NEW YORK -- When defending champion Gary Kasparov, 27, makes his first move in the World Chess Championship at 5:30 today, he will already be a winner. What he won was the right to make his own decisions on how and when he would defend his title. And the opponent he defeated was even more formidable than Anatoly Karpov, 39, against whom he will be playing the 24-game championship match -- it was the International Chess Federation (FIDE), which has controlled the world championship since the end of World War II and which Kasparov has publicly called a "mafia."

With that battle settled, Kasparov can now settle down to other struggles:

Against Karpov, whose score is still uncomfortably close to Kasparov's after nearly 150 games played in the last five years: 19 wins for Kasparov, 17 for Karpov, the rest drawn. This time, Kasparov says, he hopes to win "decisively."

Kasparov is built like a prizefighter, and there is a menacing aura about him when he comes into a room, not unlike that of Muhammad Ali in his prime. Karpov, small, pale-complexioned and inclined to be quiet, contrasts sharply with his opponent in physical appearance but has held his own in their prolonged chess struggle. The last championship match, three years ago in Seville, ended in a draw, which meant that Kasparov kept the title.

Against communism and the crumbling remains of the Soviet Empire. Karpov will be playing, as usual, with the red-and-yellow Soviet flag displayed on his side of the table. Kasparov's flag will be the red-white-and-blue one of the Russian Republic. "It is not an official flag yet," he said here in a press conference held jointly with Karpov. " ... I am doing this to show my moral solidarity with my compatriots ... protesting the government."

Kasparov is a founding member and the deputy chairman for foreign affairs in the Democratic Party, a group opposing Mikhail Gorbachev's government. Karpov, a Communist and a deputy in the Soviet parliament, considers Kasparov an extremist and tries to dismiss the political overtones of the match. "I am here to play chess. Possibly someone will play politics," he said at the press conference. "It is indifferent to me what flag Mr. Kasparov plays under."

Against time and technology. Although he has easily defeated a computer chess program called Deep Thought and billed as the world's strongest, Kasparov has slowly come to the opinion that he may be the last human world chess champion. He claims (and the record seems to support his claim) that he can defeat any computer he is likely to face in the next five years and probably until the end of the century. And after that? It would be "unpleasant," he says, to think that "a machine can conquer the human mind." But he thinks it may happen.

Against the haunting memory of Bobby Fischer, whom he never played but who remains his primary opponent on the imaginary stage of chess history.

The preliminary battles in a world chess championship are often as interesting as the games themselves. This time around, the main preliminary was Kasparov vs. FIDE -- specifically FIDE President Florencio Campomanes -- and the primary issue was whether the match would begin in Lyons, which had been chosen by FIDE, or New York, Kasparov's choice. If he did not accept Lyons, Kasparov would be eliminated from the world championship, FIDE decreed. Who will pay any attention to a championship match without the world champion? Kasparov replied. What's more, he got his four challengers to agree and sign a joint statement -- a demonstration of solidarity unusual among grandmasters, who tend to be a rambunctious, individualistic lot.

Kasparov's grudge against FIDE and Campomanes dates back to his first match against Karpov in 1985. Campomanes stopped that match, citing health reasons, after 48 games when Karpov was still ahead but fading fast. Since then, Kasparov has founded a second international chess group, the Grandmasters' Association (GMA), been elected its president and set it up in more or less open rivalry to FIDE. The most noted effort of the GMA so far has been the World Cup competition, a series of spectacular tournaments played in 1988-89, involving the world's 24 top players in more than 1,600 games for prizes totaling more than $1 million. Kasparov won that too, with Karpov close behind.

The championship match (the fifth between these players) is scheduled to run a maximum of 24 games, and will have a top prize of $1.5 million. The first 12 games will be played in New York on Mondays, Wednesdays and Fridays through Nov. 10 (if all goes smoothly, as it probably will not). Games will begin at 5:30 and run for a maximum of five hours; unfinished games will be resumed the next day.

After the first 12 games, the match moves to Lyon, beginning Nov. 24. Having established his rights on this issue, Kasparov was willing to make concessions to Lyon, whose mayor is a personal friend. The French city cannot be sure how many games will be played there, if the match does not run its full length, but it will have "the decisive half" of the match, Kasparov observed.

The New York half, sponsored by entrepreneur Ted Field, will be played in the 650-seat Hudson Theater in the Hotel Macklowe on West 44th Street. Ticket prices were originally set at $100 each, but economic realism set in and there are now tickets for $50 and $25 as well. A ticket for the entire series in one of the best seats sells for $1,000. Kasparov, who at one point said he would not play if Campomanes was present, has relented slightly -- jokingly, he has said that Campomanes can come if he buys his ticket.

One of the triumphs dearest to Kasparov's heart took place last year against an opponent he has never played: former champion Bobby Fischer, who forfeited his title when he did not show up to defend it against Karpov in 1975. In the rating system that assigns numbers to chess players according to their strength, Kasparov reached 2795 last year. This was the highest rating in the history of the game and, more important, it passed Fischer's life rating of 2780. Kasparov is proud of this but does not feel that it is the same as if he had beaten Fischer in an actual match.

The important element is "the distance between a champion and his opponents," Kasparov insists, and so far he has not outdistanced his challengers as spectacularly as Fischer did the other players of the early 1970s. As they head into their fifth world championship match, Karpov and Kasparov are still, jointly, a comfortable distance ahead of all the world's other players, but only a microscopic distance apart. Between now and the end of the year, Kasparov and Karpov both hope to terminate that situation.

Grandmaster Lubomir Kavalek contributed to this article.