Who is number one in Men?
Novak Djokovic is guaranteed to overtake Roger Federer in the rankings and finish 2012 as world number one.
The Serb lost his top ranking to Roger Federer after the 31-year-old Swiss player won Wimbledon.
But Federer will not defend his Paris Masters title, after which Djokovic will return to number one.
His absence means Djokovic will take an unassailable rankings lead ahead of the season-ending ATP World Tour Finals on 5 November.