The ATP Finals begins in London on Sunday, with the top eight healthy men in the world set to compete for the prestigious year-end title.
The top two seeds at this year's championship are as familiar as it gets. Rafa Nadal enters the tournament as the top-seed and will end the year as the No. 1 player in the world no matter his results in London. Nadal, who won two majors this season, is making his 13th consecutive appearance at the Finals, and while he has reached the final twice—in 2010 and 2013—he is yet to win the title.