S PORT is the ultimate numbers game, but it prospers because of personalities.

Much of the post-match comment on Andy Murray's three-set defeat by Novak Djokovic will linger on the Scot's failure to take any one of the five match points offered to him in the second set. However, the match has a more substantial significance for the world of tennis than any stumble on behalf of the world No.3.

The ATP site yesterday stated the importance of Djokovic's victory in sustaining the race between the Serb and Roger Federer for the year-end world No.1 spot, but the events in Shanghai point to a growing realisation that the numbers game has become drastically altered. As recently as June, it was possible to state without inviting any loud protest that the Big Three of Federer, Djokovic and Rafael Nadal had moved clear of Murray. A reiteration of this belief four months on would bring howls of derision.

The spectacular match yesterday instead raises the question: is this the rivalry that will sustain tennis in 2013 and beyond?

The Murray-Djokovic dynamic has erupted on the tennis world with a dramatic suddenness. They first played each other at 11 years of age and have been constantly compared by commentators ever since. Yet, now 25, they have only played each other 16 times in top-class tennis. The major reason for this is their perennial roles as the backend of the four-legged ATP horse. The Nadal-Federer axis dominated at grand slams and Murray and Djokovic played to what were their rankings of No.3 and No.4.

As Murray and Djokovic now vie for favouritism for the next grand slam in Australia, it is perhaps instructive to see why their mano a mano tussles at the business ends of tournaments have been limited. Federer has a 16-12 advantage over Djokovic in head-to-heads and Nadal leads Murray 13-5 in that match-up.

However, that superiority is fading and may be a matter of historical record rather than a portent of the future. Any projections about the propensity of the Spaniard to return to the top of the game must be made with an industrial dose of caution. As Federer has justifiably been lauded as the greatest player of all time, Nadal has been curiously under-valued. The truth is that his record against the Swiss player is overwhelming in his favour with an 18-10 winning record bolstered by an 8-2 advantage in grand slam tournaments. Incidentally, Nadal leads Djokovic 19-14.

But the Spaniard, at just 26, is confronting a serious threat to his career. Tendinitis in his knees has kept him away from competitive tennis since Wimbledon and he is unlikely to play again in 2012. This would mean he would arrive in Melbourne after a long absence from competition and with his rivals progressing, becoming stronger in the interim.

There is also a doubt, though a less substantial one, hanging over Federer. At 31, he continues to make the right noises about his focus and desire and is still No.1 in the world despite losing in the Shanghai semi-finals to Murray. This means the Scot has taken five straight sets from the Swiss player after he defeated him in the Olympic Games. Federer cannot be dismissed, but Murray, who leads the 17-time grand slam winner 10-8 in their match-up, has never feared him and Djokovic has escaped the chains that used to restrict him when facing the "greatest of all time".

The prospect of Djokovic and Murray reprising such battles as the Olympic semi-final match, the US Open final and yesterday's Shanghai final now increases.

It is an intriguing, fascinating scenario. The Scot will rue missed chances in Shanghai, particularly as another victory over his friend would have added strength to claims that he was gaining a superiority over the Serb. However, this ignores the reality that Djokovic is a multiple grand slam winner and has reacted to the US Open defeat with 11 straight victories, in Beijing and now Shanghai.

The only slight surprise of a tight match was Murray's inability to win a tie-break. ATP figures show he is the second best on tour at winning shoot-outs. Curiously, Steve Darcis of Belgium is the best. But enough of figures. The Murray-Djokovic drama is about action and it has been of a high quality at Wimbledon, Flushing Meadows and Shanghai.

Both players now seem free of the nervousness that once constrained them. Djokovic's contribution to Serbia's 2010 Davis Cup victory gave him the belief to embark on the greatest year in tennis history. Murray's Olympic gold gave him the faith to prevail in New York.

The depth of the tennis tour ensures that both can be beaten on a given day by anyone inside the top 20, but grand slam tournaments demand seven victories in 14 days. Increasingly, Djokovic and Murray look the strongest players in terms of endurance, belief and strokes. Their matches are often referred to in boxing terms because of their relentless aggression and their punishing physicality. Their last eight sets have taken roughly eight hours. In boxing terms, neither has the other's number. But, again in the parlance of the ring, they show that styles make fights. They are scheduled to be the main event of 2013.