The frailties of youth that have marked this Georgetown University basketball team all season were seldom more obvious than in tonight's 79-72 loss to Syracuse, a team the Hoyas had beaten twice, the last time only three days ago.

"What people don't understand," said Bill Stein, "is that John doesn't have the seniors to take the pressure off the kids. They'll get there. They'll be a great team, but right now they're still kids and all the pressure is on them--nobody else--to win games by themselves."

For a decade, Bill Stein worked at John Thompson's side as they transformed nothing into something. Now Thompson's old assistant is athletic director at St. Peter's College. The fire horse in him wouldn't stay in the barn tonight. He stood in a corridor at Madison Square Garden two hours before tipoff in the Big East Conference tournament.

And when it was over, Stein stopped to speak to Trina Martin, Thompson's office receptionist. "It's okay," he said.

Save in the minds of zealots who might have expected a national championship after coming so close last March, Georgetown has had a remarkable season that isn't over yet. The Hoyas can win some games in the NCAA, because the other side of that frailties coin is shiny with those dazzling bursts of virtuosity that tempt us to think the incandescent moments will last forever.

It's one thing to beat Syracuse when a freshman guard, in one of those moments, scores 31, as Michael Jackson did two months ago. Nor did it speak to Georgetown's tournament prospects this week when the Hoyas beat Syracuse with a second-half rally in a game that meant nothing in the standings.

Technically, even the Big East tournament means nothing, because the NCAA tournament is likely to invite three or four (maybe even five) conference teams to the national championships.

But now, a fortnight into March, the real weight of a team is determined. So the thumbscrews grow tighter. Veteran teams know what they can do under that pain. Kids don't know how it will feel. Apprehension walks with them, and there is no one to turn to for the comfort of a critical basket when the night is turning dark.

How many times this season have you seen the Hoyas, in critical situations, manage only a shot kindly described as ungainly? There is the sense of hurry in them, a sin as defined by St. John Wooden, who always said, "Be quick. But don't hurry."

Under pressure in the recent, shining past, the Hoyas turned to Steve Martin, who never hurried, or they gave the ball to Eric Smith, who moved it to Eric Floyd, who moved it into the basket.

Those fellows are gone now. They are the answer to the question, "What's wrong with Georgetown?" Well, the Hoyas could use a forward/center who can rebound. They could use a ballhandler who can get the ball to the inside men where they need it. Mostly, though, there's nothing wrong except that John Thompson's kids need time to grow up.

As good as sophomore Bill Martin has been, Thompson kept him on the bench the last 16 minutes tonight. The fellow working Martin's job, freshman David Dunn, had two chances to make critical baskets tonight. At 55-49, after he'd made two buckets to reduce Syracuse's 10-point lead, Dunn missed a wide-open layup. At 58-51, he missed a wide-open eight-footer.

This is not to criticize Dunn, but to show that freshmen miss wide open shots that seniors might make. And if those shots go in, who knows? Maybe Syracuse, beaten twice by the Hoyas in two months, would tremble in the remembered certainty of Georgetown's superiority.

It seems obvious that the Hoyas will be invited to the NCAA tournament. Not only did they finish second a year ago, they are 21-9 (and, because this is business, it is important that the TV folks like the attraction of Patrick Ewing).

"There's no question they should be in," said the winning coach, Jim Boeheim. "Especially with those young players, John did a tremendous job this season. It's tough to rely on young kids in a tournament like this. For them, it's their first time in this atmosphere. We have enough experience with our seniors that we should do well, and the veteran experience showed tonight."

"I knew I'd get caught in a hornet's nest," Thompson said, "because it's those seniors' last chance. Last year with my senior bunch, I told them it was their last chance . . . Syracuse was better than us tonight and they beat us . . ."

Thompson didn't like some things he saw tonight. He didn't like his team's careless passing in its half-court offense, a weakness it hasn't been able to correct all season, a weakness that leaves Georgetown nearly totally dependent on a full-court press and transition game to win. His five forwards had only five rebounds. Statistically the best defensive team in the Big East, the Hoyas yet allowed Syracuse to establish a run-and-gun rhythm that produced 65 percent shooting.

These are weaknesses not corrected in a week, and so it is safe to say Georgetown won't last long in the NCAA tournament. But Thompson, a patient builder of teams, said, "I'm not totally disappointed. We lost our concentration at certain times, but I'm not angry. I still think they're a good team."