Will Roger Federer and Serena Williams Make U.S. Open History?

Serena Williams of the U.S. serves to Vitalia Diatchenko of Russia during their match at the U.S. Open Championships in New York, August 31. Lucas Jackson/Reuters

This article first appeared on The Conversation.

Moneyball was just the start. In the 12 years since Michael Lewis's book lifted the lid on how the Oakland Athletics baseball team used detailed statistical analysis to compete with the best despite low budgets, every competitive sport has become more data driven.

Nowadays, the technology has evolved to the point where the challenge has shifted from capturing data to separating the useful stats from the rest. Tennis is a case in point.

The Association of Tennis Professionals (ATP) publishes vast amounts of data throughout the competitive season. Much of it is noise, but some can explain profound changes in a player's success.

In the buildup to the U.S. Open, the ATP data has presented a fascinating insight into tactical changes that have brought Federer back to No. 2 in the world and led him to recently defeat both Andy Murray and Novak Djokovic in the Cincinnati Masters.

The statistics show that the number of service games that Federer has won has reached a career high this season. This is thanks to the fact that the Swiss is winning more points specifically on his first service.

It looks even more pronounced when viewed in contrast to his dip in performance and world ranking in 2012 to 2013. It appears that in the autumn of his career, at 34 years of age, Federer's game has become much more attacking. This points to the influence of both Stefan Edberg, Federer's coach, and Tony Pickard, Edberg's mentor.

Previously, Federer would serve and wait at the baseline, relying on his powerful ground shot and improvisation to stay in the point and force errors. Now his first service is followed by an aggressive move to take the service return nearer the net and at waist height, forcing his opponent onto the defensive. This has to be supported by physical-conditioning work to sustain the higher physical demands it entails.

Federer has deployed the new approach in Masters events, where games are played over three sets, but he has been more sparing in games over five sets. Having said that, it was exactly this approach that defeated Murray at Wimbledon and almost brought Federer the title for the eighth time.

If Federer is to win the U.S. Open, he will need to do it over five sets once again and recover between his seven matches. It has been four years since the Swiss has won a grand slam title—the Australian Open, French Open, Wimbledon and the U.S. Open—and eight years since he won the latter. But if he can maintain the physicality required by his new approach, he is a real contender.

Serena's Swansong?

The only player who could trump a Federer victory would be Serena Williams, for whom a win in New York would be one of the greatest achievements in the history of tennis. It would give her a calendar grand slam—winning each of the four majors in a calendar year.

Only three other female players have achieved this: Maureen Connolly (1953), Margaret Court (1970) and Steffi Graf (1988). Names as big as Martina Navratilova and Chris Evert have tried and failed at what is a mark of enduring dominance. It would also mean that Williams had won five grand slams in a row (equaling Graf and one behind Court and Navratilova).

Williams is approaching her 34th birthday too, but many believe the comparisons with Federer end there. They dismiss her achievements as indicative of the lack of real competition and depth in the women's game, but this is simply not the case.

True that the position of world No. 1 has not been as tightly contested, but the spread of major titles over the past five years suggests around a dozen women could challenge Williams—if they have a good day and she has a bad one.

The onus is therefore always on her to be at her very best. This is why people glibly say that the only person who can beat Williams is herself.

Is she the effortless player we often see breezing past opponents on court? Or is there any substance to the claim made by Pat Cash and others that she has a more fragile psychology, pointing to her verbally lashing out at other players, court officials and herself? A classic example was the on-court row we witnessed with the umpire at the U.S. Open in 2011.

What cannot be debated are her magnificent results: 21 majors, putting her all-time third among women. Win the U.S. Open, and she will move up to equal second with Graf, leaving her two behind Court's 24.

Has she enough time to scale this final summit? Until she hangs up her racquet for the last time, it would be foolish to rule anything out.

Tony Westbury is lecturer in sport psychology at Edinburgh Napier University.