Clark, a poet smitten by baseball, pegs the redoubtable Charley F. as a mean little s.o.b. In fact the man who introduced to the national pastime such novelties as a ""Miss US. bat girl,"" the Alert Orange Baseball, ""hot pants day"" and other attendance seams, comes across as a vulgar cheapskate, a real capitalist pig. True, Finley bought the tattered Kansas City Athletics and transformed them into the blue-chip, mustachioed Oakland A's--thrice World Series champs. Apparently they were a club that thrived on discord, insults, fist fights, and head-rolling by the monomaniacal owner--who also performed, when he felt like it, as manager, PR man, talent scout, and Santa Claus. Charley, a novelty among baseball's generally somnolent owners, is the true fascination of this ball club--despite Clark's penchant for a play-by-play description of the A's climb to the top. He sets it down in the present tense, presumably for immediacy: Reggie Jackson's tears and hold-outs, Vida Blue's zingy fastballs (Charley wanted to rename him True Blue), Catfish's quiet, well-executed defection to the Yanks. Charley raised them from the ashes and presumably will grind them into the dirt again, though this year's team could hardly be called meek. It's too soon for an Oakland Boys of Summer, but Clark has plenty of wit and sarcasm to unloose on Finley's ""preternatural talent for antagonizing people."" Enough to entice baseball addicts and maybe even some on the sidelines.