Novak Djokovic played in the finals at all nine tournaments.
Novak Djokovic . Djokovic has won 12 Grand Slam singles titles , the fourth most in history , and held the No. 1 spot in the ATP rankings for a total of 223 weeks . Djokovic 's records include breaking the single-season record with six masters titles in 2015 , winning 31 consecutive ATP World Tour Masters 1000 series matches , playing in the finals at all nine ATP Masters 1000 tournaments ( shared with Roger Federer and Nadal , and being the only player to win eight of the nine events ( and at least twice ) .