"The only person really soiled with trade I ever stumbled on in old New Hampshire was someone who had just come back ashamed from selling things in California." Robert Frost, "New Hampshire"

Often the fear creeps up on Mike Flanagan that slowly, imperceptibly, insidiously, he is being soiled by baseball.

Then the Balitmore Oriole southpaw thinks back to his boyhood in New Hampshire, the long bicycle rides of his youth with his snowwhite collie racing beside him, and he feels secure once more, certain that he always will be a New Hampshireman first and all else second.

"If you know where you came from, you'll always know where you're going," says Flanagan, who leads the American League in victories with a 17-7 record.

Flanagan, 27, never forgets, never wants to return home ashamed of what he has become.

"my wife loves Robert Frost," says Flanagan. "One day we were riding around the back roads of Dairy (N.H.) and came on a little ramshackle farm where Frost had spent four years.

"We made a special trip once to Bennington, Vt., to see Frost's grave. It you have to die, it's the most beautiful place to be buried . . . on a hill with the foliage at its peak in all directions."

Flanagan feels most at home on hills, either on the pitcher's mound where he is a studious craftsman or on those other hilltops where he has always lived and felt clean.

"I grew up in Manchester on a hill over a lake near an amusement park," says Flanagan.

"I remember cycling those great distances, 10 or 12 miles, just to gather up enough friends for a game -- up and down those hills with Whitey running beside me.

"I've thought back to those days many times. Sometimes my dad (who pitched in the minors for the Red Sox) gets bored and wants to move. I tell him, 'You don't know how often when I'm flying to all those big cities I just long to look out our backdoor window at the lake.'

"You don't appreciate those hundreds of times that you've been fishing, looking up at the White Mountains in your backyard, until you've been away for six years."

Those thoughts of another place never seem far from Flanagan, who has just finished building a hilltop house in Amherst, N.H., for his wife of two years, Kathy.

"I picture it snowing and I'm looking through all that glass down at a little town," says Flanagan. "What am I doing? I think maybe I've felt real energetic and my feet are propped up."

Flanagan, either pitcher or person, only makes sense as seen through his prism of deep-rooted New Hampshire life.

"My grandparents always lived across the street. Now I go back and my friends have built homes on the same plots as their parents. Another generation has just sprung up."

Flanagan deliberately has stayed hidden during his three years as an Oriole star, although teammates know him well.

"I call him 'Alan Alda' because of that sly New England wit," says John Lowenstein.

"Flanny is sort of a secret crazy, like the guys on Saturday Night Live," says Ken Singleton. "He's calm and laid back and invisible; then, for about 10 seconds, he's hilarious. He'd make an excellent Killer Bee."

Opponents and the public hardly see below the camouflaged surface: long, lanky hair, unshaven before he pitches, deliberately styleless and baggy uniforms that make him look like a menacing Sal Maglie.

"Pitchers are tricky. They don't want you to know who they are," says Kansas City's Hal McRae. "All I know about Flanagan is that he's got guts."

"Taking all four of his pitches together, he probably has more total stuff than any pitcher in the league," says American League All Star Game starting catcher Darrel Porter of Kansas City.

Boston's Jim Rice simply calls Flanagan "the toughest of 'em all."

Yet Flanagan is perhaps the least-known and lowest-paid star in baseball, relative to his statistics. He is thoroughly comfortable with both distinctions, and even cultivates them.

"I sidestep publicity. It's not hard," says Flanagan, grinning. "Two weeks ago, the Sporting News had a full-page cover picture of me. I turned inside to read about myself . . . I think I was mentioned in one sentence. I got a kick out of that."

If pressed, he will admit that, "I suppose I'm vastly underpaid. It doesn't bother me. I'm a jeans person. I roomed with Wayne Garland for a year and he seemed like a happy man, then. Now he's rich, injured and not too happy. "I talk to Ross Grimsley," says Flanagan. "He says in Montreal they call him the $300,000 disappointment."

Flanagan signed a five-year contract with the O's in 1977 when his major league career record was 5-14.

"Rather inauspicious," says Flanagan, a graduate of the University of Massachusetts in Amherst."I was struggling badly. But they had confidence in me and signed me to a five-year contract. I appreciated it.

"My desires are modest. I like conservative things. I see people back home making $16,000 or $20,000, and they're happy.The people who rent my house pay me $170 a month. That's a lot in New Hampshire.

"Actually, I'm glad that money and notoriety haven't cut me off from my old friends. My buddies still treat me like they used to . . . maybe like the high school star jock. But it hasn't reached the point where this fear of someone else's success comes in and poisons things."

Pinned to Flanagan's locker stall is a photo of one of those old buddies -- stuffed in a streetcorner trash can. Next to it are Flanagan's portraits of his teammates and himself -- bubble gum cards with penciled-in mustaches, beards, crazy hair and crossed eyes. Heads are attached to wrong bodies.

Tossed in among Flanagan's ever-present jeans, T-shirts and moccasins is a phoney Washington Post newspaper headline that says, "Pope Purchases Orioles: Birds May Play in Rome Next Year." Next to the pitcher's glove is a cartoon captioned, "If an eel lunges out . . . and it bites off your snout . . . that's a MORAYYYYY . . . "

A news clipping lists his "least favorite things" as "kittens that grow up to be cats" and "mistaking a cup of tobacco juice for a Coke."

"I really take baseball as seriously as anything in life, although that bothers me," he says. "It's so easy to get out of contact with the world. It's culture shock when the season ends.

"A bell rings in me at 4 p.m. every day telling me to be at the ballpark. I just tell Kathy that I'm going to fish until that bell stops ringing.

"Then I read everything -- anything that puts me in touch with something tangible: Outdoor Life, mechanics, carpentry, fishing, hunting, short stories, science fiction."

Flanagan's pitching record has been 48-24 since June, 1977 -- the best in baseball other than that of Ron Guidry -- yet the 6-foot, 195-pound athlete never feels entirely at home with his profession.

"It's been a frustrating life, not like I dreamed about as a kid.My dad never told me the hard side. Or maybe I just didn't hear.

"He prepared me perfectly for life on the field. I once struck out 31 men in a high school game. He never even said, 'Nice game." He knew it was all too easy.

"He knew about getting hit by line drives and playing hurt for months at a time and 14-hour bus rides in the minors.

"I could never understand why I was a little better than other guys, why I kept moving up the ladder even though my outward personality was so like my mother's, real relaxed. I finally realized that deep inside I was the way my father made me -- never satisfied, always expecting to become much better."

It is the hours away from the park that often seem barren to Flanagan -- almost a cheat in his life of exaggerated highs and lows.

"In summer, you seek boredom; then, after the season, you have too much of it," he says. "You're so excited to see your old friends in the winter and do things. Then you realize it's Monday and they'll have to work the next five days.

"We all face a split life. Ther's either not enough time for anything and the game consumes you, or there's too much time and nothing to do with it."

Who, at 27, can count the cost or resist the game? The thrill of sudden revelations and delicious victories is at the finger tips, as close, in Flanagan's case, as the discovery last month of the long-sought changeup.

"Scotty (McGregor) taught me," says Flanagan. "I went out and pitched a three-hitter against K.C. on 89 pitches with nine strikeouts. Best of my life. Better than a no-hitter. Since then, except for one start when I had so much stuff I couldn't get it over the plate, I, well, I've hardly been touched."

In his last four starts, Flanagan has struck out 38 in 38 innings while walking just six. Only one major problem stands between Flanagan and the sort of final quantum leap that might one day lead to the Hall of Fame: the mystery of the early knockout.

In seven of his 30 starts this year, Flanagan has lasted only a cumulative 12 innings while being crushed for 37 earned runs -- a 21.16 ERA with an 0-4 record. In his other 23 starts, his ERA is 2.04 with a 17-3 record. That all-or-nothing trend, although not quite so pronounced, runs throughout his career.No explanation has as yet, been found.

It is, of course, appropriate that Flanagan, New Hampshire's child, should have a unique and puzzling flaw.

"Just specimens is all New Hampshire has, said Frost, "one each of everything as in a showcase which naturally she doesn't care to sell."

Certainly, in baseball's showcase, Flanagan is a unique specimen, one that, if he has any say in the matter, will never be soiled or up for sale.