The tennis world is currently experiencing a major shift in power as Roger Federer looks set to be usurped as world number one by Rafael Nadal. Nadal has been Federer’s closest rival this year and from August 18, 2008 he will be officially the new men’s number one.

The two tennis heavyweights recently competed against each other in the 2008 Wimbledon final where Nadal was able to overcome the previously unstoppable Federer, in arguably the greatest men’s final ever played.

Since the turn of 2008 the form of the two rivals could not have been any different. Nadal has gone from strength to strength and dominated the courts with his power, stamina and hugely impressive array of shots, winning The French Open and Wimbledon, and reaching the semi final of the Australian Open already this year. Federer on the other hand, has suffered the worst form of his four-and-a-half year stint as world number one and following Wimbledon has made an early exit from the Rogers Cup and Cincinnati Masters. His dip in form could not come at a worse time as the Olympics get closer.

Previous major tennis tournaments have often been dominated by Nadal and Federer, with the final often being played between the two. However with Federer’s lack of form and confidence he will now go into the Olympics facing an uphill struggle to make the podium let alone challenge for gold. Nadal will of course enter the Olympics as favourite but will be wary of the threat posed by the two recent finalists of the Cincinnati Masters. Nadal was defeated in the semi-final of the 2008 Australian Open by the third seed Djokovic who went on to win the final.

The other medal contender comes in the shape of Great Britain’s Andy Murray who defeated Djokovic in Cincinnati to win his first career tournament. Murray also had a strong tournament at Wimbledon but his record against Nadal will be of concern, having lost all five matches he’s played against him.

The women’s Olympic tennis will also see a strong turn out from the top seeds but Maria Sharapova will not be competing. The world number four was forced to withdraw from the Olympics following a recent shoulder injury.

Sharapova is not the only absentee following the shock retirement of Justine Henin in May. Henin cited the pollution issues as the reason why she would not compete in Beijing and this has left the tournament wide open.

Venus and Serena will be favourites to repeat their all-Williams final at Wimbledon this year, but will face a very strong Serbian threat from world number one Ana Ivanovic and world number two Jelena Jankovic. Both Serbians had a torrid time at Wimbledon but neither can be written off and this will make the women’s tournament an absorbing affair.

China’s best hope of achieving success in the singles will come in the form of Wimbledon semi-finalist Jie Zheng, and although she will have overwhelming crowd support it is unlikely she will be able to match the quality of the other competitors. Many will see the powerful and athletic Venus Williams as tournament favourite following her impressive victory at Wimbledon but this is by no means a foregone conclusion, leaving the final podium standings very much unknown.