Is it conceivable that in one generation there could be three male players all potentially vying for the title of the Greatest Of All Time? I think it is. This is unique in tennis history. Only one other era: the mid-1970's-early-1980's when Jimmy Connors, Bjorn Borg and John McEnroe all made a bid for the GOAT; has there ever been a span of ten-years-or-less that produced three historic players like the present one. Roger Federer, Rafael Nadal and Novak Djokovic have either made their claim or are in the process of sealing the deal on being crowned the GOAT.Federer, is generally perceived to be the GOAT today with a record 16 slams. He was No. 1 for 285 weeks, has won 782 matches and 67 tournaments. Nadal is making a strong push for the GOAT. The Spaniard is nearly five years younger than Federer and already has won 10 slams, 523 matches and 46 titles. Nadal also holds a decided advantage in head-to-head matches with Federer and was No. 1 for 102 weeks in total until Djokovic usurped the top spot by beating Nadal five times in a row in 2011, all in Masters finals except for his Wimbledon disposal of Nadal. Djokovic at 24 has come alive this year, going 48-1 in 2011 with two slams already, a semis at the French, and eight titles. He is the current No. 1 player and has won three slams, 372 matches and 26 titles. Pete Sampras was considered the GOAT until Federer upended him a few years ago. Sampras won 14 slams, 762 matches and 64 titles.It is not ridiculous to postulate that by the end of the 2013 season, just nine slams in span, the GOAT debate will be safely settled. If Djokovic wins five of those nine slams, which I believe he will, he will be up to 8. Nadal could be at 12 or 13 by then. Federer could still eke out another slam. But if Djokovic wins seven of the next nine, not out of the question in my mind, I think he can be well onto his way to becoming the GOAT if he were to add another five slams from 26-30. If Djokovic ends up winning 14 slams to go along with a long stint at No. 1, along with Davis Cup triumphs, and the key fact that he took down both Federer and Nadal, he goes down in my book as the GOAT. And what a career-change that would augur.