Last year's baseball wunderkind, Detroit pitcher Mark Fidrych, gets a fine assist from poet and baseball nut Tom Clark who puts the Big Bird's ""disjunctive rambles"" into semi-coherent prose. Fidrych is a naif, an exuberant bubble-head who violates most of the rules of jockdom. Beginning with his insouciance about his own talents. ""I just played the game, I didn't pay much attention to it."" After he was signed by Detroit, he traveled the minor league circuit with gleeful ease and got better and better the higher he rose--from Class A to Triple A to a two-hitter in his first start for the Tigers. Was it talent? Brains? Hard work? Fidrych credits ""the winning atmosphere."" Voom! That's his favorite all-purpose word and it does seem to describe both the trajectory and velocity of his pitches and his career, if he lost it all tomorrow, Fidrych supposes he could always go back to messing with the innards of cars. Would the city of Detroit mount an insurrection if he were traded? Probably. But, like his huge and instant fame--""it's no big deal.