Rafael Nadal may have won the 2013 U.S. Open title, but Novak Djokovic is still the No. 1 ranked player in the world. The final showed some of their best tennis, and that both players are far ahead of the rest of the ATP tour.
With all four of the 2013 Grand Slam opportunities now completed, there will be one more push for important ATP titles on indoors hard courts at Shanghai, Paris and London's WTF. Some players will show their weariness, but others will seize more energy and rankings points to position for 2014.
It's not enough to simply evaluate the players by their ATP rankings. Which players have played well recently? Who is deserving of being a top 20 player at this moment?