinea-pigs in the world.

News
Kenny Ireland, pictured in 2010.
peopleActor, from House of Cards and Benidorm, was 68
News
A scene from the video shows students mock rioting
newsEnd-of-year leaver's YouTube film features staging of a playground gun massacre
Travel
travel
Environment
View from the Llanberis Track to the mountain lake Llyn
Du’r Arddu
environmentA large chunk of Mount Snowdon, in north Wales, is up for sale
PROMOTED VIDEO
Voices
A family sit and enjoy a quiet train journey
voicesForcing us to overhear dull phone conversations is an offensive act, says Simon Kelner
News
i100This Instagram photo does not prove Russian army is in Ukraine
Arts and Entertainment
The cast of The Big Bang Theory in a still from the show
tvBig Bang Theory filming delayed by contract dispute over actors' pay
News
Morrissey pictured in 2013
people
Arts and Entertainment
Sydney and Melbourne are locked in a row over giant milk crates
art
Life and Style
The director of Wall-E Andrew Stanton with Angus MacLane's Lego model
gadgetsDesign made in Pixar animator’s spare time could get retail release
News
peopleGuitarist, who played with Aerosmith, Lou Reed and Alice Cooper among others, was 71
News
ebookA unique anthology of reporting and analysis of a crucial period of history
Environment
Tyred out: should fair weather cyclists have a separate slow lane?
environmentFormer Labour minister demands 'pootling lanes' for women cyclists
News
people
Sport
England celebrate a wicket for Moeen Ali
sportMoeen Ali stars with five wickets as Cook's men level India series
News
Field of broken dreams: Andy Bell visits Passchendaele
news5 News's Andy Bell visited the killing fields of the Great War, and his ancestor - known only from his compelling war diary - came to life
Travel
travel
Independent
Travel Shop
the manor
Up to 70% off luxury travel
on city breaks Find out more
santorini
Up to 70% off luxury travel
on chic beach resorts Find out more
sardina foodie
Up to 70% off luxury travel
on country retreats Find out more
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

VB.Net Developer - £40k - Surrey - WANTED ASAP

£35000 - £40000 per annum + competitive: Progressive Recruitment: .Mid Level V...

Digitakl Business Analyst, Slough

£40000 - £45000 per annum + Competitive Benefits: Progressive Recruitment: Dig...

Mechanical Estimator: Nuclear Energy - Sellafield

£40000 - £50000 per annum + Car, Medical, Fuel + More!: Progressive Recruitmen...

Dynamics NAV Techno-Functional Consultant

£50000 - £60000 per annum + benefits: Progressive Recruitment: An absolutely o...

Day In a Page

Dress the Gaza situation up all you like, but the truth hurts

Robert Fisk on Gaza conflict

Dress the situation up all you like, but the truth hurts
Save the tiger: Tiger, tiger burning less brightly as numbers plummet

Tiger, tiger burning less brightly

When William Blake wrote his famous poem there were probably more than 100,000 tigers in the wild. These days they probably number around 3,200
5 News's Andy Bell retraces his grandfather's steps on the First World War battlefields

In my grandfather's First World War footsteps

5 News's political editor Andy Bell only knows his grandfather from the compelling diary he kept during the war. But when he returned to the killing fields where Edwin Vaughan suffered so much, his ancestor came to life
Former Labour minister Meg Hillier has demanded 'pootling lanes' for women cyclists

Do women cyclists need 'pootling lanes'?

Simon Usborne (who's more of a hurtler) explains why winning the space race is key to happy riding
A tale of two presidents: George W Bush downs his paintbrush to pen father’s life story

A tale of two presidents

George W Bush downs his paintbrush to pen father’s life story
Save the tiger: The day America’s love of backyard tigers led to a horrific bloodbath

The day America’s love of backyard tigers led to a horrific bloodbath

With only six per cent of the US population of these amazing big cats held in zoos, the Zanesville incident in 2011 was inevitable
Samuel Beckett's biographer reveals secrets of the writer's time as a French Resistance spy

How Samuel Beckett became a French Resistance spy

As this year's Samuel Beckett festival opens in Enniskillen, James Knowlson, recalls how the Irish writer risked his life for liberty and narrowly escaped capture by the Gestapo
We will remember them: relatives still honour those who fought in the Great War

We will remember them

Relatives still honour those who fought in the Great War
Star Wars Episode VII is being shot on film - and now Kodak is launching a last-ditch bid to keep celluloid alive

Kodak's last-ditch bid to keep celluloid alive

Director J J Abrams and a few digital refuseniks shoot movies on film. Simon Usborne wonders what the fuss is about
Once stilted and melodramatic, Hollywood is giving acting in video games a makeover

Acting in video games gets a makeover

David Crookes meets two of the genre's most popular voices
Could our smartphones soon be diagnosing diseases via Health Kit and Google Fit?

Could smartphones soon be diagnosing diseases?

Health Kit and Google Fit have been described as "the beginning of a health revolution"
Ryanair has turned on the 'charm offensive' but can we learn to love the cut-price carrier again?

Can we learn to love Ryanair again?

Four recent travellers give their verdicts on the carrier's improved customer service
Billionaire founder of Spanx launches range of jeans that offers

Spanx launches range of jeans

The jeans come in two styles, multiple cuts and three washes and will go on sale in the UK in October
10 best over-ear headphones

Aural pleasure: 10 best over-ear headphones

Listen to your favourite tracks with this selection, offering everything from lambskin earmuffs to stainless steel
Commonwealth Games 2014: David Millar ready to serve up gold for his beloved Scotland in the end

Commonwealth Games

David Millar ready to serve up gold for his beloved Scotland in the end