Years ago in Roosevelt, N.Y., after practice had ended and everyone else had gone home, Ray Wilson would watch Julius Erving explore the limits of his imagination. The coach thought the skinny kid at the other end of the court was wasting his time, fooling around with those crazy shots. "I said, 'I don't know why you're throwing that junk up there, son,' " Wilson said. "I was putting limitations on him. But Julius wasn't allowing any limitations to be put on himself."

There were five minutes left in the third quarter of a playoff game at the Spectrum not long ago. Erving had the ball down low, to the left of the basket. Long arms engulfed him. Erving glanced right, then left. There was no place to run, no place to hide. He shrugged almost imperceptibly, and as he did, flicked the ball over his head, off the glass and through the basket.

Why are you "throwing that junk up there, son?"

"That?" he said, after the game was over. "That was just a layup--a left-handed layup. It wasn't that hard."

He spun to his left to find his comb, and spun back, laughing warmly in your face.

Some people have an impact. With Julius Erving--The Doctor, to you--of the Philadelphia 76ers, it is more appropriate to use the word (so much in vogue) as an active verb. Give him the ball. He impacts on your consciousness. He impacts on kids who dream of growing up to be Dr. J.--or even Dr. Chapstick.

"Louie Carnesecca (coach at St. John's) used to compare the way I play to poetry in motion," he said. "It starts with a fundamental approach to the game and then taking different things out on different tangents, and not really knowing where I'm going. When I'm on the floor, I generally look for daylight. Finding that daylight, I try to fill up that space with myself and with the ball and darken that area."

You can talk about dunks and hang time and vertical leap, but those standards are really much too earthly for Erving. As John Thompson, the coach at Georgetown, says, Erving now sets the standards by which people are measured; and that is the definition of greatness.

When coaches talk about his impact, they speak about an athlete who has not only opened up the game but opened up the mind. They talk about a man who may be easier (and better) to emulate off the court than on it, as Jack Bruen, of Carroll High School, says. They talk about an idol worth idolizing.

John Thompson: "Unfortunately, with someone like Julius, it's always interpreted as being physical ability. There's plenty of people who can jump as high, and who have hands as big, who didn't have the imagination and creativity to do the things he's done."

Gene Doane, Seneca Valley: "He's had a tremendous impact, mostly positive. (He's) opened up their (high school players') imagination to the romance of the game. . . He's made them aware of the celestial type game that a player can play."

Wil Jones, University of the District of Columbia: "Julius was very necessary for those free-minded individuals who like kids to go as far as they can with their imagination in basketball."

Morgan Wootten, De Matha: "He's had a fantastic impact on the game. When someone has impact, it can never be 100 percent good. He's 99 percent good . . .Larry Bird is a more complete ballplayer. Julius is the perfectionist. Dr. Naismith invented the game. John Wooden perfected it. Julius Erving has taken it to a new dimension never thought possible."

All this embarrasses Erving a little, although surely he's heard the praise before. He counters with deliberate bravado. "You've got to dare to be great," he said. "Nothing ventured, nothing gained. I didn't know for a long time what put that inside of me. But it sure got boring shooting a layup the regular way."

Even his laugh has a wingspan.

Creativity? He nodded.

"I wouldn't say I was alone. Others, too, have brought imagination to the game . . . I think I've probably been kind of a cross-over player, blending the things usually attributed to a smaller man (with) the things the bigger guys do . . . I cross over both ways, down-scale and up-scale. In doing so, I've become an exponent of all-around play rather than specialization. I do a little bit of everything and a lot of some things.

"Have I changed the game? I think I've had an impact. Before, it was inconceivable that a guy 6-foot-6 could slam dunk the ball 150-200 times during the season. That's something seven-footers did. So the slam dunking part is not necessarily an innovation, but for a player my size, it's broadened the way people think of forwards, the standards they have for forwards and big guards. It hasn't been a well-thought-out thing, obviously. It's something that just evolved."

Gerry Gimelstob, the coach at George Washington, says Erving is an example of "the increased efficiency of sports. Maybe Elgin Baylor made Erving possible and now Julius will make someone else possible."

Who was Erving's Erving? No one person, he said. "I liked Baylor."

Today, most everyone on the playground wants to be Dr. J.

"If you watch high school kids, they all want to come in with the ball one-handed, move it around in the air, and slam it down," Doane said.

"I think it creates more of a problem at the junior high school level, when the coordination is not up to their skill level . . . He's in his formative years. You're trying to get the kid to make a forward pivot and it's a disaster . . .He only wants the flashy, the pizazz, the icing on the cake."

John Senuta, coach at Ridgeview Junior High School, says, "They are in awe of the pros. They try to follow in their footsteps at an early age. We have to go back and teach, and reteach them that those things aren't important."

Erving couldn't agree more. "As a pro basketball player, I am an exhibitionist. I am not a teacher. When they see me play, they see me exhibiting the skills that I have. . . There is little to be learned by watching it. That's for entertainment."

So what about the kid who is out there trying to slam the ball when he hasn't mastered a layup?

"That particular kid probably has the same approach to all the things he does," Erving said. "Rather than taking the schematic that has already been laid out, he wants to take the short cut. If he's taking the short cut, that's more a personality problem that has to be dealt with in an all-around sense rather than just telling the kid, 'You can't dunk the ball.' "

You've got to have "due process," Erving said. "Getting to the end itself is not a cure-all. You've got to go through the steps in order. That's not something that's going to be revealed to you all at once, either."

Ed Tapscott, the new coach at American, says he has three Dr. J. worshippers on his team. "Do I see them wasting time? Occasionally. Do I tell them not to do it? Certainly . . . Sometimes, you have to tell them, 'Take that shot and put it in the trash can.' "

But coaches say Erving's impact is overwhelmingly positive. "What's wrong with reaching for the stars?" Wootten said.

Erving did.

"Julius had dreams," Wilson said. "We were afraid his dreams were too big. But if you don't have 'em, you don't attain 'em . . . You see a whole lot of kids now doing strange things. As coaches we ought to give them the right to fail and to try and come back and succeed. Julius taught me that."

After all, Wilson recalled, Erving was just 6-foot-3 when he graduated from high school. "I said, 'Well, he's going to be just a good second guard.' "

"If a million kids want to be Dr. J., I say hooray," said Red Jenkins, coach at W.T. Woodson. "Maybe 10 out of a million will approach his ability level. But you gotta have things that drive you inside. He provides that for an awful lot of kids."

Johnny Dawkins, the all-Met guard from Mackin, who will attend Duke this fall, said, "At one point in time, I wanted to be Dr. J. But as I grew up, I didn't get as big as him. I realized I couldn't be him."

Dawkins was in ninth grade at the time. "It didn't upset me," he said. "It made me work harder at the things I do . . . There's always that few that never realize there's only one Dr. J. They keep on and on, and they don't understand why they didn't make it. They really hurt themselves that way."

Most young players (unless they have weak coaches, the coaches say) begin to realize their own potential by being themselves. It's important, the coaches say, to give kids time to find out who they are and who they aren't.

"Basketball is a way of expression," Wilson said, "a way of hiding your problems and everything else. You've got to give a person time to take care of those needs, too."

Sometimes, Dawkins says, "I'll try a weird shot, something Dr. J. would try. Why not? If it goes in you're a hero on the playground. If not, there's no coaches out there."

Erving is always there. Doane tells his players that if The Doctor can use the glass, they can use the glass. Paul DeStefano, the coach at Mackin, tells his players that they shouldn't worry if they aren't heavily recruited by big-time basketball schools. The Doctor wasn't, either.

Wootten reminds kids that Erving "doesn't try to be spectacular." He only plays within his ability, Wootten says. "All he does, like any smart player, is strictly what's necessary. But his capacity is greater than any player alive."

Thompson tells his players about the time there was a brawl on the floor and the camera was focused on Erving. "Julius was sitting in the middle of the floor, watching it," Thompson recalls. "He was totally under control . . ."

All the coaches tell their players how well The Doctor speaks; how well he carries himself on and off the floor; how he gives and commands respect. They say he's the greatest one-on-one role model around.

"I try to reinforce the impression Julius Erving makes on the world," DeStefano says.

Erving is accustomed to the role. "In every situation, any type of profession you look at, the thing that strikes you first is the glamor and the glitter, the positive things. . . In sports, there's a downside and negatives. When you're on the outside, you don't often acknowledge them. In being a role model, I try to devote equal time to the negative things, so they can get a clear idea of the situation. That's when the ears really close up."

When the 1980 all-star game was played in Washington, Spaulding filmed three TV commercials at Mackin. "Not only did Dr. J. come, but so did Larry Bird and Magic Johnson," said Dawkins. "Everyone else came tight and quiet. He promised to remember us if he met us later. A lot of guys aren't great personalities except on the court."

Erving did not leave until "every kid was satisfied," DeStefano said.

Dawkins wanted to check to see if The Doctor's hands were really as big as everyone said, and he did. "I got to shake his hand," Dawkins said, still excited two years later. "It just swallowed up my little hand.

"He wasn't shy at all. He didn't act like he was tired of children. I asked what he did to get to be so great. He said, 'A lot of hard work, a lot of hours on the playground' . . . We were hanging on every word. I didn't forget a word he said for two weeks: 'practice, practice, practice.' "