It’s often said that men’s tennis is deeper and more competitive than it has ever been. And it’s true; the sport has never been played at a higher level. But over the last five years, it hasn’t been the excellence of the ATP as a whole that’s been most impressive. It has been the dominance of the top players despite that depth. Since 2006, we’ve seen three players—Roger Federer, Rafael Nadal and Novak Djokovic—put together seasons that rank among the most gloriously accomplished of the Open era.

Now that the third and perhaps finest of those seasons, Djokovic’s remarkable 2011, is complete, it seems like a good time to look back at where it—as well as Federer’s and Nadal’s best years—fits among the greatest single seasons of the Open era. There’s no right answer, and that’s what makes this parlor game so much fun. Here we present our countdown of the 10 best men’s seasons since the Open era began in 1968.

No. 10: Bjorn Borg, 1979

The Viking God is known for his body of work rather than for a singular season, which is understandable considering that none of them featured a U.S. Open title. But it’s also unfair to a player who had a winning percentage of 90 or higher in four different years. His highest was 93.3 percent (84-6) in 1979. By then, Sweden’s Teen Angel, tennis’ first matinee idol, had evolved into the scarier and scruffier Angelic Assassin. At 23, already with three Wimbledon titles and three French Opens, Borg was at the height of his powers. In ’79, he would add a fourth French and fourth Wimbledon, win his first year-end Masters, and finish No. 1 for the first time. Borg’s only loss of note that year came, under the lights he hated at Flushing Meadows, to a bullet-serving Roscoe Tanner. The next season would bring a new challenger in John McEnroe, but in ’79, Borg left an old one behind. In what may have been his most satisfying achievement, he beat his former nemesis Jimmy Connors all six times they played.

Check TENNIS.com each day for the next season on the list.

Originally published in the Jan/Feb 2012 issue of TENNIS.