World chess champion Vishwanathan Anand has begun the defence of his title, in one of the most anticipated tournaments in years.
Anand, 43, has won five world titles since 2007. His challenger is Magnus Carlsen, 22, of Norway.
The Indian city of Chennai (Madras) is hosting the event. Twelve games will be contested over three weeks at a hotel, watched by a select audience of 350 inside the main hall and a live television audience.
If their points are equal after the 12th game, there will be a sudden death decider.
The BBC reports many experts expect Carlsen to take the title. Anand has been undisputed champion since 2007.
However, Carlsen, 22, is now the highest rated player in history, with Anand currently ranked only number eight in the world.
Correspondents say the excitement around the tournament is reminiscent of the 1972 clash in Rejkjavik, Iceland, in which US challenger Bobby Fischer ended 24 years of Soviet dominance, beating defending champion Boris Spassky.
"We will see how it goes but I think I am ready to play. I am really excited to play in my home city. I am looking forward to the match starting," Anand told the Times of India newspaper.
Carlsen appeared to downplay his advantage.
"I don't know who the favourite is. In general I expect to do well in tournaments I play in," he said.
Russian former grandmaster Garry Kasparov says Carlsen is the Harry Potter of chess.
Another Russian champion, Vladimir Kramnik, told the Times of India that Carlsen had more energy and motivation than Anand.
"Anand is somewhat intimidated by Carlsen. He has not been confident playing against him - he's scared of him," he said.
However, the BBC reports Anand has won more of their head-to-head matches.
