IT is the sport that reverberates with superlatives.

Roger Federer? The greatest player ever? Rafael Nadal? The King of Clay. Novak Djokovic? The hero in the most superb individual season in tennis. Andy Murray? The best player never to have won a major.

And here is the clincher. The 2012 season? The toughest year ever in tennis for the top players.

The four Grand Slams this year will be complemented by the Olympics in London in July. The players, already buckling under the strain of an 11-month season, must now insert what can be termed as another major between Wimbledon and the US Open. This adds intrigue to a season that frankly does not need it because the superlatives that accompany the players are consequently followed by question marks.

Federer may be the greatest of all time but can he win another major? Can Djokovic repeat his spectacular year? Will Nadal's reign continue? And will Murray finally win his Grand Slam? The answers are yes; no; yes and no; and who knows.

Federer has at least a viable chance of adding to his haul of 16 Grand Slams. His victory in the Barclays ATP World Tour Finals was greeted with almost hysterical acclaim but it must be remembered that this tournament is not a reliable indicator of the season to come. Nevertheless, Federer, at 30, is still a formidable opponent who knows his way through a Grand Slam fortnight. His vulnerability is that now not one of the other top players truly fears him and that a big hitter of the stature of Jo-Wilfried Tsonga, Tomas Berdych or a resurgent Juan Martin del Potro has the capacity to hit the ball through him. His strengths, however, suggest there is still a major left in him.

The answer to the prospects of Djokovic repeating 2011 is a considerably more straightforward no. The Serb had the most outstanding season ever and it would be optimistic to expect him to do it all over again. He is the overwhelming favourite, though, to maintain his status as world No 1, starting this month with the defence of his Australian Open title.

Djokovic has gained an extraord-inary confidence over the past 12 months. His forehand on a Federer match point at the US Open was one of the moments of the year and testified both to his technique and his belief that borders on arrogance and can provoke shots that would be described as reckless if they did not prove to be winners.

Any mention of the Serb brings an image of Nadal to mind. It is of the Spaniard sitting at the post-final Wimbledon press conference and admitting he had a psychological prob- lem with facing Djokovic. It was not exorcised at Flushing Meadows where Nadal was again beaten by Djokovic for the sixth time in a final last year.

It is becoming increasingly diff-icult to picture the circumstances that would favour the man from Manacor over the world No 1. There will be the immediate protest that Nadal should prevail at Roland Garros but supporters of Djokovic will point out that the Serb won the two finals on clay – in Madrid and Rome – contested between the pair in 2011. Nadal remains an early favourite for the French Open, but only just.

And what of Oor Andy who will play in the Brisbane International on Tuesday as he begins his quest to go one step further and win an Australian Open?

One is alternately bemused and amused by those who insist with equal volume that Murray will or will not win a major. The rather humdrum truth is that no-one knows. He has the game to win a Grand Slam and he has beaten all of his rivals in the past. But can he stretch seven match-winning performances together over a gruelling fortnight, probably having to overcome two of the best players ever in that sequence?

The 24-year-old Scot has reached three major finals, and was beaten in straight sets in all of them, twice by Federer and by Djokovic last year in Melbourne. He may need some fortune to make his breakthrough, even the great players do. Federer opened his major account with victory over Mark Philip- poussis, Djokovic against Tsonga, and Nadal against Mariano Puerta.

The Olympics at Wimbledon, where he should be joined as a singles competitor by his compatriot Elena Baltacha, may just be the opportunity for Murray to win very big and then go to Flushing Meadows with confidence.

A swell of patriotic fervour carried Djokovic to a Davis Cup final victory in 2010 and prepared the way for his wonderful year and it prompts hopes that a home Olympics could have the same inspirational effect on Murray.

It will be hard for the Scot during the hardest of seasons. A major victory would, however, lighten the load on his shoulders.

Fab Four facing hardest of seasons

Andy Murray will hope to win his first Grand Slam this year Photograph: Getty

Hugh MacDonald