Novak Djokovic is on the verge of retaking the world No. 1 ranking. It seemed impossible at the start of the year.  In March when the Serbian was unceremoniously dumped out of the first round in Indian Wells and Miami.

Ranked No. 22 in June, Djokovic's resurgence took an aggressive turn for the better. He would win Wimbledon, Cincinnati, the US Open and Shanghai. Only 215 points now separate the 31-year-old from Rafael Nadal's No. 1 ranking, and Djokovic is in the perfect position to reclaim it. With no points to defend until the end of the season, the year-end No. 1 ranking looks like it's Djokovic's for the taking.

If he does become world No. 1 after Paris, it could still flip back over to Nadal at the ATP Finals in London. What do you think of Djokovic's chances?