By winning the 2021 US Open, Novak Djokovic would both lock up the first calendar Grand Slam on the men's tour in more than 50 years and become the first man to ever win 21 Slams in his career.
With his natural athleticism and defensive abilities, Djokovic was destined to become a top-flight tennis player. But he has become perhaps the greatest men's player ever because of his ability to turn the few relative weaknesses in his game into outright strengths.
Here's a look at three areas where Djokovic turned the tables.