LONDON (AP) - Rafael Nadal describes the ATP World Tour Finals as one of the hardest tournaments for him to win.
But he shouldn't have much of a problem improving on last year's result. Nadal left London a year ago without so much as winning a set in three straight losses in the group stage of the season-ending event.
The 24-year-old Spaniard returns to London after a dominant year in which he won three Grand Slam titles and regained the No. 1 spot.
"When you are not playing well and you don't feel competitive, it's not a nice feeling, but that's part of sport," Nadal said Friday. "It can happen again. Hopefully not, but you're playing the best players in the world in the most difficult conditions of the year for me.
"I'll try my best to change the situation this year."
Nadal sat out the Paris Masters last week with shoulder tendinitis, but says his body is "perfect" ahead of his first match against Andy Roddick on Monday.
The eight-player tournament begins Sunday.
While Roger Federer chases a record-equaling fifth title at the end-of-season event, Nadal is still seeking his first on an indoor surface he describes as "not my specialty."
"If I'm not playing my best tennis, it's almost impossible for me to win matches on this surface," Nadal said. "If it's clay, that changes the situation a little bit: I have more time, more chances. Here it's very difficult.
"The surface here is not very slow, not very fast, it's average, but for me the problem is the bounce. Sometimes the feeling is like the ball is dead. It's easier for me to play well when the ball has a bigger bounce, but that's the conditions."
For that reason, Nadal, who also faces Novak Djokovic and Tomas Berdych in Group A, says his hardest opponent will be Roddick. That's because the American is his first opponent, and Nadal won't look beyond that match.
While the conditions may not be ideal, at least confidence shouldn't be a problem this time around. Since April, Nadal has won seven titles, including the French Open, Wimbledon and the U.S. Open.
Victory in New York made him the seventh man to win all four Grand Slam titles in his career. By September, he had already tied up the year-end No. 1 ranking. Nadal's lead at the top is such that Federer conceded it will be "very difficult" for him to reclaim the top spot next year.
"Last year, it was difficult to imagine doing something like that," Nadal said. "But sometimes the sport changes like this.
"I wasn't playing well last year but I practiced a lot and every day when I wake up, I wake up with the (hope) of changing the situation. That's what I did and finally it changed."
Nadal said the turning point was winning in Monte Carlo, ending almost a year without a title, and then recapturing the French Open title.
"After that, everything was a little less difficult, I played with more calm, more confidence," he said. "Because I won those tournaments, the rest was possible."
Winning the title London's O2 Arena would put the seal on a stellar season. After that, Nadal will have just a short break before he aims at another piece of history. A victory at the Australian Open would mean holding all four Grand Slam titles.