There are a lot of things you might not know about the Washington Redskins defense, if only because a group of people stuck with a "consistent" label usually don't make loads of news.

For example, defensive end Dexter Manley resurrected a decade-old nickname the other day when he said the Redskins defenders "were a bunch of no-names." (Were it not for Manley himself, this might be true.)

Free safety Curtis Jordan prefers to call the defense "catalysts." When the offense wasn't going well, so the thinking goes, the defense led the team to a few victories.

Now, it helps out by keeping the score close early. The Redskins have allowed just 22 points in the first quarter this season, and that's better than anyone else in the National Football League.

The fifth-best defense in the league, it might be the only one with two rookie starters -- Dean Hamel and Raphel Cherry -- who were playing offense a year ago in college.

And only three running backs (Joe Morris and Gerald Riggs twice) have gained 100 yards on them in the past 42 regular-season games.

Succinctly, Coach Joe Gibbs said, "The defense has been our lifeline."

When the offense sputters early and often and the special teams don't find themselves until the second month of the season, someone's got to be around to hold things together.

Such is the role of the Redskins' defense in this 7-5 season. The defense dumped some high-tech strategy when the team started with a 1-3 record and went back to the basic, 4-3, man-to-man defense.

As Manley asked, "Who's gonna block (295-pound Dave) Butz one on one? Tell me, who?"

The result in the last eight weeks is a plus-eight turnover differential, compared to minus-12 in the first four games.

It's enough to make a defense think it's good, which, by the way, this defense does.

Jordan has been here four seasons and believes the '85 defense is the best of the Redskins' last four "as far as consistently stopping good offenses. I think we've played well all year," he said, "but this week will really tell."

On Sunday, the Redskins play the San Francisco 49ers (7-5) and quarterback Joe Montana at 4 p.m. at RFK Stadium. Montana has played very well against Washington the last two times they've met, throwing for more than 700 yards.

In the weekly ritual of inundating an opponent with praise, San Francisco Coach Bill Walsh said, "This Redskin defense looks stronger than ever. They've improved the defensive secondary and they're blitzing well. I don't think there's anyone better other than Chicago and a couple others in that category."

Assistant head coach/defense Richie Petitbon shuns praise in the midst of a season, but even he says he likes what he sees.

"We've improved a lot," Petitbon said yesterday. "We're making the big plays."

But he knows most of the Redskins' victories have come against inexperienced NFL quarterbacks: Warren Moon, Bernie Kosar, David Archer, Scott Campbell.

Montana is in another stratosphere.

Everything starts with the pass rush, led by ends Charles Mann (12 1/2 sacks) and Manley (12).

At their present pace of 42 sacks in 12 games, the defense would finish with 56 sacks, second-best in team history to last year's 66. "Someone's always going to be in the quarterback's face," said Hamel. "It's fun."

Good fortune has not been showered upon veteran strong safety Tony Peters this season. He suffered a pulled groin Nov. 10 against Dallas and was replaced the next week by Cherry. When Peters got well, he came back and found his job gone, taken by Cherry.

"I'm disappointed, but with me as a starter, the team was .500," Peters said. "With Raphel, we're batting 1.000. You can't knock that."

Peters, 32, in his 10th NFL season, said it was "inevitable" that he would lose his job. "I've had good years," he said. "I can't look back and feel bad. All I can do now is practice like I'm still starting and sit back and enjoy the season."

Running back John Riggins, who has been home with the flu the last two days, returned to practice yesterday. "He looked good and he said he felt pretty good," Gibbs said . . . Riggins took the first work at running back in drills, a good indication that he, not George Rogers or Keith Griffin, will start Sunday.

Left guard Russ Grimm watched films and then went home, missing his second consecutive practice because of a sprained left ankle. Gibbs said he hopes Grimm will be able to practice today . . . Left tackle Joe Jacoby (sprained right knee) practiced again and is expected to start against San Francisco . . . Defensive tackle Tom Beasley (sprained ankle) missed practice for a second straight day, while defensive end Steve Hamilton (hamstring) worked sparingly.

Wide receiver Calvin Muhammad, who sprained his right ankle on the Redskins' first kickoff at Pittsburgh and has been placed on injured reserve, said yesterday he hopes the Redskins will activate him if they make the playoffs. He is on injured reserve for a minimum of four weeks and probably will not practice for at least the first two.

"I'm hoping they'll bring me back," he said, "but I do think this was the right decision. They need a receiver who is 100 percent healthy. The whole season has been a disappointment for me," said Muhammad, who caught just nine passes for 116 yards. "I want to sit down at the end of the season and evaluate my whole situation."