Man and machine have taken equal honours in the eight-match Brains in Bahrain chess duel.

World champion Vladimir Kramnik of Russia tied 4-4 with the chess computer Deep Fritz.

Kramnik won $800,000 for his part in the tournament, awarded by Bahrain's King Hamad.

For his opponent, publicity for the computer manufacturer Chessbase is the most obvious benefit.

Kramnik: "Totally exhausted"

Had Kramnik won, his prize money would have been $1m.

But at least he exceeded the performance of his predecessor as world champion, Garry Kasparov, who in 1997 was defeated by supercomputer Deep Blue in New York.

Fatigue takes over

Kramnik told reporters after the match: "I'm not especially satisfied with the result even though I had more chances to win than the computer."

Deep Fritz, with Black, opened with what the chess champion called a "clever choice" - a Queen's Gambit.

I was in no danger of losing

Vladimir Kramnik

"I was not prepared for this particular line. If you can't catch the computer out of the opening, it's hard to do anything," he said.

By the time Kramnik offered the draw, he had used an hour and a half while Deep Fritz had only used 25 minutes.

He complained of sleeplessness the night before:

"I felt totally exhausted," he said.

Changing fortunes

Kramnik started the tournament by dominating the first few games, winning games two and three, and never appeared in any danger.

Humans will always have more attacking opportunities

Mathias Feist Deep Fritz programmer

During early games, Kramnik found a way to exploit the playing style of the computer and frustrated its ability to look ahead and predict which way a match was going.

But then he made an elementary blunder in a difficult position to lose game five.

He then resigned in game six, in a position that some analysts thought was still tenable.

Deep Fritz, a German-developed computer, can evaluate 3.5 million moves per second.

So Kramnik was allowed to practise against it for two weeks before the contest.

The Russian was crowned chess world champion in 2000 when he beat Kasparov, his former tutor, in London.