If he were the coach of any other 10-6 team in the National Football Conference, Joe Gibbs would spend most of Christmas Day at the office, just as he has done the last three years, getting ready for a playoff game.

But, being the coach of the '85 Washington Redskins, he has the day off.

"What do you do on Christmas?" he asked earlier this week, laughing. "I've got to go home and decorate the tree. I'll probably tip it over."

For Gibbs, the past few days have brought a rush of mixed feelings. He was disappointed. He was excited. Occasionally at the same time.

It's easy to figure the former, considering that two seasons ago, this team went to the Super Bowl, and this season, it just went home.

But excitement?

At Redskin Park Monday, as the players packed up and the coaches cleared their desks for a little vacation, it was as if someone pulled the plug too soon on the season.

"There are times you get tired during a season, but this is not one of them for me," Gibbs said. "If we had made the playoffs, we had nobody hurt, everybody would have been ready.

"Last year, if we had gotten into the championship game (Washington lost to Chicago, 23-19, in the first round), I don't know who we would have played on the offensive line."

Gibbs believes the '85 Redskins were on a roll, and who could argue? They won five of their last six games after beginning with a 1-3 record. For the first time in three years, they won the final game they played. They did it with loads of young players and went without several injured veterans for huge chunks of the year.

"When you finish like this, everybody feels, 'Hey, if we could have gotten to this position a game or two earlier, we'd have been in the playoffs,' " Gibbs said.

"I think it gives 'em confidence next year. They look around and see what the potential is as a team. The young guys that stepped in there, the Barry Wilburns, the Raphel Cherrys, the Dean Hamels, the Jay Schroeders . . . They also look around and say, 'We could get (injured guard) R.C. (Thielemann) back, we can get back maybe a Bob Slater (injured defensive tackle) . . . "

The combination of old and new, sans injuries, could make the Redskins "an excellent football team," Gibbs added.

Almost everyone in the organization breaks the season into two parts: the 5-5 beginning and the 5-1 conclusion.

As owner Jack Kent Cooke said, "They found their niche at that point."

The offseason will be filled to the brim with reasons why it took 10 games to find it, and personnel decisions likely will be made with that in mind.

But 1985 follows an emerging pattern of the Gibbs years: The Redskins have a 7-8 record in the first three games of each of Gibbs' five Washington seasons. They are 15-0 in the last three regular-season games of those five years.

This contrast bothers Gibbs. He flat-out blames the slow start for missing the playoffs.

"It put us in a real bind," he said.

Last summer, Gibbs tinkered with the team's training camp schedule, hoping to come up with a better beginning.

So what do the Redskins do? They lose to Dallas, 44-14.

"Two things pop in your mind," Gibbs said. "How can we do it late? And how can we start like that? I think that's probably got more to do with me than it does with anybody else.

"I've got to find a way to correct that or it's gonna bury me."

Looking back, he called this season "a trying year."

"It was a harder year for me . . . because of a lot of things that happened. There was more change on our team this year than we've ever had . . . It definitely was a year of more transition; there were more things happening."

He is as alarmed as anyone that the Redskins have slid from Super Bowl champion to conference champion to division champion to nothing in four seasons.

"That's definitely not the direction we want to be going," he said. "But let me say this: when you get to the Super Bowl and win the Super Bowl, there's probably only one other way, right?

"From the very first year, we never said we're in a building year, a rebuilding year, a transition year. None of that counts. We want to get into the playoffs, and we failed in that objective."

Cooke, reached at his Middleburg, Va., office, remains very pleased with Gibbs' five-year package.

"Fifty-one and 22 (Gibbs' regular-season record) is pretty damn good," he said.

Cooke, who advises Gibbs and General Manager Bobby Beathard but does not make personnel decisions, said he would not call for any changes to be made to the team, "other than those that come as the result of attrition."

He would not elaborate.

It is considered likely that among those making decisions on their Redskins careers (or having decisions made for them) are quarterback Joe Theismann, running back John Riggins, kicker Mark Moseley and strong safety Tony Peters, all long-time NFL veterans.

But the nucleus of the Redskins is expected to remain about the same. Gibbs said he views the large number of four- or five-year veterans on the team as a "stabilizing factor."

"They've proven they can win football games," he said.

They'll have to win more against a potentially tougher schedule (the Redskins will play the entire AFC West in addition to the NFC East) to suit Gibbs' and Cooke's tastes in 1986.

"I'm looking eagerly forward to next year," Cooke said.

Gibbs is, too, but with a note of experienced caution:

"You never know what the season is gonna have in store for you."