Excuse the compliments, but Atlee Hammaker is not your typical 25-year-old major league sophomore, mostly because many people believe he has a future to rank among the top left-handers in baseball.

There's something else about the Mount Vernon High School graduate.

"He does some crazy, flaky things," said San Francisco Giants catcher Bob Brenly. "He's all business on the mound, but he doesn't take himself too seriously. He enjoys life out there. So if he comes off looking like a fool now and then--well, that's just Atlee."

For instance:

Charley Lodis, his college baseball coach at East Tennessee State, told Hammaker to protect his arm the night before an important game.

"He normally throws in the high 80s and low 90s, but on this particular day he had nothing," Lodis said. "After the game, I asked him what was wrong and I noticed his arm was all blistered."

It seems Hammaker had lubricated his arm, covered it with Saran Wrap and jumped into bed. "He said, 'Coach, you told me to take care of my arm,' " Lodis said.

His teammates still chuckle when recalling a game last season in Houston. Hammaker missed two steal signs before giving himself the green light. He stole second. Then he tried to steal third, but the ball was fouled off. About that time, Manager Frank Robinson put his cap on backward, failing in his attempt at looking upset.

"Sometimes he goes blank out there. He gets too wound up," Robinson said. "But that's true with most youngsters. So I wouldn't say he's your typical flaky, left-handed pitcher."

Call him your typical budding left-handed superstar. His personality matches his pitching--smooth and easy.

This season, he's been the National League's player of the week and the team's player of the month. He pitched seven perfect innings against the Cincinnati Reds (two hits for the game) and had a three-hitter against the Chicago Cubs. He has a 4-2 record and a league-leading 1.07 earned run average.

That's why they're cringing in Kansas City.

The Royals sent Hammaker, their No. 1 pick in the 1979 June draft, to the Giants in a package deal for pitcher Vida Blue and a minor leaguer before last season. Hammaker wasn't Koufax-like as a rookie (12-8, 4.11 ERA), but he's headed in that direction this season.

Col. Charles Hammaker retired in October from the armed forces, after 30 years of moving his family from Kansas to Okinawa and most points in between.

"It got me prepared for baseball travel," Hammaker said. "But it also made me extremely shy. Because of my shyness, sports became very important to me. It was a way to become accepted."

During the middle 1970s, when the family settled into its current home in Alexandria, Va., Hammaker ranked baseball with the measles.

"I wanted nothing to do with it," he said. "I loved basketball. I thought if I worked hard enough I'd be able to play professional basketball some day." He became a standout 6-foot-2 center for the Mount Vernon High School team.

"He was an outstanding leaper," said Gordon Hill, Hammaker's high school basketball coach, now the athletic director at Mount Vernon. "He held his own against much taller competition, averaging about 19 points and 10 rebounds per game, because he was so quick and intense. Baseball was still something before football and basketball seasons.

"I was the team's quarterback my sophomore year, and a scout from Penn State told me I had a chance to play college football some day," Hammaker said. But after a knee injury, he was advised to give up football. He was down to two sports.

And then there was one. He damaged his pitching elbow during his junior year, with medics at Walter Reed Army Medical Center giving the final rites to his baseball career. "I thought it was great," Hammaker said. "I had my favorite sport left."

Still, he recovered enough to pitch impressively his senior season in 1976. Hammaker got a four-year basketball scholarship to East Tennessee State, with the chance to dabble in baseball.

Three seasons later, he became the Royals' precious draft pick.

Now he's headed for stardom.