DURING HIS PHENOMENAL rookie year in 1976, Mark Fidrych shied away from the self-congratulatory stardom of major league baseball. When asked about his pitching with the Detroit Tigers, he would smile and say, "It's no big deal." When agents urged him to cash in on his success financially, he would answer, exuberantly, "I play baseball." And the fans loved him, they had never seen anything like him. Tall, gawky, like a stork out of water, Fidrych stepped on the field with a flurry of limbs, hair and mutterings. Not since Dizzy Dean bamboozled his way into the national heart had any one personality so captured the imagination of baseball.

The media was at a loss to explain the Fidrych phenomenon, though they attempted to conceal their puzzlement in a blitz of coverage. They asked Fidrych questions, but they werv unsure whether the inchoate answers they received constituted answers. They dug into his past life, talked to his cigar-chomping high school coaches, asked his mother his favorite dish, and visited his old stomping grounds at the gas station. Time and Newsweek featured him with their usual platitudes, running on about the "new baseball fad" or "the teenage symbol." But the more the media mucked and raked, the more they betrayed their frenetic ignorance. They could not peg Fidrych. He seemed content to sit up in his apartment, with an old stereo and a generous supply of Coors beer, nonplussed by the publicity. Soon the sportscasters' favorite line (crooned by the likes of Howard Cosell) implied that Fidrych had a few screws loose upstairs--that he was a bit of a flake, a nut, a loony.

But the fans, the true students and lovers of the game, weren't fooled by this nonsense. Intuitively they understood that Fidrych was a ballplayer of the old stamp, the kind that played before the game took on the attributes of a big-money promotional sport. He wasn't another imposter like "Catfish" Hunter, whining about his next million dollar bonus. Nor was he a giant-sized "hot dog" (alias superstar) like Reggie Jackson. He played ball with spirit and enthusiasm, albeit a little oddly--with a sincerity that caught the fancy of all who watched him. And the fans flocked by the tens of thousands to see him, to cheer their hero. The oldtimers said they had never seen anything like it, not even Babe Ruth in his heyday had drawn such mobs. Baseball was still the great pastime it had always been, and the crowd loved the feeling.

H.L. MENCKEN would have enjoyed No Big Deal: certainly in the strangled locutions of Fidrych he would have had dozens of entries for his Dictionary of the American Language. Tom Clark spent five days interviewing Fidrych and the product is this engaging, somewhat sophomoric account of the player's short career. Clark organized the narrative with some witty captions, which are an incongruously deadpan contrast to Fidrych's fractured lingo.

Fidrych's account begins with his sandlot days in Northboro, Mass., and then relates his quick rise through the minors into major league notoriety. Only die-hard baseball enthusiasts will appreciate this prolonged session of baseball gossip. In fact, such fans will not only appreciate it, they will relish it. The tales of Stubby Overmire, John "The Grod" Grodzinski, the Appalachian League, clubhouse follies--after all, what could be more enthralling?

Fidrych's descriptions of minor league life are the most colorful passages in the dialogue. Traveling through America's rural heartland, he plays in such populous cities as Thetford Mines, W. Va., and Bristol, Tenn. This is old time baseball, where Fidrych says "the game is still played." He recounts the pleasurable squalor of the "Jim Dandy Trailer Park," remembering how they whiled away the listless backwater hours with beer and cards. In contrast, his entry into the big leagues is a step into national limelight. Within two months of his first professional start, he is the best pitcher in the American League and at the center of an out-pouring of fan mania. Suddenly the baseball is not as enjoyable as it once was. Aqua Velva asks him to do commercials; he is plagued by endless promotionals:

They made a big promotion about it, y'know? A thing about it. And that promotion fell. That's what I loved about it. It fell. It would have been great if they'd won. But it fell. That's what was great. That's what my victory was.

FOR THE PAST few years, the owners, the general managers and the sport's other philistines have seemed bent on sanitizing and refurbishing the image of the national pastime. They installed flashy vending stands, digital clocks, and electronic scoreboards. They initiated all types of commercial gimmickry. With these vain and deluded efforts, they have hoped to turn baseball into a business. But the fans, like Fidrych, know better.