Another Tie - Kasparov vs machine chess series ends

World number one chess player Gary Kasparov's latest attempt to conquer a computer program has ended in a tie.

He drew the fourth and final game of his match against X3D Fritz, which had voice-recognition and virtual reality features.

Kasparov, 40, said after the week-long match at the New York Athletic Club that computer programs were stronger now than the IBM supercomputer Deep Blue he took on in 1996 and 1997, the benchmark for man vs machine contests.

"Machines are getting better but we humans are also learning," said Kasparov, considered by chess experts to be the best player in the history of the ancient game.

"Today, I know much more about computers than six years ago."

The grandmaster and the computer's programmers agreed to a draw in the fourth game after about 90 minutes and just 27 moves, the shortest game of the series that began with a November 11 draw.

X3D Fritz won the second game when Kasparov blundered. The grandmaster won comfortably on Sunday.

In February in New York, Kasparov tied a six-game match 3-3 with Israeli-built world chess computer champion Deep Junior.

A version of German-built Fritz tied an eight-game match 4-4 last year with world champion Vladimir Kramnik of Russia.

Azerbaijan-born Kasparov lost his world title to Kramnik in 2000 but is still rated number one in International Chess Federation rankings.

X3D Fritz is a combination of Fritz software that is sold commercially and the New York-based X3D Technologies company's virtual reality software.