KEY POINTS:
Maybe the new Andy Roddick can do it - become an arch-rival of the brilliant Roger Federer. He certainly did it last night, with a 6-2, 3-6, 6-3 win over the Swiss in the Kooyong International, setting tongues wagging ahead of the Australian Open which Federer is supposed to be about to win in his sleep.
But, generally speaking, Federer doesn't have a rival in the traditional sense of some of the great, ongoing clashes of modern tennis.
Like the Pete Sampras-Andre Agassi or Jimmy Connors-John McEnroe contests - matches that would liven up a sport dulled by Federer's greatness.
Roddick is, however, sparking again since he joined forces with Connors as his coach - and last night was his first win over Federer since August 2003. Rafael Nadal is well ahead of the chasing pack and only 810 ranking points separate world No 3 Nikolay Davydenko and Fernando Gonzalez at No 10.
Nadal leads Federer 6-3 in matches between the two since their first meeting in 2004 but there is something of a caveat. The Spaniard has won all four meetings on clay as well as two of four meetings on hard courts.
But it is still difficult to consider Nadal Federer's equal.
Nadal himself recognises this and said last week after being beaten by Xavier Malisse in the semifinals in Chennai: "I don't think I can challenge Roger at the moment. Roger is the best by far. He is at another level. Just look at the numbers, Roger's are so impressive it's just unbelievable."
Of the others, Federer is 8-0 with Nikolay Davydenko, 11-3 against Ivan Ljubicic, 6-0 over James Blake and 12-2 against Andy Roddick. The most competitive is actually Argentine David Nalbandian, with Federer leading their match-ups 8-6 (although Nalbandian won the first five matches in 2002 and 2003). He is also 1-1 with the UK's great hope Andy Murray and 11-7 with Lleyton Hewitt (although Federer has won the last nine).
Famous rivalries
Pete Sampras 20, Andre Agassi 14
John McEnroe 20, Jimmy Connors 14
Bjorn Borg 7, John McEnroe 7
Bjorn Borg 13, Jimmy Connors 8
Bjorn Borg 8, Ilie Nastase 4