Djokovic is third on this list, but no one is shooting up the Slam ladder with more speed and gusto. At 28 years old, does he have enough time to catch Nadal? And ultimately Federer?
The Serb should enjoy the pinnacle of his career for at least another couple of years, but keep in mind, he turns 32 in three years, and only three players have won a Slam title in the Open era after that age.
As for Federer, although he failed to win a major title, he did secure his spot as Djokovic's main rival, falling to the world No. 1 in the Wimbledon and US Open finals. Federer handed Djokovic three of his six losses in 2015.
The question is: Can Federer finally take the next step and win a major, something he hasn't done since 2012?
He's 34 years old; no men's player has won a major at that age since Andres Gimeno in the 1972 French Open.
No matter what happens, the Big Three has created an unmovable stranglehold in the game for a decade.
The greatest era ever? Hard to argue against it.