The Redskins ought to be dramatically better this season. For the first time since the George Allen years, it is almost impossible to cut their roster below 15 1/2 players. Which means that bottom liners among us are expecting nine victories, in addition to a thrill-a-second offense.

That might seem unreasonably lofty to anyone who endured more than a half of today's 19-10 loss. Players with pocket-sized bruises will insist otherwise, but the Redskins did not lose to any budding juggernaut here. The New England Patriots minus Russ Francis, Sam Cunningham, Stanley Morgan and Harold Jackson are like the American Patriots playing at home against the British without George Washington and Benjamin Franklin.

There is a curious logic afoot among Redskin thinkers this year, especially owner Jack Kent Cooke. From a preseason team last year with no speed and no fullback, he thought a Super Bowl appearance likely. With enough runners to relegate last season's most dependable back, Clarence Harmon, to little more than special-teams action, anything that approaches break-even apparently will be satisfactory.

It should not be.

The offense has five better players this season than it had last: John Riggins, Joe Washington, Terry Metcalf, Mark May and Russ Grimm. Young and raw as they are, rookies May and Grimm are more talented than the Holding Company that passed for an offensive line a year ago. Top draftees, they are supposed to be where they are, starting.

We will give Coach Joe Gibbs the benefit of the doubt, assume he has held back tons of trickery from the recent exhibitions and will unleash it Sunday against the cursed Cowboys in RFK Stadium. Lately, a good deal of the offense has been surprisingly offensive -- and familiar.

Today, the Redskins had first and goal from the Patriot two, and were forced to settle for a field goal. In one series, they ran on second and long and again on third and long. There were three first downs the entire second half, with the most productive passing combination being Matt Cavanaugh to Mark Murphy.

One almost expected to look up from a third helping of No-Doz and see Benny Malone taking a handoff and pawing his way to the line of scrimmage in the same amount of time most other runners take to go 40 yards. Some of the 1981 reserve receivers drop passes as regularly as the 1980 bunch.

The inexperienced, undermanned and injury-riddled offensive line has been analyzed more than money market investments. Few teams win more than a few games without blockers who regularly dirty the trouser backs of defensive linemen. We'd hoped for a bit more from Gibbs, that somehow he could find a way to cover for a mediocre offensive line the way the defense has overcome similiar problems in prior years.

This preseason the Redskins have scored one more point than they did last preseason, 66-65. But is quarterback Joe Theismann worried, quaking that he might get buried alive in Philly or the Meadowlands? Naw. Theismann would be publicly positive if the Lennon sisters were blocking Randy White and Too Tall Jones.

Let's hear him out anyway:

"The attitude is so different this year from last, 150 percent better. Last year, with the John thing (Riggins bolting training camp and then retiring), it was so unsettled. It was always: 'What happens if . . ?' This season there is no 'What happens if . . .'

"I've always said 85 percent of this game is mental, that if you have a good mental attitude you're on the right road."

Joe, some what-happens-if emerged on the other side of the dressing room today. They were walking, sort of, and had names. Alarmingly, they wore straps and a cast. What if Mike Nelms cannot return kicks with that broken thumb? What will be the implications for the special teams, the carryover effect on the offense if Terry Metcalf must risk his neck under punts?

The what-if with Brad Dusek was considered even before the preseason, but for another reason, his back instead of the shoulder dislocated today. Still, the Redskins' 3-1 success this preseason has been largly due to the defense and special teams. When has this not been true? Since Otto Graham?

One of the bad assumptions most fans make about this time each season is that their heroes, every one of the 45 players who survive the final cut, actually can play, or cannot be replaced rather easily, like a faulty or worn part on an automotive assembly line.

A team blessed with as many as eight superior players, cornerstones, potential all-pros, Theismanns and Art Monks, is rare. Anyone who can blend 15 to 20 players a cut above the ordinary around those pistons usually drives comfortably into the playoffs.

It says here, through no especially grand scientific analysis, because none really is possible, that the Redskins have a total of 15 1/2 players who cannot be replaced without severely damaging the team. Arguments will be accepted over whether Tony Peters, Coy Bacon and some others deserve to be upgraded from one-half.

A year ago, the Redskins had perhaps 2 1/2 players on offense you knew could man their positions for most other NFL teams. This year, there are twice as many, or enough for Tom Landry to worry into the early evening for a change.

"Some good things early, and then we lost it somewhere," said Gibbs, softly. "The poor second half carried over to the kicking team and eventually over to the whole team."

"If you've gotta get knocked down," Theismann chirped, "the last exhibition game is the time for it. It gets everybody back to earth."

But not from demanding an entertaining trip at least half-way to the moon.