Perhaps it's best to begin on the day Juan Morgado's cozy chess bookshop suddenly got considerably smaller. It was a Wednesday, around 6 p.m., when a surprisingly portly Bobby Fischer walked in, accompanied by his very large ego and a laconic Filipino grandmaster.

A Bolivian chess aficionado browsing the shelves in the narrow room recovered from shock and moved to get an autograph from Fischer, whose infrequent sightings still set some people, especially chess people, aflutter. The Bolivian's fatal error was opening the encounter by innocently offering up a copy of Tiempo de Ajedrez, or Chess Times, which Fischer declined to sign because he said the publication's "informants are my enemies."

That, as it turns out, set the tone for an odd visit to Argentina, which ended sometime over the past few weeks as rudely, as suddenly and as mysteriously as it began in late June. Since then, Argentina's large chess community has obsessively analyzed the tidbits that Fischer tends to leave behind wherever he goes these days, the off-the-board moves that add to his already enormous reputation as an eccentric.

"Very perturbed," is how Morgado, a grandmaster himself, described the chess legend. On a bulletin board behind the door, Morgado displays the only evidence of Fischer's two visits to the shop: signed receipts for $249 worth of chess books, for which he paid in cash from a thick wad he kept in a leather pouch anchored to his waist. "He spent most of his time trying to hide," Morgado said. "Apparently he didn't know what to do with his free time."

"He eats like a machine. That's why he is so fat," offered Pablo Ricardi, a two-time Argentine chess champion who dined with the once-svelte Fischer at a Japanese restaurant. As in all encounters here, the dinner chatter that night centered on Fischer's claim that most chess championships are fixed -- his obsession being the Karpov-Kasparov 1985 title match. "He is a megalomaniac," said Ricardi. "I told him it would be strange to fix all the matches. But he insisted they were."

To those who have lost the libretto, here's a summary. A grandmaster at the age of 15 and world chess champion from 1972 to 1975, the Brooklyn-born Fischer dropped out of the chess scene after his exacting demands for the 1975 world championship final were rejected by the International Chess Federation. Over the next 17 years, Fischer sightings were rare and, when they occurred, bizarre.

He was arrested, by mistake, in Pasadena, Calif., on suspicion of bank robbery. That turned him from a hermit into a pamphleteer, and his "I Was Tortured in the Pasadena Jail House" is now an unlikely chess classic. In 1992 he was lured back into chess by a Romanian girl's charms and/or a Yugoslav financier's money and agreed to a rematch with his 1972 foe, Boris Spassky. The setting was a theater of war, Yugoslavia, and Fischer came away with $3.5 million in prize money and an indictment from the U.S. government, which accused him of violating a U.N. embargo.

The Spassky rematch apparently convinced Fischer that chess needed some changes, which is what he has been working on ever since and what brought him here. Buenos Aires, it turns out, was chosen as the site of the world premiere of Fischerandom Chess, the grandmaster's effort to save chess from the computer-mad players who have turned it into a bore.

(Did you ever wonder why so many players now wear glasses?, Fischer asked Ricardi. It's because they spend all their time in front of computers, Fischer explained, worrying over openings and, presumably, closing their eyes to the harm they are doing to their vision.)

The solution Fischer proposes is a random distribution of the pieces on the first row of the chess board. Accomplished with an electronic "shuffler," Fischerandom creates 960 possible variations of starting positions and eliminates the familiarity that has bred tedium. To those who dismiss Fischerandom as needless tampering, Fischer supporters point out that his other invention, a chess clock, was greeted with similar derision but is now hailed as a revolutionary leap.

"Chess is now a game of memory, and that is totally boring," said Miguel Quinteros, an Argentine grandmaster who has known Fischer for 25 years and is described by others as one of his few close friends. "Fischerandom is the chess of the future, and it is going to be very successful. I can assure you that if it is not going to happen sooner, it will happen later."

For now, it looks like later. Fischer never premiered his new version and instead left for Budapest in a huff, angered because one or more sponsors never came through. Ricardi, who was to play the inaugural match against Fischer's constant companion, Filipino grandmaster Eugene Torre, now dismisses the event as "economic fraud."

Fischer still collected his $100,000 fee, although it is unclear who footed the bill or what was given in return. Quinteros, who orchestrated the event and confirmed the payment but would not discuss the payee, said he is still hoping to lure the legend back next month for the debut of Fischerandom. But Ricardi and others doubt that will happen. Worse still for a man with few friends, chess players here say Fischer was so miffed at Quinteros's bungled event that the two are not speaking.

Which leaves Argentina's chess community -- an international contender, particularly in its heyday between 1950 and 1970 -- no choice but to mull over the non-chess side of Fischer. In Morgado's chess bulletin, for example, Fischer's Buenos Aires moves are described in detail, including transcripts.

His fulminations against the new edition of one of his books include the charge that the publishers purposefully changed the color of the front and back, from orange and white to blue and black, "to make me appear . . . dark and gloomy." And he railed against Mickey Kantor, who led the Clinton administration's condemnation of his match in Yugoslavia. "The only place Kantor is happy," Fischer said, "is in the synagogue."

Quinteros, who was with Fischer when he defeated Spassky in '72 and again in '92, downplayed these incidents and said Fischer is neither as strange nor as anti-American as some have portrayed him. "He likes his country," Quinteros said. "He may not appreciate some of the people who are running it, but there is no doubt that he likes his country."

Fischer's first visit to Argentina was in 1971, when he defeated Tigran Petrosian in the set-up to the world championship. Adulating Argentines gave Fischer a hero's send-off after his victory, and ever since there has been an affinity between the capricious chess king and a legion of followers here.

A lot has happened since. The boyish Fischer who left in 1971 wore dark suits and thin ties, combed his hair and smiled a lot. And then, a quarter of a century later, he came back a burly and angry man with a salt-and-pepper beard, a baseball cap and a head full of conspiracy theories.

But despite everything -- and even chess people who were put off by Fischer's arrogance this time around agree on this -- the man remains oddly magnetic, and not only because many believe him to be the best chess player ever. "It's like talking to a superman. I felt like I was in the presence of a hero. You don't know what his limits are," said Armando Hiebra, a chess impresario here. "Everything is surrounded by -- what can I call it? -- a certain kind of magic." CAPTION: Awaiting his next move: Former world chess champion Bobby Fischer, at 53, has been keeping them guessing in Argentina.