Djoker wearing broadest of smiles

Just as the world's greatest players have their signature shots, so too do they possess a trademark expression. Rafael Nadal employs that inquisitive, almost puzzled curl of the eyebrow.

Andy Murray usually wavers somewhere between a grimace and a glower. Roger Federer? Simply tears. But of late, more often than not, Novak Djokovic is a portrait of self-contentment grinning the broadest of smiles.

The Djoker is happy again. His delighted countenance hasn't always been on show this year but he begins the Barclays ATP World Tour finals as not only the form player, with titles from his past two tournaments and notable wins over Federer and Nadal, but also as the defending champion.

For the first half of 2009 he appeared confused, determined to mask his exuberant personality as a joker and mimic with a more serious and reserved approach. Such decisions are not unusual for somebody still trying to find his path in life, and Djokovic is just 22.

Like many extroverts, he wanted to be funny when it suited him and not when anybody demanded a little levity. He ditched his impressions of players such as Andre Agassi, Federer, Nadal, Murray, Andy Roddick and Maria Sharapova.

Number of reasons

No longer was he prepared to be the centre of attention at every extracurricular photo opportunity arranged for the top players. It was time for the new Novak, for somebody intent on letting his tennis do the talking and take precedence over all the tomfoolery.

"For a number of reasons, I purposely shut the door on all that stuff," he says. "I wanted people to see that all my life I had been serious and disciplined about my tennis, even if I enjoyed the things off the court that seemed to make people laugh. I thought I could achieve more if it was simply serious stuff and all focused on the tennis, but it didn't work out because that wasn't me at all."

Three factors led to his change in demeanour. First was the negative reaction to his politics after he emphasised his solidarity with rioting Serbs, who attacked the United States embassy in Belgrade last year in anger at Western support for Kosovo's independence.

Djokovic felt his stance was justified because most Serbs regard Kosovo as their religious and cultural heartland and the majority of his family hail from the disputed territory, but now it is a subject he refuses to discuss.

Then he was booed off court by a 23,000-strong crowd at Flushing Meadows after using a post-quarterfinal interview to berate Andy Roddick for comments the American made in jest about a perceived Djokovic catalogue of ailments.

Finally, and with some irony, there was his inability to finish January's Australian Open quarterfinal against Roddick when heat exhaustion in temperatures touching 36C led to cramp and forced Djokovic to relinquish the title.

Learning curve

"Everybody makes mistakes and I made many," he says. "I'm well aware of that. I have been through a lot of emotions but I have learnt, so in that respect I have been fortunate. Right now my hair is still black but it should be white after everything I went through."

Djokovic is one of the more intelligent players on tour. His English is grammatically perfect and his vocabulary puts many to shame, but in addition he can also converse in Italian, German and French as well as his native Serbo-Croat.

He reads avidly on a variety of topics, keeps abreast of world events and this year was the driving force behind his family setting up a tournament on the ATP World Tour after buying the rights to the faltering Dutch event in Amersfoort and relocating it to Belgrade.

"To me, this end-of-year event is second only to the four Grand Slams," he says. "I was not at all happy with the way I finished in Melbourne. Now I've put all my troubles behind me, my game is good again, my confidence is high and London is a great tennis city with the best traditions. It all points in the right direction."