Sept. 23, 1979, Busch Stadium, the Redskins against the Cardinals. The St. Louis offense crumbles before a Washington defense that utilizes strong safety Ken Houston as a blitzing, penetrating linebacker. Architect of the strategy: Secondary Coach Richie Petitbon.

Oct. 13, 1980, Mile High Stadium, the Redskins against Denver. Tony Peters permanently replaces All-Pro Houston in the starting Washington defense, a move that led to the veteran's bitter retirement. The man who made the tough decision to bench Houston: Richie Petitbon.

Now, Petitbon is the Redskins' defensive coordinator, a position where his ability to devise unique tactics and to make difficult personnel choices could result in a personality change for the Washington defense this season.

Many of the things the Redskins did under Jack Pardee, especially employing players in specialized situations, won't be altered, because Petitbon helped persuade Pardee to adopt the tactics in the first place.

But it is unlikely that the Redskins will approach any game this year with a conservative defensive plan.

Petitbon likes to blitz and stunt and try to force errors with aggressive play, which is likely to result in a more active defense, especially if he can shore up the front four sufficiently to free the linebackers for other duties.

"I think all defensive players love to be aggressive," linebacker Rich Milot said, "and that's what Richie is going to allow us to be. I'm sure we're going to be much more active than we were last year. You're going to see more blitzing, more attempts to make big plays.

"If you don't go after people, you won't force as many turnovers. That's what we're after. We want to cause mistakes. I know I'm looking forward to playing in this system."

The Redskins had just finished a morning practice and Petitbon was walking glumly off the field.

"Bad time to talk," he said. "These guys were horrible out there. Anyone who says this defense is coming around is just whistling in the dark. We've got a long way to go; a long way."

And this from a man whose unit appeared to perform well in an exhibition game last Friday against Kansas City. But where the fans saw strengths, Petitbon saw mistakes and rough edges.

"Too many errors," he said. "We're playing dumb, really dumb. And we aren't coordinated yet. I've seen some improvement, especially in the front four, but I'm sure glad we aren't opening up the season tomorrow. We'd be in trouble."

Although the defensive situation hardly is as gloomy as Petitbon makes it, he is not the type who is deliberately pessimistic. He is one of those rare coaches who assesses situations candidly. If he thinks his players are outmanned or lacking in talent, he'll say so.

Petitbon has moved steadily toward this coordinator's job since becoming a coach in 1974 after an outstanding playing career. He had major input into the Redskin defensive scheme under Pardee, although the head coach served as the ultimate defensive decision-maker. But Petitbon also became frustrated when the Redskins were not as aggressive and reckless as he thought they should be.

Now he has been given the chance by the new head coach, Joe Gibbs, to plot his tactics without restraints.

"I want the defense to be aggressive, too, which is one reason Richie appealed to me as a coordinator," Gibbs said. "We are never going to be a team that sits back and tries to finesse things, no matter what unit it is."

Adjustments have been made to aid Petitbon's desire to attack offenses. Torgy Torgeson was lured from Los Angeles to teach the defensive line a more aggressive, attack-off-the-line approach, rather than the read-and-move scheme of last season. Larry Peccatiello, the Seattle defensive coordinator, was brought in to school the linebackers in technique, something the youngsters at that spot have apparently needed.

But before Petitbon can work on strategy, he has to settle on his personnel. And that's been the stumbling block at this camp, especially with the front four. The Redskins were 27th (out of 28 clubs) against the run last season, with the front four taking much of the blame for the poor record.

The Redskin secondary uses one of the most intricate coverages in the league, and it has the personnel to pull it off: cornerbacks Lemar Parrish and Joe Lavender, both All-Pros; safeties Peters and Mark Murphy, the unit's quarterback; and reserves Jeris White, who probably is as good as Parrish and Lavender, and Mike Nelms, who doubles as a kick returner. Probably only Oakland dares to cover receivers with as many man-to-man tactics as the Redskins employ.

With White available to replace Parrish or Lavender on run situations, which improves the club's ground defense, and with Nelms, an aggressive, talented athlete, pushing for more playing time, especially in short-yardage situations, the secondary appears to be better than ever. Lavender seems to be in the prime of his career, while Murphy has profited by experience and Peters has benefited from being handed the strong saftey spot without worrying about a challenge from Houston.

The situation is less settled at linebacker. The current starting trio of Neal Olkewicz, Monte Coleman and Rich Milot first joined the Redskins two years ago. They've gradually developed into first-rate pros, each filling a central role.

Olkewicz, much improved on pass coverage, is the aggressive, gutty middle linebacker whose hits have been the highlight of training camp. Coleman, the team's most talented defender, is being counted on as the big-play performer and the coaches hope he can frequently duplicate the interception for a touchdown that he registered against Kansas City. Milot gives the club versatility, since he can swing from the outside to the middle.

Behind these three, however, Petitbon and Peccatiello are scrambling. Brad Dusek is making steady progress after back surgery and could be ready for spot duty by the Sept. 6 opener against Dallas. If he is, it will lessen the depth problem. Rookie Larry Kubin has begun his training in the middle and, if his knee holds up, another potential trouble area will be eased.

But until Dusek and Kubin are ready, an injury to a starting linebacker would hurt the defense severely. Peccatiello continues to search for two more reserves from a group that includes Farley Bell, a sixth-round choice last year who walked out of camp; rookies Herb Spencer, from Newberry College, and Mel Kaufmann, from Cal Poly, and veteran Dallas Hickman, once more battling to save his roster spot from the challenge of younger players.

And if Kubin doesn't work out in the middle, either Bill Banks, who almost made the team two years ago, and Dave Graf, a six-year veteran from Cleveland, would have to step in.

"I'm not as concerned about the backup spots as I was," Peccatiello said. "Brad and Larry are coming on faster than we thought and, of course, that helps things. But the younger guys are developing, too.

"Farley is improving almost daily. He needs to work on his endurance but we have his weight down and he feels more comfortable at linebacker now. All of these guys have to show us they can play special teams. That's where your reserve linebackers are really needed. Hickman, for example, has been a leader on the teams for a long time. We take that into consideration."

The front four will benefit from the maturing of the young starting linebackers and from the tight coverages of the secondary. But the major question still has not been answered: Wwill the line be able to improve its pass rush while reducing opponents' success with running plays?

Five weeks into camp, Petitbon and Torgeson have yet to make a change in the front four, despite the addition of newcomers Wilbur Young and Fred Cook. Young showed a better pass rush Friday night but the Redskins would like him to be stronger against the run. And Cook has yet to perform well enough in the coaches' eyes to replace veteran Coy Bacon.

"I'm anxious to get Mat (Mendenhall) back and see what he can do," Petitbon said. "I think he could help us, especially against the run. But I need to know pretty quick." Mendenhall, who, before the trade for Cook, had been projected as a replacement for Bacon on rushing downs, has been sidelined most of the camp with a sore knee. He may resume practice next week.

Bacon, who led the club with 11 sacks in 1980, didn't help his standing by missing a meeting and being late for practice last week. Yet rookie Dexter Manley, potentially a future pass-rush star, probably isn't ready yet to perform full time, and Mendenhall remains untested. That's why progress by Cook would be welcome news to the staff.

Only Dave Butz has been a consistent force along that line. Openly critical of last year's defensive approach, Butz has embraced Torgeson's fire-off-the line technique with impressive zeal.

"We just need more people to play like Dave," Petitbon said. "I guess I feel we'll be okay by the opener, but it would be nice to see more progress. Real nice."