Novak Djokovic (31, Serbia) is known as a "zero defender" and is a superstar who has divided his men's tennis team with Roger Federer (37, Switzerland) and Rafael Nadal (32, Spain). However, in the first half of this year, the aging of Djokovic seemed to be a fact. Daniel Taro (109th), Martin Klizan (140th) and Marco Cecchinato (72nd), both of whom were at the top of the world rankings at the time, Because he continued to win the consecutive victory. The World Ranking, which has always been the best kept secret, has been pushed to 22nd place by the middle of June.

However, Djokovic made the big game in just six months. After healing the elbow injuries that he was constantly suffering from, he went back to the court and grabbed two Grand Slam competitions, Wimbledon and the US Open. In addition, he has accumulated a huge amount of records in a short time, including two Masters championships and one runner-up. In the final of the Paris Masters on the 4th, Karen Khachanov (22, Russia) lost 22 consecutive walks.

Eventually, in the second half of the game, Djokovic took the top spot in the world rankings at the end of the year. In the men's professional tennis (ATP) singles world ranking announced on June 5, Djokovic ranked first in the year-end ranking as Nadal, second in the rankings, was absent from the final tournament of the ATP Finals. It is the first time in the history of ATP tour that he is in the top 20 in the world rankings and is the first player to finish the season.

Federer and his rival had to stand side by side in the number one ranking at the end of the year. Djokovic finished the top of the world rankings in 2011, 2012, 2014 and 2015. Federer and Jimmy Connors were in the top five in this year, adding another year to the list. Pete Sampras, who is the No. 1 ranking holder in the year-end ranking, once again pitched a one-time gap in the sixth inning and reopened his way to the top tennis player of all time.