After Mr Kasparov's opening move (Pawn to E-4) in New York on Monday, he travelled to Washington, DC, where users guided by four young chess experts initiated the 'Sicilian Defence', moving pawn to C-5.

Thousands of chess enthusiasts have taken up the online challenge, dubbed "Kasparov vs the World".

Microsoft's Gaming Zone, the Web site acting as host of the tournament, registered more than 2 million hits for the day, according to a spokesman.

The World Team's first move was chosen by 41% of those voting.

Kasparov declined to make another move in order to maintain the "suspense," said Audrey Waters, Kasparov's spokeswoman. He has 24 hours to respond.

Quality 'will be high'

In the past, he has played up to 45 amateurs simultaneously in separate games, but he told the BBC the quality of those games is generally very low.

In this game, chess players from around the world vote on the next move.

"Here, I have a bunch of amateurs. 99% of the team is not very strong, but if you add computers and the advice from the coaches, you'll get a pretty decent opponent. The quality of the game will be pretty high," he said.

Computers and chess

Kasparov: probably the strongest chess player ever

Mr Kasparov said computers had dramatically improved his preparation over the last few years.

"With computers, with the chess software, we can do in a half hour what I normally did in six hours 10 years ago," he said.

The four young experts heading the team against Kasparov are grandmaster Etienne Bacrot, 16, from France; American Florin Felecan, 19; US women's chess champion Irina Krush, 15; and German Elisabeth Pahtz, 14.

Mr Kasparov is widely regarded as the greatest chess player ever. He has been particularly strong over the last few months with three convincing tournament victories in a row.

In 1996 and 1997, he played two six-game matches against the Deep Blue, winning the first and losing the second.

Millions of Net users are believed to have followed those games.