Swiss tennis star Roger Federer will attempt to defend his Masters Cup title at the end-of-season tournament in Shanghai.
But he will be facing stiff competition from the planet's seven other best performers of the year, including his French Open nemesis, Spain's Rafael Nadal.
Federer, who won three out of four Grand Slam events this year, is the logical choice to win his fourth Masters championship in five years. The tournament began on Sunday.
He should be able to progress through the playoff round without too much trouble, given that in his group he will face American Andy Roddick, Russia's Nikolay Davydenko and Chilean Fernando Gonzales. None of these players has managed to find a chink in the Swiss champion's armour this year.
Of the three, only Roddick has ever managed to beat Federer once, but has been troubled by knee and foot problems this season. The Swiss refuses though to pencil his name on the winner's list.
"My first match [on Monday] is against the player [Gonzales] I faced in the final of the Australian Open," he said. "It gives you an idea how tough this tournament is, especially as everyone wants to finish the year well."
Federer likes to point out that the season's eight best players are present and that there are no easy matches.
But one athlete missing from the line-up, Argentina's David Nalbandian, is perhaps the one player who might have really troubled the Swiss. Nalbandian defeated Federer twice recently on his way to tournament victories in Madrid and Paris.
The Swiss isn't concerned by this absence.
"He might have beaten the best players in recent weeks, but didn't make an impact at the grand slam events this year," he said. "Of course I would like to play and beat him, but it's not an obsession for me."
Those defeats might work to Federer's advantage. After losing in Paris, he was able to take a week off, meaning that, in his own words, he is 100 per cent fit in Shanghai.
The Swiss should face a sterner test after the round-robin stage, with Nadal and Serbia's Novak Djokovic looming as potential adversaries. Both of these players have enjoyed success against Federer this year, although the Serb lost his first match in Shanghai against Spain's David Ferrer.
The world number one's rivals shouldn't expect him to throw in the towel anytime soon. Federer repeated this week he plans to play until he is 35, and he is only 26 now even if he has been the planet's top player for the past four seasons.
Whether he will want to continue that long is open to debate though. The tennis world has been shaken by a series of scandals, including possible match rigging and doping.
Davydenko was fined last month for not trying hard enough in a match in St Petersburg, and he has been suspected of losing at least one game in an illegal betting scam.
Italian player Alessio di Mauro was also suspended for nine months on Saturday for betting on tennis matches, becoming the first player to be sanctioned under new ATP anti-corruption rules.
Federer has called for tough sanctions against those who bring the game into disrepute, although he does not believe the best players would get involved with illegal betting.
"There is already so much money around in tennis," he added. "It would be a stupid risk to take."
Federer has also reacted with surprise to the retirement of fellow Swiss Martina Hingis, who was controlled positive for cocaine use at Wimbledon.
"I can't imagine Martina resorting to doping," he said, " she didn't need that. I hope it's not true. In the meantime, she has my support."
swissinfo with agencies
Roger Federer has led the world rankings of the ATP (Association of Tennis Professionals) since February 2004.
In 2007 he won seven titles, including three Grand Slams - Australia, United States and Wimbledon.
The ATP named Federer "Player of the Year" for the third year in a row.
He was Swiss sportsman of the year in 2003, 2004 and 2006.
Federer has been an ambassador for the children's aid organisation Unicef since April 2006.
Date of birth: August 8, 1981
Plays: Right-handed, single-handed backhand
Turned professional: 1998
Titles: 52 (Grand Slams: 12)
Prize money: $36,007,078
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