The natural selection process that winnows the weak from the strong has left Gary Roenicke at the top of the baseball heap, a major leaguer. Dreamers who want to be up there speak of the bigs as heaven. So Tony Larioni studied Roenicke out of a curiosity as to how the left fielder earned his ticket to paradise, sometimes called Memorial Stadium.

This was during batting practice yesterday when the Orioles came to town to play the University of Maryland. Larioni is a senior center fielder hitting .348. He's a straight-A student, an academic all-America. Fifteen years from now, when he's a dentist with 2.3 children and 1.7 Mercedes, Larioni will still say he'd have traded it all to be up there.

A TV reporter asked Larioni to tilt his cap back and let the sun shine on his face. Big leaguers do that without prompting. To the TV man, Larioni said, "It's a thrill . . . I hope to make the major leagues . . . The pitching will be as fast as some I've faced, but I imagine they'll spot the ball better . . .If I don't get drafted into pro ball, I'll go on to dental school."

Then, a wad of bubble gum stuck inside his lower lip, the way the big leaguers carry snuff, Larioni stood by the batting cage with his arms folded.

He is 6 feet tall, 180 pounds.

He saw Roenicke, 6-3, 200.

The kid didn't stare. A sidelong glance was enough. Larioni gets A's in chemistry subjects that can't be spelled with less than three z's. He learned in a peek all he needed to know.

"Those guys," he said, meaning Ken Singleton and Eddie Murray and Cal Ripken and Gary Roenicke, all 6-3 and 200, "are gigantic."

One imagines Fleming announcing penicillin with the same tone of wonderment.

"They're awesome," Larioni said. "Even the little guys--Al Bumbry and Lenn Sakata--are so strong."

Now this is a sophisticated, bright young man who has played baseball in Yankee Stadium and Fenway Park. He has had a bat in his hands since age 4 or so, when his father, Tony Sr., showed him how he used to do it. Every summer, Larioni plays in a good college league. He was MVP two summers ago. He has played with quality players.

But not with big leaguers.

"You just don't realize how big they are until you're right next to them," the dreamer said.

However great Tony Larioni imagined the distance to be from college ball to the big leagues, he now knows it is three times that far.

"So much smoother," he said of the Oriole hitters. "So much bigger, so much stronger. They just flick the bat and anything they hit just jumps off the bat. I'm a smaller guy, so I have to get everything into a swing. They just flick the bat so easily."

The Orioles won the exhibition game, 12-6. They hit five home runs. Larioni went zero for four against two Class A farm team pitchers. He lined out to shortstop his first time up, then cracked a sharp one-hopper at the second baseman the next time.

For him, the difference between college and pro was evident the very first pitch.

"They spotted the ball so much better," Larioni said. "That first pitch, a strike right on the black. And they make the plays. I hit the ball right on the button, right up the middle--and the shortstop is already moving to catch it. I said, 'Damnnnn.' "

Tony Larioni Sr. hit .500 in high school, his son said. The father was married at 16 and went to work as a carpenter to raise his family. Same thing with Tony Sr.'s father, a good ballplayer who quit to provide for his kids. So now, Tony Jr. says, his dad and granddad do whatever they can to keep him playing.

"Hopefully, I'll get a chance to get up there," Larioni said, meaning up there in paradise.

It might be easier, he thinks, if he didn't have all those A's in chemistry and such. To keep that up, you have to study late at night. You come to the ball field worn out. He thinks that may be why he hits .360 in the summers, but .320 at College Park.

He'd love to get away from the books and concentrate on baseball, the way those big guys do.

"I don't want to get my hopes too high about the pros," Larioni said. "That can lead to a big letdown. But I know I'm better than some guys I know in the pros. If I ever got a chance to concentrate just on baseball, I'd improve. I know it."

At the same time, Larioni, after a day's play on the same dirt and grass as the giants up there, was as realistic as a dreamer ought to get.

"I feel like I'd be able to hit with anybody," he said. "I can field with anybody. I'm not big and I don't have blazing speed. But if all I had to do was play ball, I'd improve on everything a little bit."

Would he, say, sign with a team and go to its lowest-classification farm team?

"I'd go. Give me a pair of spikes and some bubble gum, I'd go."