Over the course of his career, Rafael Nadal has notched tournament victories at a prolific pace, having won 60 titles since 2004.
However, of those, only three have been captured after the year's final Grand Slam, the U.S. Open (Tokyo in 2010, and Madrid and Beijing in 2005), for a shockingly low statistic considering all he has accomplished. And of those three, only one was achieved indoors (Madrid), the usual conditions for fall play.
In fact, Madrid remains Nadal's only career indoor title.
There are some factors to consider when looking at Nadal's lack of autumnal wins over the course of the past few years.
For one, the conditions shifting indoors takes away, to an extent, the damage he does with his biggest weapon, his forehand. The topspin he usually generates on surfaces and conditions more conducive to a lot of "kick" are tempered when playing inside, where the ball tends to stay lower—even with the slower game the pros play today.
Also, players who hit the ball flatter—which is rewarded when playing indoors—can give Nadal more trouble as their shots disrupt his timing. Case in point: At the 2011 World Tour Finals, the last time he played the year-end tournament (he missed last year's event due to injury), Nadal fell in round-robin play to Roger Federer and Jo-Wilfried Tsonga, plus barely edged out Mardy Fish—big hitters all.
That speaks to his troubles indoors, but not all of the ATP stops post-New York are played under the roof, with the events during the fall "Asian Swing" contested outside.
And perhaps, this is where fatigue comes into play.
When healthy—or even when he is struggling with an injury—Nadal puts in a lot of court time as he rarely plays easy points over the course of the year. With the bulk of his winning done on clay, arguably the game's most grueling surface, the amount of time Nadal spends on the court is extraordinary.
Add in the fact that he's likely to play deep into the draw at all of the major tournaments, plus his longstanding commitment to Davis Cup, and you have what can be considered a draining toll on any player.
With his loss to fellow Spaniard David Ferrer in the semifinal of the ATP World Tour 1000 tournament in Paris this weekend, perhaps, some doubt can be cast over the chances of the world No. 1 at the year-end championships starting next week.
That remains one of the few major titles in the game Nadal has yet to claim.
But with no Davis Cup final to play this year in what can be considered one of the best seasons of his career, perhaps the World Tour Finals will be the place for him to turn around his fall tournament-winning deficit.