"You can imagine," he said. "I don't know how on an emotional level it affects me."

Anand's victory was not a surprise -- he is ranked No 1 in the world -- but it was a milestone. He is the first Asian to be the undisputed champion and only the second from outside Eastern Europe in the last 60 years. Anand will not have a lot of time to rest on his laurels. Under rules of the World Chess Federation, the organisers of the championship, he must play a match early next year against the Russian Vladimir Kramnik, the previous champion.

While they are facing off, Veselin Topalov of Bulgaria, another former champion, will play the winner of a tournament to be held this year in Russia. The winners of those two matches will play a final match to determine a new champion.

Anand's strength has always been his speed and computational ability. He quickly sees deeply into positions, rarely spending much time on his moves or using anywhere near his allotted time for a game.

For many years, he has widely been acknowledged to be the best rapid chess player in the world.

Anand, 37, took a long time to win the championship. He broke into the elite in 1991 by winning a strong tournament that included Garry Kasparov, then the world champion, and the former champion Anatoly Karpov.

Since then he has won all the top tournaments at least once, but he has always struggled to win matches. In a match, the historical format for determining a champion, two players face each other repeatedly, while in a tournament, many face one another just once or twice.

Some observers and fellow competitors have ascribed Anand's struggles in matches to nerves. In 1995 he lost an 18-game match at the top of the World Trade Center to Kasparov. In 1998, he won a tournament to select a challenger to Karpov for the World Chess Federation championship; they played to a tie in a six-game match, but Karpov prevailed in a playoff.

Second world title
Technically, Anand's victory in Mexico City is his second world title. In 2000, he won the federation's championship tournament held in Tehran and New Delhi. But at the time, the title was split and many people recognized Kramnik, the Russian, as the legitimate champion, a situation that Anand acknowledged tainted his victory. Anand lost the federation title in 2002, failing to win a championship tournament in Libya.

Last year Kramnik became the undisputed champion after he beat Topalov in a match in Elista, the capital of Kalmykia, a remote Russian republic.

In Mexico, a tournament, Anand outdistanced seven of the world's top 14 players, including Kramnik, emerging as the only undefeated player.

He is now the undisputed champion, acknowledged even by Kramnik, but since his victory some fans have said on the internet that he cannot be considered a true champion until he proves his mettle in a match. So the match against Kramnik will be important.

Anand said that Kramnik and Topalov, who did not play in Mexico City, should not have been given "special privileges" to try to reclaim the championship in the coming matches, but, he added, "It is water under the bridge."

In the modem era, it is unusual for a champion to be so old - in his late 30s - raising the possibility that Anand's reign may be short. He said that while the top players are getting younger, he also noted that the top three in Mexico City - himself and the two who tied for second and third, Boris Gelfand, 39, of Israel, and Kramnik, 32 - were also the oldest. "Maybe a bit of experience didn't hurt," he said.

Anand said he did not know how long he would play competitively, but he drew a clear line.

Referring to Viktor Korchnoi, a former world championship challenger, who is 76 and continues to play regularly in tournaments, Anand said, ''You can rest assured that I won't be doing a Korchnoi."

International Herald Tribune