At 33, Roger Federer continues to impress

For a player described as a spent force a year ago, Roger Federer is proving he still has it.

After a disappointing 2013 campaign that he finished with a modest 45-17 record, the 17-Grand Slam champion enjoyed a superb resurgence this season, losing to the top-ranked Novak Djokovic in an epic Wimbledon final and adding five new titles to his collection.

On Tuesday, Federer posted his 70th win on the Tour this year -- the most by any player this season -- with a clinical 6-3, 6-2 success against Japanese newcomer Kei Nishikori at the ATP Finals.

"I think it's a great number," said Federer, who, at 33, is about to become the oldest player to finish a season in the top two.

Federer remains on course for the year-end No. 1 spot, but his fate is not in his own hands anymore as Djokovic will nail it if he wins his next two round-robin matches in London.

"Novak looks great. For me, it was never the goal to win World No. 1. My focus is rather to try to win the World Tour Finals here and then play a good (Davis Cup) final next week," Federer said.

"The rankings anyway are going to follow or not. I'm just pleased that I'm winning my matches right about now."

Federer slipped to No. 7 in the rankings last season after losing in the second round of Wimbledon and the fourth round at the U.S. Open. He claimed only four wins over top 10 opponents and was hampered by lingering back problems.

With his back fixed and new coach Stefan Edberg on his side, Federer adapted to a new racket and made some adjustments to his game, coming more often to the net than in previous years.

The changes paid off.

The Swiss made it to the semifinals at the Australian Open and the U.S. Open and won his 23rd Masters title in Shanghai last month.

"I never feel that he's 33 right now," Nishikori said after his loss at the O2 Arena. "He still looks young and is playing amazing tennis. I think his age doesn't matter right now."

After the ATP Finals, Federer will be chasing the only major trophy still eluding him, the Davis Cup.

Teaming up with Stan Wawrinka, he will travel to Lille to take on the French from Nov. 21-23.

A victory in the team competition would not only cap a successful year for Federer, but also arguably put an end to the "greatest player ever" debate.

"We all know that it's very difficult to win Davis Cup because you don't win it by yourself," said Djokovic, who won it in 2010 with Serbia, against France. "It's a team effort. So I'm sure that he's going to be having plenty of motivation to do so."