His brash moves on and off the chessboard already have made 22-year-old Gary Kasparov the hottest star in world chess.

Now, as his match against titleholder Anatoly Karpov nears its end, the hotheaded maverick from the southern city of Baku is threatening to take the crown -- a prospect that sends jitters through the staid world of chess.

Ever since chess officials abruptly canceled the last Karpov-Kasparov championship match in February, the challenger has been in a public feud with the Soviet and international chess establishment.

Displaying unusual brazenness for a Soviet public figure, the young Kasparov has flailed at some of chess' sacred cows. In interviews abroad, he has disputed Karpov's right to the title, accused the head of the International Chess Federation of "doing anything for money" and charged Soviet chess officials with doing everything to protect Karpov.

"My relations with the U.S.S.R. Chess Federation couldn't be worse," Kasparov said in a typical and, in Soviet terms, astonishing statement during an interview with a Yugoslav journalist earlier this year.

All this has heightened the drama on the stage of the Tchaikovsky Concert Hall, where the two men have been playing since Sept. 3.

The contest has taken on political overtones -- certainly within the chess world, where top-ranking chess officials are closely aligned with Karpov, who has held the title for 10 years.

In the 34-year-old Karpov, the chess establishment had an establishment champion, a Russian by nationality and a team player by temperament. The same would not be true for Kasparov, who is half-Armenian, half-Jewish and from the predominantly Moslem republic of Azerbaijan.

In and of themselves, Kasparov's origins are not unusual for Soviet chess. Many Soviet grandmasters are Jewish, and one of the most famous world champions from this country was Armenian.

But combined with his dark good looks, his dramatic flair and his attacking style of play, Kasparov's background has added an exotic touch to the usually gray cast of characters in Soviet chess.

His mother, Klara, present at every match, is stopped in the lobby of the concert hall for autographs. His girlfriend, a well-known actress, also goes to the games.

For all his outspokenness, however, it would be wrong to see Kasparov as a political outsider in the Soviet Union. Like Karpov, he is a member of the Communist Party, and while his base of support is far from Moscow, he is known to have the backing of Politburo member Gaidar Aliyev, also from Baku.

And while the chess establishment may see him as an enfant terrible, chess fans here seem to love him -- because he is the underdog who was unfairly treated, because he has spirit and because he plays amazing, aggressive chess, which to some extent reminds them of another chess idol here -- Bobby Fischer, the eccentric American who forfeited the title to Karpov in 1975.

Chess in the Soviet Union is like chess nowhere else. The Soviet Chess Federation has 5 million members, and 40 million more people play -- in clubs, in parks, in schools. The national passion has given the Soviet Union world dominance in the sport: the men's title has been in Soviet hands for all but six of the past 58 years.

Given the personalities and the rivalry, this match has captivated the chess public here. Families stop talking when results come on the evening news, and players endlessly debate the moves. In recent games, fans have roared and clapped as Kasparov revealed a coup de grace. The managers of the match, unused to such lapses, have since put up signs saying applause is forbidden.

Within the hall, the antagonism between the two players has spilled down through the ranks of chess grandmasters, journalists and fans. People talk about possible changes in the chess world if Kasparov wins, although it is difficult to judge how much power a new champion can wield. Jobs and such privileges as permission to travel abroad for tournaments could be at stake.

According to Kasparov supporters, his followers in the ranks of Soviet grandmasters and international masters recently have not been getting travel permission.

A key culprit in the minds of Kasparov's followers is Florencio Campomanes, president of the International Chess Federation, who decided last February to end the match just when Kasparov was winning games.

Campomanes is closely tied to Karpov, to the point where his nickname here has become "Karpovmanes." Not surprisingly, other ranking officials are also loyal to the champion, including the 20 trainers said to be helping Karpov, compared with five helping Kasparov.

Karpov's long tenure as champion has made him a fixture in the chess world, albeit a bland one. Slightly built, with a strange, high-pitched voice, Karpov is not a champion fans can easily warm to. In the last match, he lost 24 pounds and looked to be on the edge of exhaustion.

This time, although the match is shorter, with a 24-game limit, Karpov again seems worn down by the battle of nerves. "I think he is tired spiritually, his morale is low," said Maya Chibordanidze, 24, the women's world champion. "He has been losing and he can't bear it."

What he lacks in charisma, Karpov makes up in chess. His game is considered awesome, highly technical and often flawless. He rarely loses -- this is the first time he has trailed in a title defense. Most importantly for Soviet chess, he has won when it counted most, namely against Viktor Korchnoi, a Soviet defector, in a celebrated 1978 match.

For that victory and for his quiet, dignified representation of Soviet chess, Karpov has been given a place in the ranks of the Soviet political establishment and awarded the Order of Lenin.

Kasparov's style is completely different. The contrast was most evident in two recent games when Kasparov played out a move normally sealed for the next day's play -- a gesture of defiance that delighted the audience.

Kasparov cuts a dashing figure and he knows it. When he finishes a move, he strides toward the back of the concert stage and practically flings open the heavy curtains, heading for a backstage retreat. Or he paces up and down the stage, hands behind his back, the portrait of the intense young genius.

Kasparov gets a warm response in the hall, but there are still many Soviet chess fans loyal to Karpov who resent the challenger's brazenness. A hint of Russian chauvinism also can be heard among Karpov fans, and there is some sympathy for a champion being crushed by the energy, daring and scorn of a younger challenger.

Kasparov was born of an Armenian mother and a Jewish father (his name is a Russianized version of his mother's maiden name, Kaparyan) and started to play chess as a child. According to one story, he was 6 when he advised his parents how to solve a chess problem posed in the local newspaper.

His career was meteoric. When he was 11, he played Karpov, already world champion, in a simultaneous game with other youngsters. Karpov is said in one account in a Soviet newspaper to have noted that Kasparov had "prospects." By 17, Kasparov was an international master and at 18, Soviet champion.

Kasparov had been known for his impetuosity before the start of last year's championship match, which he began with great bravado only to fall behind, 5 to 0, in the early games. But it was the disastrous end of that match that put him in the spotlight.

After five grueling months of draws, the match was abruptly called off by Campomanes just after Kasparov won two games, putting the score at 5 to 3. Campomanes said the decision was made for the sake of both players, but chess experts here and abroad saw it as a move to protect a physically exhausted Karpov from humiliating defeat.

At a press conference called to announce the decision, Kasparov went public with his outrage -- a rare event here -- and demanded that Campomanes explain the "spectacle."

Yet some chess experts say that in the end, Kasparov may have benefited the most from the duel last winter. "The first match was a fantastic school for Kasparov. Karpov gave Kasparov fantastic training," said Soviet grandmaster Eduard Gufeld. "In this match, Kasparov is playing twice as strongly."

The grandmasters here all expect to see more of the Karpov-Kasparov rivalry, noting that a rematch is likely within the next six months, regardless of who wins.

"Usually in chess history, there was always one genius," Gufeld said. "In this case we have two geniuses, which we have never seen before."