The ATP World Tour Finals—the season-ending championship of men's tennis—begins on Sunday, November 9 in London. Over the next four days, we'll take a closer look at the seasons put forth so far by the eight singles competitors.

Like Don Draper in "Mad Men," it was a grim 2013 for Federer. But both well-dressed men turned things around this year. On a week-to-week basis, no one was more consistent than Federer, who won 68 matches—the most on tour—and in 16 tournaments only twice failed to reach the quarterfinals. He suffered straight-set semifinal losses at the Australian and U.S. Opens, and was unable to add another Wimbledon title to his collection, but for the 33-year-old, it wasn't all about the majors—so much so that, depending on his finish, this year might be considered one of the best of his career. Where does he go from here? Like the fate of a certain ad executive, we’ll have to wait and see.

With five titles and a run to the Davis Cup final, there are many to choose from, but Federer's comeback from two sets down against Gael Monfils at the U.S. Open stands out. With Arthur Ashe Stadium buzzing and at full bellow, the sport's biggest star saved two match points in a contest that will live in the canon of the Open's night classics.

Each of Federer's late-round major losses were tough in their own way, but losing the fifth set of a Wimbledon final is in a class of its own. The seven-time champ did well to force a decider, but couldn't sustain the momentum that took him there.

Advertising

Like Novak Djokovic, the No. 1 ranking. Considering Federer's age and that he didn't win a Slam this year, the achievement would be all the more impressive.

ATP World Tour Finals Previews

November 5: Marin Cilic

November 5: Roger Federer  
November 6: Novak Djokovic  
November 6: Milos Raonic  
November 7: Andy Murray  
November 7: Stan Wawrinka  
November 8: Tomas Berdych  
November 8: Kei Nishikori