When Joe Gibbs was hired after the 1980 season to coach the Washington Redskins, it was presumed that if and when he took the team to the NFL playoffs it would be because of his version of Air Coryell and not because of something called the Riggo drill.

Gibbs was tapped by the team's owner, Jack Kent Cooke, primarily because of his highly developed offensive tactics. Gibbs seemed to be the man to reintroduce excitement and the forward pass to a Washington team that, for too long, had been restricted by dull play-calling and unimaginative game plans.

If the Redskins were going to win under Gibbs, they surely were going to do it just as Don Coryell's San Diego Chargers do: lightning air strikes, big plays and lots of points.

Gibbs' second Washington team, 5-1 and tied for first place with Dallas in the National Football Conference, has almost certainly gained a spot in the playoffs -- the first time for a Redskins team in six years. But instead of a thrill-a-play system, the Redskins thrive on, of all things, a possession offense dominated by fullback John Riggins (the Riggo drill is an end-of-practice drill featuring Riggins).

Gibbs tried to be fashionably fancy his first season. And, possibly, if the Redskins hadn't lost their first five games, they'd still be throwing 40 passes a game. But it took those five consecutive winless weeks to show Gibbs that his highly sophisticated playbook wouldn't work for his blue-collar players.

"That's what we are, a bunch of blue-collar workers who don't mind slugging it out every week," said Joe Bugel, the Redskins' offensive line coach.

Nevertheless, Gibbs has proven to be innovative, especially in the development of his one-back offense. The Redskins still try for the big play and run multiple formations and patterns. But instead of a constant dose of finesse, Washington now relies as much on power and agressiveness, both on offense and defense.

"This is not a conservative team," said Gil Brandt, the Dallas Cowboys' personnel whiz. "They have lots of formations, lots of motion. But what they have done is build a high-percentage offense, not a high-risk offense."

That's what is so fascinating about Washington's climb from the bottom of the NFL heap. There are no mysteries surrounding the team's turnaround.

Instead, there are obvious technical reasons for the change.

The Redskins have accomplished perhaps the most difficult feat in pro sports. They have undergone major changes in their roster and still won. Of the current 49-man squad, only 19 players (10 of 22 starters) were on Jack Pardee's 1980 team. Pardee's roster contained four drafted players; this year's has 17. Pardee's roster had 13 players 30 or older; this one has nine (five are starters).

"They probably could have kept some more older players, but they decided to bite the bullet right away and make the change," Brandt said. "It took guts, but, as a result, they are only going to get better and better."

If Joe Gibbs ultimately fulfills the promise he has shown in his first two years with Washington, he will have no particular difficulty identifying the turning point in his career. At 0-5 last season, he could have stuck stubbornly with his training-camp playbook. He could have refused to back off his pass-first approach. What he did took courage; he conceded that many of his offensive ideas needed to be altered, that he had been coaching incorrectly.

"We were a two-back offense trying to do a lot of things that weren't advantageous to our players," Bugel said. "We reevaluated our personnel. We stopped overstretching our personnel, asking them to do things they couldn't. We plugged them in better."

At 0-5, the Redskins had committed 21 turnovers. They had been outscored by 72 points. They had been penalized 41 times, most in the NFL. They were making so many mistakes that their defense, which was not strong, was on the field constantly. They were trying to be so aggressive offensively that they were forcing things to happen. Quarterback Joe Theismann was erratic. Gibbs wasn't sure about Mark Moseley, who had missed some early game field goals.

"We were self-destructing," Gibbs said.

Since those dark days, the Redskins have, over the past two seasons, won 13 of 17 games, including the four that began the current strike-interrupted season. The four most significant reasons for the turnaround are:

* The one-back offense. Gibbs helped install the one-back offense at San Diego, but, when he came here, he decided he wanted both John Riggins and Joe Washington in the same backfield. Yet he switched to the one-back approach, which appears geared for passing, to improve his team's running game.

"The one-back is a heck of an innovation," said George Young, the New York Giants general manager. "Instead of having a small halfback trying to block on sweeps, you now have a tight end on either side doing the blocking. And with all that motion, it creates mismatches. They are always trying to get a speed guy on a slow guy or a little guy on a big guy.

"And with four receivers on every play, it messes up your run support. It takes a guy who could help on the run and makes him play pass defense down the field. So they have less guys to block on the corners when they run."

Gibbs: "With the one-back, we began running better. We got better ball control and, with tight ends on both sides, we had better pass protection, which gave Joe Theismann more time to throw. We stopped losing the ball."

* Better use of personnel. Now that the staff has a clearer idea of player strengths and weaknesses, the Redskins have become a role team. For example, early last season, tight end Don Warren was being asked to run deep patterns down the middle despite an obvious lack of speed. Now he is a short-pass receiver and blocker, tasks he does well.

The young offensive line, which has four two-year starters, only concentrates on about 10 running plays. "We also began overcompensating on protection," Bugel said. "If there is a great pass rusher on the other team, we make sure there is a back or a tight end there all the time to help block him."

Art Monk was the only dependable receiver last September. Now Charlie Brown has been added on the other side, and Virgil Seay has developed into a capable backup. Riggins appeared out of shape and dragging last fall; now, helped by weightlifting, he gets better as a game progresses.

"I couldn't say the Redskins have one personality," Brandt said. "I'd say, 'What down and distance is it?' They can be a passing team, a power team, almost anything, depending on the personnel they send in. It's a different offense when Washington is the running back instead of Riggins."

* Joe Theismann. "He's their pied piper," Young said. "When I look at the Redskins, I see Riggins, Moseley and Theismann. He's become a heck of a quarterback. He's playing with confidence now and it shows."

Early last season, Theismann was convinced he had to be the whole show. Ironically, he became their most pivotal part after his role was reduced. As soon as the one-back offense took hold and the Redskins began running better, his passing didn't have to carry the offense. He became comfortable in an offense tailored to utilize his roll-out talents. And Gibbs' confidence in Theismann increased.

Gibbs: "As he goes, we go, it's that simple. He's been so consistent since early last year. He's only been off one game this year, against Dallas. We surrounded him with lots of different people (seven new starters) and things weren't smooth. Now he knows who is going to play and when."

* Defensive aggressiveness. Injuries and inexperience destroyed defensive continuity last year, even after the team's record improved. This season, the Redskins are compensating for a still-lingering quickness problem with more diversified formations, including occasional three-man lines, and with more forceful tackling. Their pass rush has improved, as has their ability to stop the run.

"With more looks, we are harder to prepare for," Larry Peccatiello, linebacker coach, said. "Remember, in a year we changed both starting ends and both cornerbacks . . .

"We have a lot of role players, are getting a lot of people involved, getting them experience. Look at Darryl Grant. He did a fine job starting for Perry Brooks last week. If he hadn't gotten in earlier (as a 3-4 nose guard), it might have been different." Next: Personalities graphics /photo: AP Coach Joe Gibbs and quarterback Joe Theismann have good rapport.