LONDON, Sept. 6— With their breakaway world championship ready to get under way on Tuesday, Gary Kasparov of Russia, the champion since 1985, is a heavy favorite to defeat the challenger, Nigel Short of Britain. But chess history is littered with upsets.

Mr. Kasparov, regarded as possibly the best player of all time, has won 10 games against Mr. Short and lost only one. He concedes he may lose some games this time, but not, he insists, the match.

"I think I can retain the title for the next six or seven years," the 30-year-old champion said on BBC television.

Mr. Short, at 28 Britain's strongest-ever chess player, is undeterred by the underdog label. "I don't think he'll find it anywhere near as easy as he imagines," he told the BBC. Upsets in the Past

If Mr. Short looks back over chess upsets of the past, he can draw hope from the 1935 world championship, when Max Euwe of the Netherlands defeated Aleksandr Alekhine, among the greatest of Russian champions, and from the 1927 title match, when Alekhine, then the underdog, outlasted Jose Raul Capablanca, thought of at the time as invincible.

Mr. Short has already defied the odds by defeating the former world champion, Anatoly Karpov of Russia, in the semifinals. Along the way he also defeated the strong Dutch grandmaster Jan Timman. Mr. Karpov and Mr. Timman are playing a match in the Netherlands under the flag of the International Chess Federation, or FIDE, the long-time overseer of world chess. Mr. Kasparov and Mr. Short broke with the federation when they got the support of Rupert Murdoch's Times of London and set up the Professional Chess Association as a FIDE rival.

Mr. Kasparov and Mr. Short say there is no question that the public will recognize the winner of their match as world champion. "The world championship match is not about the quarrel, or about the fight between two organizations," Mr. Kasparov said. "It's just about the best chess player on the planet." More Attention, More Money

The Kasparov-Short match has attracted more attention in the news media and more prize money than the FIDE match, $2.55 million to $1.38 million.

But FIDE insists that only its winner can be world champion, a view supported by some players.

"If one wants to be absolutely formal, the world champion must be the winner of the Karpov-Timman match, much as one would dislike it," said the British international master William Hartston. "Other sports have had world champions who haven't been the best player in the world."

Expressing a view shared by many players, he conceded, "The world of chess is in a mess." -------------------- KARPOV WINS FIRST GAME

ZWOLLE, the Netherlands, Sept. 6 (AP) -- Mr. Karpov captured the opening game from Mr. Timman today in the FIDE championship match.

Mr. Karpov, playing with the black pieces, called on the Caro-Kann Defense and won when Mr. Timman resigned on his 57th move.

Shortly after the start of the match, FIDE's president, Francisco Campomanes of the Philippines, condemned the rival match between Mr. Kasparov and Mr. Short.

"There's been a cancer and this is just an excision," Mr. Campomanes said at a press conference, referring to his organization's stripping both players of their ratings.

Mr. Timman and Mr. Karpov appeared calm and relaxed, and the first game began on schedule after Mr. Karpov had cleared up a problem with his chair, which he said was too high off the floor. THE CHESS COLUMN

During the match between Gary Kasparov and Nigel Short, the Tuesday chess column by Robert Byrne will not appear. The column will resume after the match.