'Rafa was just better this year,' says Fed

Roger Federer said he does not regret passing up the chance to topple longtime rival Rafael Nadal from the top of the world rankings at the ATP Finals in London this week.

It could be argued the 36-year-old Swiss has enjoyed a marginally superior year to the Spaniard after winning seven titles, including the Australian Open and Wimbledon.

"Rafa was just better this year. He played more tournaments. He was incredibly successful throughout. So, I don't have any regrets because I feel like in my stage of my competition, my age, either it comes to me or it doesn't," Federer said.