The ATP World Tour Finals features the top eight performers of 2013, divided into two groups of four with the two best performers in each group advancing to the weekend’s semifinals.  While the groups are evenly balanced on paper, they are less balanced in reality this year.  Read about which contenders harbor more legitimate hopes than others for claiming the prestigious prize in London.

Group A:  Rafael Nadal, David Ferrer, Tomas Berdych, Stanislas Wawrinka

The weaker of the two London groups contains no man who ever has won the World Tour Finals.  Highlighting Group A are two Spaniards who squared off in Paris just a few days ago.

Rafael Nadal:  The world No. 1 has achieved virtually everything worth achieving in this sport:  all four majors, an Olympic gold medal, the top ranking, multiple Davis Cup titles.  Like the Sony Open in Miami, however, the World Tour Finals continues to elude Nadal.  The fast, low-bouncing court dulls his key weapons of movement and topspin while showcasing the superior serves of his rivals.  But a late start to 2013 may have left Nadal fresher at this stage than usual, and he has owned all three of his round-robin foes during the prime of his career.  Granted, he fell to compatriot David Ferrer in Paris yesterday.  Even if Nadal cannot reverse that result in London, though, he has won 15 straight meetings from Tomas Berdych and 11 straight from Stanislas Wawrinka, not even dropping a set to the Swiss.  Two round-robin victories would suffice to earn Rafa the year-end No. 1 ranking and surely a semifinal berth as well.

David Ferrer:  After he looked a shadow of himself for most of the second half, Ferrer finally became Ferrer again during the indoor season.  Three straight finals at Stockholm, Valencia, and the Paris Masters 1000 tournament have revitalized the runner-up at the 2007 World Tour Finals.  Ferrer never has emerged from the role of Best Supporting Actor, but the “Best” matters almost as much as the “Supporting.”  He has won five of six non-clay meetings from Berdych, although he lost to the Czech at the 2011 World Tour Finals.  Ferrer claimed his only previous clash with Wawrinka on an indoor hard court, and one would favor his compact strokes over this opponent’s elongated swings on a fast court.  Some intrigue even swirls around his Tuesday rematch with Nadal, whom this Sancho Panza must believe that he can beat again after years of tilting at windmills against the Mallorcan Don Quixote.

Tomas Berdych:  The only man in London who has not won a title this year, Berdych has underachieved in general against fellow members of the elite.  A loss to Nadal looks nearly assured, for the Spaniard has throttled him on every surface since 2007.  Indoor conditions should help Berdych against Ferrer, in theory, and he mounted an impressive comeback on this court when they met two years ago.  But he must master the mental hurdle of a three-set loss to Ferrer in Paris on Friday, a match that he had chances to win in straight sets.  If he cannot, Berdych might exit London without a victory.  He has struggled against Wawrinka during the latter’s rise, dropping five of their last six meetings.  More valuable evidence might come from their indoor meetings, however, of which Berdych has swept all four.  His match against Ferrer could decide who joins Nadal from Group A in the semifinals. 

Stanislas Wawrinka:  On paper, Wawrinka matches up very well to Berdych and reasonably well to Ferrer, with whom he has split four matches away from clay.  He never has won a set from Nadal, so, like Berdych, he need not sink much hope in the prospect of an upset.  The round-robin format essentially equates to double elimination, though, and a strong start to round-robin play against Berdych could set up Wawrinka for a surprise run.  Without that victory on Monday, the odds grow very long for the only man in the field who has not appeared at the World Tour Finals before.  Accustomed to a physical, grinding brand of baseline tennis, Wawrinka lacks the forecourt attack or overwhelming serve that this surface rewards.  Debutantes in this event typically have not produced their best tennis, Djokovic and Del Potro failing to emerge from the round-robin phase.

Group B:  Novak Djokovic, Juan Martin Del Potro, Roger Federer, Richard Gasquet

Both of the 2012 finalists at the World Tour Finals, and three of the semifinalists, populate the stronger of the two groups.  Round-robin play among them will feature two rematches of scintillating three-setters in Paris last week.

Novak Djokovic:  Just four days after he faced Roger Federer for the first time in 2013, Djokovic will meet him again.  The defending champion of the World Tour Finals has split his two meetings with the Swiss superstar at this tournament, including a pulsating final last year in which he came from behind in both sets.  A 17-match, three-title winning streak propels Djokovic into the World Tour Finals, punctuated by three straight victories over top-eight opponents.  In 2010, the Serb seemed to look ahead to the Davis Cup final during his week in London.  He cannot afford to do the same against a resurgent Federer, who ended his campaign that year.  That match may not matter much to Djokovic in the end, for his dominance on hard courts against Juan Martin Del Potro and his dominance everywhere against Richard Gasquet should give him the two victories that he needs to advance from group play.

Juan Martin Del Potro:  No man has scorched through the fall in form as torrid as Djokovic, but Del Potro has come closer than anyone to matching him.  The 2009 US Open champion came within a tiebreak of winning his first Masters 1000 title in Shanghai while collecting the main prize in Tokyo and Basel.  Fatigue sometimes catches up to Del Potro after such a relentless stretch, which appeared to happen when he faded late against Federer in Paris.  Their third match this fall could prove the key to determining who advances with Djokovic into the semifinals.  Del Potro won both of their previous meetings at the World Tour Finals, and he has swept five straight meetings from Gasquet.  Even the match against Djokovic might not be a lost cause.  Victories at the Olympics last summer and Indian Wells this spring showed that Del Potro can outslug the Serb on surfaces fast and not-so-fast.

Roger Federer:  The record-setting Swiss superstar appears at the World Tour Finals for the 12th consecutive year, having won the title in six of his previous 11 appearances.  Like the nearby lawns of Wimbledon, the surface suits Federer’s game more than most.  His serve crackles through the fast court, the low bounce favors his relatively low contact point on groundstrokes, and plenty of opportunities beckon to exhibit his superlative skills at the net.  Even when Federer slumps at other tournaments, he has soared into vintage form at this tournament, where he cruised to perfect records in 2010 and 2011.  Like Djokovic and Del Potro, he surely can count on a victory over former “Baby Fed” Gasquet.  The rest of his fortunes look more murky.  Federer has collected only two victories over top-eight foes this year, one since January, and he has struggled to string together several matches of his best tennis.

Richard Gasquet:  Hats off to Gasquet for returning to the World Tour Finals after a five-year hiatus.  His only victory at the 2007 event, held in Shanghai, also marked his only career victory over Djokovic.  Gasquet never has defeated Federer on a surface other than clay, and he has not solved Del Potro since the latter was a teenager.  While Wawrinka may bring the least experience of anyone in this eight-man field, this Frenchman seems the most thoroughly outgunned in a group filled with major champions and former World Tour Finals champions.    Like Wawrinka, he may struggle to time his long swings on these fast courts.  Gasquet did win a small title indoors this fall, but he registered no victories over notable opponents during that stretch .His single elite win of the second half came against Ferrer, who inhabits the other group.  This week represents more of a reward than an opportunity for Gasquet.