He was too big to cry, but it hurt too much to pretend he didn't feel like it. Here he was, one of the best 18-year-old basketball players in America and the only one in this city of all-stars with no place to play.

"I'm in a state of shock," said David Boone, a 6-foot-6 guard who was San Francisco's most valuable high school player this year.

Last week, he was at the National Sports Festival when he found out that the college he had picked from the pack that offered him scholarships, the University of San Francisco, had decided to drop its men's basketball program because of alumni misconduct.

"I feel betrayed," said Boone.

Boone's basketball dilemma, and the implications of it, went directly against the grain of the amateur love fest that concluded Saturday night with the men's basketball title game.

For the last 10 days, the 2,600 athletes competing here in 33 sports, have produced something as close to the amateur ideal as competition at this level ever gets. And the fans in this Midwest city liked what they saw well enough to spend more than $1 million for tickets.

"You get kind of jaded from watching too much professional sports," said Ben Watson, an Indianapolis architect who spent two nights during the festival watching table tennis. "These guys bust their butt and there's no payoff."

Last week you could hear a full spectrum of answers to questions about winning, losing and how games should be played. Richard McKinney, a 28-year-old zen archer from Arizona, won a gold medal, then claimed that points and prizes meant little to him. Shooting perfect arrows was his reward, said McKinney. Stringing together a lifetime of perfect moments was his goal.

For a different perspective, there was Nolan Richardson of Tulsa, head coach of the men's South basketball squad.

"I've always said I would try to beat my grandmother," said Richardson, whose team won the gold medal. "It may not be the way we're supposed to go about things here, but winning is the American way. Not one single young man came here to just be a good sport."

It can be argued the McKinney can afford to be more laid back because he is shooting for personal satisfaction and they are trying to fast break their way to fame and fortune.

"I know the pro scouts are out there," said Michael Brown, 6-foot-9 center from George Washington University, a standout on the East squad that finished second here.

The amateur officials who put the festival's basketball program together welcomed the dozen professional scouts who came to watch. Their presence helped attract the best young players in the country. Only graduating high school seniors and college freshman were invited, to lessen the danger of losing players to the pros before the 1984 Olympics.

The more immediate goal for most of the players here was to make that 1984 team. With Bobby Knight, who has been nominated to coach that team, sitting in the stands for every game here, the players put on a playground display of individual talent to impress him.

"I have been introduced to a whole new vista in shot selection," joked the Indiana coach when asked his opinion of the run-and-gun, shoot-from-the-hip play that dominated the tournament.

Players such as Brown and Johnny Dawkins of Mackin came to this festival with reputations already established. So did Horace Broadnax, an 18-year-old from Turkey Creek, Fla., who will be attending Georgetown as a freshman this fall.

He picked Georgetown because he is a 3.2 student who wants to become an accountant and because Georgetown, he said, was the only school that didn't try to impress him by downgrading the programs of other schools.

"Nobody could say anything bad about Georgetown," said Broadnax.

Boone had heard bad things about San Francisco, where the basketball program there has been in and out of trouble with the NCAA since 1979. But, he says, "they told us wonderful things.

"I feel like they let me down,"Boone said.