It’s been a quartet battling it out for the top spot for some years now, making it arguably the greatest rivalry in the history of tennis.
The sport has been marked by great rivalries over a century ever since Big Bill Tilden and France’s three musketeers – Henri Cochet, Rene Lacoste and Jean Borotra - were concerned in an intense battle for supremacy in the 1920s.
But surely the simultaneous presence of Roger Federer, Rafael Nadal, Novak Djokovic and Andy Murray constitutes the apotheosis of tennis rivalries.
Each of the quartet has had their moments of dominance with longtime No 1 Federer and current No 1 Djokovic having rather extended runs at the exalted position.
But at the moment Nadal, given the ethereal manner in which he is playing, gives every indication of breaking away from the group and taking over at the top, a view that Djokovic has openly expressed.
Beaten in the final at the US Open on Monday, the Serb has also said that the Spaniard has it in him to surpass Federer’s record of 17 Grand Slam titles.
"For a guy aged 27 to have 13 Grand Slams is incredible," said Djokovic after paying handsome tribute to Nadal following the title clash at Flushing Meadows. Verily the sky is the limit for Nadal who has it in him to break all sorts of records.
And to think that he was coming back to competitive tennis after being out for seven months due to knee surgery. The competition being what it is these days at the highest echelons of the sport, a lay off for any duration of time allied to a major operation can mean a steep fall to a lesser mortal. But Nadal is made of sterner stuff.
Just think of it. Nadal was considered a clay court specialist, something that is confirmed by eight French Open titles. But then he proved himself to be more than capable on grass winning two titles at Wimbledon.
But when he came back, the experts all said that the knees would not stand up to the rigours of hard courts. Nadal almost heeded their advice and considered skipping hard court tournaments to protect himself from a recurrence of the knee problem.
And yet since his return, he has won 60 out of 64 matches, 22 of them on hard courts. He has won ten titles, including two Grand Slams. He is currently still at No 2 but few will bet against him rising to the top spot in the remaining two months of the season.
At the moment, then, only Federer and Pete Sampras (14) are ahead of Nadal when it comes to career Grand Slams. The triumph at the US Open took him past Roy Emerson whose 12 majors was the record for a long time and seemed unbreakable till Sampras surpassed it.
For some time now, it appeared that Federer’s benchmark of 17 would stand the test of time. Not any more, not the way Nadal is performing.
Djokovic, who is generally measured in his comments, waxed eloquent about Nadal’s achievements after the defeat on Monday. "Whatever he has achieved so far in his career is something that everyone should respect. He is definitely one of the best tennis players ever to play the game."
If that is the judgment of someone who knows a thing or two about tennis, then one can only imagine to what levels Nadal can reach. For the Spaniard is a ballet dancer, athlete and fighter all rolled into one.
He can be elegance personified even as he bounds from this end of the court to the other to stretch and get to the ball that seemingly cannot be returned. But above everything else he is a fighter. The phrase 'no match is lost till it is won' applies more to him than anyone else.
He has the grit, determination and stamina to battle it out on court like he did during his nearly six-hour final against Djokovic at the Australian Open last year. Incidentally the world No 1 trails him 15 – 22 in their 37 meetings including going down in six of their last seven meetings.
About a year ago, Nadal was almost nowhere in the picture. Federer and Djokovic were dominating the headlines even as Murray came to the forefront strongly by winning the US Open and this year’s Wimbledon.
Nadal missed the last half of 2012 and the Australian Open this year because of the knee surgery but at the moment seems certain to overtake Djokovic as the world No 1 by the end of the year. What a turnabout! Naturally he considers this season to be the most emotional of his career.
First it was Federer – Nadal. Now it is Djokovic – Nadal. But the immensely gifted Spaniard has it in him to break away from the group and make it Nadal – Nadal. Can he make it a calendar Grand Slam next year, something that has not been done since Rod Laver achieved it for a second time in 1969?
Forty five years is a long time and it is a feat that has eluded some of the greatest stars of all time. But the fact that he is one of a handful of players who have won all the four Grand Slams is a good starting point. If anyone can emulate the great Laver, it has to be Nadal in the form of his life.