The Redskins fed all types of statistics into their new computer this week, hoping to find out why they seem to break down almost every time they threaten to score a touchdown this season.

The results of the computer study have left Coach Joe Gibbs and his staff seeing red the last few days.

"We found out that once we got to what we call the 'red zone," which is inside the opponent's 20, we were the worst in the league in coming away with points, especially touchdowns," said Offensive Coordinator Joe Bugel. "So all we've concentrated on since Thursday night is how to correct the problem. We've been thinking nothing but red zone, zone, zone, red zone. We've got to do better there if we are ever going to score consistently."

How much the Redskins have profited from this concentration on the red zone could be a determining factor in today's 1 p.m. game against the San Francisco 498ers in RFK Stadium (WDVM-TV-9).

This is an opponent the Redskins feel they can beat, even if the 49ers are 2-2 on the season, compared to Washington's 0-4 record. The oddsmakers, in fact, make the Redskins two-point favorites.

But Gibbs and his players also realize the only was they'll ever win a game is to start scoring in bunches instead of letting drives fizzle because of penalties, turnovers and other breakdowns.

"We need to get off to a quick start, to get our fans on our side," running back Clarence Harmon said. "Otherwise, I think the boo birds are ready for us. They won't be very patient. If we get close early, we better score."

The Redskins have been splendid this season running up impressive statistics. They lead the National Football Conference in total offense, and no team in the league has been more productive passing the ball. But they also are averaging only 15 points a game, mainly because they have botched up half of their 18 scoring opportunities inside the 20.

"Your margain of error is a lot smaller once you get inside the 20," quarterback Joe Theismann said. "So one mistake there can kill you, but the same mistake at midfield isn't as damaging. We've worked on scoring this week and I think we are ready to do better. The offense is a lot more familiar to all of us now, so there should be less conscious thinking and more reacting. And the more we cab rely on instincts, the more effective we will be."

Gibbs said he has prepared a special package of plays for his team to run once it reaches the red zone. He has tossed out the less-effective calls, polished up his best plays and added a few new wrinkles.

"What amazes me," he said, "is that we have completed seven of 13 passes inside the 20, which is a great percentage. But we are averaging only 2.5 yards a run. We need to run better once we get closer."

Injuries could make that difficult. Fullback Wilbur Jackson, the Redskins' best runner, won't play and halfback Joe Washington is doubtful. That leaves fullback John Riggins, who had been beaten out by Jackson, as the team's main rushing hope. If Washington can't get its ground game untracked, the 49ers will be able to tee off on Theismann.

However, Theismann is sure to spend a good portion of the game testing the 49er secondary, which starts three rookies, including No. 1 draft choic Ron Lott. The 49ers are 11th in the conference in defense, ninth in pass defense, giving up 208 yards a game through the air. Theismann averages 313 per game.

With kicker Mark Moseley still having leg problems, the Redskins have added incentive not to settle for field goals. They also could benefit from the kick-return work of Mike Nelms, who is almost 100 percent.

Gibbs has another reason for hoping his offense functions consistently. His defense has four starting changes due to injuries and will have difficulty holding up if San Francisco is allowed to control the ball with its short-pass attack.

Linebacker Brad Dusek and tackle Wilbur Young were activated from the in-season injury list yesterday, replacing linebacker Kevin Turner and quarterback Mike Rae, both of whom were waived. Young and Dusek, along with rookie end Dexter Manley (for Mat Mendenhall) and cornerback Jeris White (for Lemar Parrish), will start. Young especially could play an important role, since he is an accomplished pass rusher, something the Redskins have been lacking.

San Francisco has managed to avoid major injuries this season. Halfback Paul Hofer (leg pull) is the only questionable player for the game. But his absence will weaken an already shaky rushing attack.

The 49ers shuffle runners constantly, although Ricky Patton (211 yards) gets the majority of the carries. Fullback Earl Cooper, who caught 83 passes as a rookie last year, has not played well this season and now is being removed on short-yardage situation.

Quarterback Joe Montana, however, has played well. He is the NFC's leading passer (67 percent completion rate), throwing for seven touchdowns and only four interceptions. His favorite receiver is speedy Fred Solomon (17.9 average), who usually is good for at least one big play a game. And if foes double-team Solomon, Montana can turn to his other outside man, Dwight Clark, who caught 82 passes in 1980.

This is the third year of Coach Bill Walsh's rebuilding program, and the 49ers are even younger than the Redskins. They have beaten Chicago and New Orleans this season, and lost on the road to Atlanta and Detroit.

In fact, San Francisco's away-from-home record under Walsh may be the most encouraging statistic the computer discovered for the Redskins this week. Of 18 road games, the 49ers have won only two, beating just New Orleans and the New York Jets.

Punter Mike Connell has the flu, but Gibbs said he thought he would be okay today. Connell also will handle kickoffs . . . Ron Saul probably will start at left guard, with Russ Grimm available . . . Ray Wersching, the 49ers' regular place kicker, is on injured reserve with a leg pull.