LAS VEGAS -- The old term "bookie joint" would hardly apply to most of the establishments in this city that take wagers on sports and horse races. Big-scale bookmaking is now conducted mostly at the big hotels, such as Caesar's Palace and the Mirage, in glitzy rooms with large-screen televisions and snazzy electronic boards posting odds and results. The operations are supervised by layer after layer of corporate executives.

In such an environment, Leroy's Race and Sports Book looks like a throwback to another era. Race entries are listed on big cardboard sheets and results are posted by hand. The unadorned room is filled with smoke and littered with the patrons' beer bottles. There are few tourists in the crowd; this is a collection of scufflers, wise guys and hard-core gamblers. When a camera crew was preparing to film at Leroy's -- to document a little local color -- owner Vic Salerno cautioned them to be judicious. "Some of our customers might be on the lam," he said.

And unlike the big hotels, there are no executives in suits at Leroy's. Instead, there is Salerno, sitting in an inelegant back room, drinking tequila, grumbling and cursing when a football game goes against him.

This is a bookie joint. Yet, for all its apparent crudeness, Salerno runs one of the most sophisticated gambling operations in Las Vegas. He brought computerization to bookmaking, and he revolutionized the business, making himself a wealthy man in the process. "He's had an immense impact," said oddsmaker Roxy Roxborough. "He's made the whole business faster and more efficient."

This was hardly a life that Salerno could have envisioned while he was practicing dentistry in Marina del Rey, Calif. He had an office with an ocean view and an upscale clientele that enabled him to earn $200,000 a year, some of which went to finance his hobby: gambling. On Fridays, Salerno might spend the afternoon at Hollywood Park, followed by an evening at Los Alamitos for the quarter-horse card, then catch a late-night flight to Las Vegas.

When he married in 1975, Salerno not only found an understanding wife, but a father-in-law who shared his passion for action. Leroy Merillat had been a successful businessman who went to the track incessantly, but his ultimate dream as a gambler was to be a bookmaker. In 1978 he got a one-year license and opened Leroy's in Las Vegas. He was an aggressive promoter and he generated a remarkable amount of business, but he also demonstrated what a tough game this is: He lost $1 million. When Merillat encountered complications in getting his license renewed, Salerno took over.

The fledging bookmaker learned that every game has its special angles, and that Las Vegas is filled with wise guys trying to exploit every tiny edge. Booking their action isn't as soft a touch as, say, booking bets for dentists in Los Angeles would have been. On his first Super Bowl, he lost $64,000. As he took these risks, he developed a contempt for the big betting establishments that seemed loath to take any themselves.

"I don't want to badmouth the other places," he said, "but they're chicken." The big hotels would often impose cautious limits on sports wagers, and would regularly turn down big bets on horse races, despite their formidable assets and the fact that their casino operation puts them in a can't-lose position. "I've got seven bartop slot machines and they've got 7,000, but they're the ones who get scared so fast," Salerno said.

Even so, as the big hotels began to dominate bookmaking, it became as tough for small independents to survive as it is for a mom-and-pop grocery store to compete with a Safeway on the next corner. "It's a losing proposition," Salerno conceded. "After paying our employees and our expenses, we've had four winning years out of the 13 we've been in business."

Salerno decided that one of the ways to compete was to make his operation more efficient. Even in the mid-1980s, Las Vegas bookmakers were not using computers. They monitored their action on games in the crudest pencil-and-paper fashion. If they were overloaded with bets on one team by thousands of dollars, and needed to adjust the point spread to attract action to the other side, they might not discover their position until the game was well under way. So Salerno hired a Pakistani computer whiz named Javed Buttar to bring his operation into the 20th century.

"With the computer," Salerno said, "we can analyze thousands of bets in 90 seconds. You can look at the screen and see if San Francisco wins, you win $2,123; if San Francisco loses, you lose $1,127."

The software Salerno introduced to Las Vegas was so useful that even traditionalists in the business saw its merits -- and came to Salerno to buy the system. Eventually, Salerno was servicing virtually all of Las Vegas's bookmaking operations, and the computer business was dwarfing his bookmaking business.

And Salerno wasn't finished shaking up the Las Vegas betting industry. He realized -- from his own experiences at Leroy's -- just how tough the economics of small-scale bookmaking had become. Plenty of small casinos wanted sports books to attract customers, but they couldn't afford to pay a competent manager and install the necessary computer equipment. So Salerno proposed to make them outlets for Leroy's. He would either lease space in a casino or go partners with the management, setting up a bookmaking operation hooked by computer to Leroy's. He started with one establishment called Cactus Pete's, in Jackpot, Nev., in fall 1989, and has expanded to 19 outlets with 13 more scheduled -- included big Strip hotels such as the Dunes and the Frontier. Roxborough said, "This is the wave of the future."

Salerno often had sneered at the corporate domination of the gambling business, saying, "Bookmaking is becoming more like Wall Street." Now he has to add, "I guess I'm as much to blame as anybody else."

But there are some concessions that he won't make to his emergence as a major force in the gambling industry. He is not going to wear a suit and tie; he will continue to supervise his business from the same back room, with a bottle of tequila at hand. And Leroy's will not take on even a veneer of glitz or respectability. The flagship of Salerno's far-flung operation will remain a bookie joint.