he San Antonio Spurs held a contest last year to name their dance troupe and got 3,162 entries, everything from Ice Pets--after Iceman George Gervin--to the Alamo-ettes, as in the Battle of. They chose Quicksilver, and here's why.

"My group is not cute," Lisa Hawes, the troupe's choreographer, told one of the local papers, "and I wanted something sultry, sophisticated and classy."

Sultry, sophisticated and classy are definitely not indicative of what you will find inside the HemisFair Arena Friday night when the Spurs meet the Los Angeles Lakers, their best-of-seven NBA Western Conference final series tied at 1 (WDVM-TV-9, 11:30, tape delay).

Instead, you may find adults in pajamas and robes whooping it up over the top of the Lakers' dressing room, a coyote leading cheers, a Mexican beer-drinking song at the end of the third quarter, strains of the "Twilight Zone" theme if the refs make a bad call, lots of country-western music, and cheers that will be deleted for national TV.

All of that will be a reminder that the conference finals have shifted from the glamor and glitter of Los Angeles to the truly weird setting of San Antonio. Once high school football was the law of the land in San Antonio, but in 10 years, the Spurs have changed all that. Now this is a basketball-mad city.

And we are talking weird. The pajama-clad folks, who may also come equipped with shaving cream and pie plates and other props, are known as the Baseline Bums, a semiofficial cheering section about 80 strong that got its start when its members were bleacher bums at the baseball games here many years ago. But when the Spurs moved here from Dallas a decade ago, the Bums switched their allegiance and have become an institution almost as important as the team itself.

"Between the dementia of the fans and the schizophrenia of the team, the Spurs already lead the NBA in psychic disorders," wrote Peter Applebome of Texas Monthly Magazine last December.

The schizophrenia is a reference to the Spurs' annual collapse in the playoffs, something fans here are praying will not happen this year. The dementia is apparent from one look at the slightly intoxicated cheering section.

When Karem Abdul-Jabbar first started wearing protective glasses, the Bums all showed up to welcome him wearing goggles. When Gervin accidentally slipped the Phoenix Suns' Alvin Adams an elbow a few years ago, the Bums showed up for the next Suns game wearing adhesive tape across their noses.

No one is sacred. At a party for new Coach Stan Albeck, the Bums showed up wearing wigs to match his silverly perm.

The Spurs management puts the Bums just over the entrance to the visiting team's dressing room and, once, Calvin Murphy tried to scale the wall to get at them. But Spurs officials insist many visiting players and referees enjoy the Bums. "Dr. J thinks they're great," says one club official.

The management says the fans have cleaned up their act from the old ABA days, In those days, someone dropped guacamole on the head of Larry Brown, former Denver Nuggets coach, after he had said the only thing good about San Antonio was its guacamole.

But there is still enough beer consumed to make the Bums slightly dangerous in a dimly lit pavilion. Ronnie Jackson figures he is one of the most temperate of the clan. "I drink about two or 2 1/2 six packs a game," he says.

Phill Rice has been a Bum for seven years. He hails from Indiana and so he knows of truly weird basketball fans. He and his wife took over the Bums' memberships from their daughter and son-in-law. They are known within the Bums as Papaw and Mamaw, and Phill's favorite cheer is: "Two bits, four bits, six bits, a peso. All for the Spurs, stand up and say so."

The Bums don't want to give the wrong impressions. They are a well-organized club, with by-laws and annual dues of $15 and preselection interviews.

Papaw puts the Bums into proper perspective. "The Baseline Bums are not any worse than sitting anywhere else," he says. "You hear foul language and get beer spilled on you anywhere."

He is correct. The Bums are only part of the show at the Spurs games. There are others to be wary of. Like the elderly woman who sits beneath one of the baskets, waving her arms to jinx the opposing team when someone is shooting free throws. Or the loyal fan who rarely misses a home game, despite the 220-mile round trip he makes from west of Austin. He wears boots that look like basketball shoes and makes it his duty to bait the referees.

Friday's game won't start until 9 p.m. local time, but the Spurs have scheduled a pep rally in the arena at 6:45. Spurs publicity director Wayne Witt said one reason was to get the fans "off the streets" early. "We have tremendous traffic problems," he said.

But Albeck understands the consequences of opening the concession stands several hours before the game. "By 8:30," he said, "everybody will be drunk."