By the time John Riggins had finished his 43-yard run against Miami last January, he had done more than turn the Redskins into Super Bowl champions. He also had helped transform the one-back offense from a novelty into what could be the National Football League's dominant offense in coming years.

NFL teams are copycats. When one club has success with something (3-4 defenses, nickel alignments, shotgun formations), others are sure to try it.

Now that the Redskins are NFL champions, thanks in large part to the one-back setup, that offense is catching on. Its advocates see it as much more than just the latest fad.

"All the wise ones are going to the one-back," said Sid Gillman, one of the most respected offensive thinkers in football. "Why? Because you have to be able to throw the ball and you can't throw the ball as well with two backs as you can with one.

"I'll guess that as many as eight teams in the NFL wil be in a one-back backfield most of the time this season. Maybe more."

Although the majority of teams will keep the two-back pro set as their basic formation (it's difficult to abandon years of accepted thinking without hesitation), perhaps all but a handful will employ the one-back some of the time. One NFL scout who reviewed preseason game films involving 16 teams said each one was experimenting with a one-back set.

Some, including the Redskins, Atlanta, Cleveland and San Diego, will run the one-back almost exclusively. Others, like Pittsburgh and Dallas (which calls the alignment "Jayhawk") and possibly New England, likely will use it at least half the time; Minnesota will use it slightly more than that. But if another one-back team wins a Super Bowl, watch the stampede to any clinic that is conducted by Joe Gibbs or Don Coryell.

"It has proven to be successful, which is a good enough reason to use anything," said Dan Henning, Atlanta's new head coach, who learned about the one-back as Gibbs' chief assistant in Washington. "I've seen how the offense can be adapted to different personnel. I've seen how it can be used against all types of defenses. I've seen how you can have the best of both worlds with it: you can run the ball effectively, like the Redskins and Riggins did, and you can pass the ball with great consistency.

"Washington showed the offense's potential. You can control the game with short passes, you can go long any time you want, and if it's executed right, you can be effective without making turnovers. And you don't need a John Riggins-type back to run. Joe Washington had great success with it two years ago."

Says Larrye Weaver, Cleveland's new offensive coordinator, who has installed the one-back offense during training camp: "The evolution of the one-back is still to come. It is still in the infancy stage. When more people can involved in developing it, there is no end to where it can go. I think it is more than a current vogue; I think it is here to stay."

Says Tom Moore, Chuck Noll's first offensive coordinator at Pittsburgh: "In the game of football, you try to be a year ahead of time, not a year behind. We've done a lot of research on the one-back in the offseason and we've made adjustments in our system to incorporate it.

"We think this is the way you should be going in football right now."

Certainly, longtime NFL observers can remember the Detroit Lions using a one-back offense 25 years ago. But although it's true that the use of a lone running back dates to at least the 1950s, in those days teams weren't combining a one-back look with a man in motion. And that is the key change.

The modern version of the one-back formation might have taken shape when Gibbs was an assistant coach in San Diego. While devising a game plan for Denver, the Charger staff was considering how to use better a big, quick tight end named Kellen Winslow. What they came up with involved using two tight ends and one running back, with Winslow employed as a motion man.

Now, teams who don't have someone like Winslow have found that, by using a combination of motion, one running back and four receivers (either an extra tight end or an extra wide receiver), they can reach the same rarified offensive atmosphere that the Chargers once occupied alone.

"With the rules the way they are today--allowing receivers so much more freedom in the secondary--it's to your benefit to get four receivers instead of three out on patterns as fast as possible," Gillman said. "What better way to do it than to take a back and make him a receiver, so he is set closer to the line?"

But without the motion, the one-back set would not be as successful, regardless of how many receivers were used.

"By putting a guy in motion," said Weaver, who is the first offensive coordinator employed by Cleveland Coach Sam Rutigliano, "you create coverage and support problems for the defense.

"You use the movement to disguise your formations. When you set up, the defense has to decide where the motion man is, what position he is playing initially, what position he will wind up playing by the time his motion ends and who is going to cover him," Weaver continued. "It upsets their keys; they aren't sure what formation you are using.

"They have to make all their decisions in a matter of seconds. That's why you see an awful lot of defensive players' heads moving back and forth very quickly out there. They are trying to figure out what is going on. If you can create doubt, then you have an edge on the defense."

When teams line up in a standard alignment with two backs, one tight end and two receivers, the strong safety covers the tight end and the free safety can either double-team a receiver or help out against the run. But when a team uses just one back and four receivers and then puts one of those receivers in motion, the free safety no longer is free: he must assume primary coverage responsibility on the extra receiver. Suddenly, defenses against both the pass and the run are weakened and there is more one-on-one coverage, which is always a plus for the offense.

"With four receivers, you spread out the defense and widen the field," said Moore, who employs a flanked-out halfback or a third wide receiver as a motion man. "But you don't throw off your own run continuity. You still can run equally as well to either side."

Gibbs says he was attracted in part to the one-back, two-tight end formation because the Chargers had to play so many teams that used a 3-4 defense (three linemen, four linebackers).

"If you have a tight end at either end of the offensive line, you've got a guy weighing 240 pounds blocking on an outside linebacker on every play," said Gibbs, whose Redskins have won 20 of their last 24 games with the one-back setup.

"With only one tight end and two backs, if you run to the weak side (away from the tight end) with John Riggins, you have a little guy like Joe Washington trying to block a linebacker.

"I'd rather have a tight end blocking at the corner instead of a halfback."

There is an added benefit. Players getting their first exposure to the alignment's intricacies come away enthusiastic. "We are keeping things pretty subdued in training camp," said Atlanta quarterback Steve Bartkowski. "But once the season opens, it's going to be a no-holds-barred story."

"The players all seem to love it," Weaver said. "It keeps practices interesting because they never know what to expect from day to day.

"There are so many things you can do that it's always a challenge.

"It's exciting to me, too. The biggest problem I have is to know when to shut down. You want to go in leaps and bounds, but you have to hold back or the players can't keep up. The players see me coming to practice and they all say, 'Here's comes the mad scientist out of his lab.' That's how advanced the one-back thinking is."