Bill Walsh has been a head coach in the National Football League for only three years and his teams have had just one winning season, hardly the credentials expected from a man considered a football genius by many of his peers.

Yet Walsh, the mastermind behind the rebirth of the San Francisco 49ers, has emerged as a dominant figure in the playoffs.

His 49ers, who won just two games in 1979, compiled the league's best record this season and now are only one victory from the Super Bowl. He also is linked closely to the quarterbacks of both San Diego and Cincinnati, the AFC finalists.

Cincinnati's Ken Anderson, who led the NFL in passing this season, readily admits that Walsh, the Bengals' offensive coordinator in the early 1970s, was responsible for making him a polished pro.

And San Diego's Dan Fouts, one of the most prolific passers in league history, says that Walsh, as the Chargers' offensive coordinator in 1976, salvaged his faltering career and restored his shattered confidence.

If the 49ers beat the Cowboys Sunday, Walsh will match wits in the Super Bowl with Fouts or Anderson. And his appearance in Detroit just might make up for the frustration of waiting 22 years for an owner to decide he was talented enough to coach an NFL team.

"I would say everything that has happened to me this year serves as an inspiration for all those longtime assistant coaches who think their chance will never, never come," said Walsh, the league's coach of the year.

Walsh is a thin, scholarly man who looks and acts like a college professor. His classroom is the practice field, his students are the players precisely schooled in the intricacies of football.

Walsh almost decided in 1966 to drop out of coaching and obtain a master's degree in business at Stanford. A one-time boxer, Walsh says he might be playing lead guitar for Willie Nelson if he hadn't decided to be a football coach. Or working as an executive for an electronics company.

He is not the prototype of a pro coach. He doesn't grit his teeth, chew tobacco, spit out bromides or inspire his players with fiery pregame speeches. Nor does he work the killing hours that have become the NFL norm.

"He has a very quick, agile mind," said Mike Brown, Cincinnati's assistant general manager and a longtime Walsh friend and admirer. "If you had to use one word: bright. And he's a good guy, a lot of fun to be around. He's got that type of active mind that's always working."

Yet fans sees little of Walsh's light side. He rarely laughs or jokes in public. Football is a serious topic that should be discussed thoroughly and openly, in the same manner one might explain macroeconomic theories.

He learned from the masters: Al Davis at Oakland (teaching the theories of Sid Gillman) and Paul Brown at Cincinnati, where he developed from an obscure assistant to the man responsible for the Bengals' highly productive passing offense of the early 1970s. Yet when Paul Brown retired in 1975, he chose line coach Bill Johnson, not Walsh, as his successor. Hurt by the decision, Walsh left for San Diego, then become Stanford's head coach for two seasons before being hired in 1979 as the 49ers coach-general manager.

With the 49ers, he has made 28 trades and reworked a roster that now has only 12 players remaining from the pre-Walsh era. "He's grown into his present job," Mike Brown said. "He was a technician when he left us. Now he can handle all aspects of his position. He's no overnight success. He's earned it."

Probably no one in football understands the passing game better or has been more successful teaching it. His two Stanford quarterbacks, Guy Benjamin and Steve Dils, both were NCAA passing leaders. Once they left him, neither flourished.

Anderson won two NFL passing titles when Walsh was in Cincinnati. San Francisco's Steve DeBerg set league records for attempts and completions in 1979, a year after he was the lowest rated quarterback in the league. Joe Montana, a third-round 1979 choice, was the NFC's No. 1 passer this year, his first full season as a starter, even though the 49er running game is one of the league's weakest.

"He doesn't coach offense like anyone else," said Jerry Glanville, Atlanta's defensive coordinator, who insists he has studied Walsh's offense "more than any man alive."

Granville says Walsh's teams are "intelligent. It's tough to force them into mistakes, and you can't get much of a pass rush on them because they throw a lot of quick, short timing patterns. I don't know how he practices everything he has. When we prepare for them, I need a wagon to carry all my play charts."

When teams were still emphasizing the run, Walsh was one of the first to control the ball using the pass. Purists say he nickels and dimes defenses to frustration.

He admits his quarterbacks will look away from the primary receivers faster than most teams. But his short-pass philosophy--"we'll settle for second and six any time instead of having a 15-yard incompletion or an interception"--can both camouflage a lack of talent and take pressure off his defense by producing time-consuming drives. Anderson recalls throwing for 300 yards one game "without completing a pass over five yards."

In Cincinnati, Walsh is remembered for doodling plays on a napkin and turning them into game winners on Sunday. Sam Wyche, the former Redskin and now the 49er quarterback coach, estimates that as many as 20 percent of the team's passing plays every game "are brand new, never-before-used plays that we put in the week before. Fifty percent of what we will use in a game won't appear in the films opponents use to study us. That's how much we switch during a season."

"I don't have a label for what we do," Walsh said. "It just follows what Sid Gillman was teaching years ago. We don't do things in grandiose fashion. We aren't greedy. We don't need to get huge chunks of yardage at once. We take calculated risks, we don't get carried away and use a Star Wars, out-of-sight approach. We don't say, 'Here is our system. No matter what you do, we will use it and beat you.'

"We study defenses, then attack them with what we think will work best that week. It means remaining flexible and adaptable."

Joe Gibbs, the Redskins' coach, admires Walsh so much he studies 49er films in the offseason, particularly the innovative pass patterns. Walsh's quarterbacks are disciplined and consistent.

"If he tells you to take a five-step drop and you take three, you do it over again even if it was completed," said Montana, who rarely forces the ball into coverage or depends on reading defenses as much as other NFL quarterbacks. "In his mind, plays work because you execute them a certain way. Without him, I'd be way behind where I am now."

Atlanta's Glanville is one of the few coaches who has been successful defending against Walsh. He says he usually receives calls from 49er opponents "who are confused and want help. I was expecting a call last week from the Giants (prior to their NFC playoff game with the 49ers). They never called."

The Giants lost. Glanville still is waiting for a phone call from Dallas.