A breezy, against-the-grain appreciation of pro ball from an enthusiast who knows the score in the front office as well as on the field. Best known for the leading role he played (as general manager) in making a contender of the hapless Pittsburgh Pirates a couple of seasons back, Thrift is a well-traveled baseball executive and a genuine student of the game. A left-handed pitcher who never made it out of the minors, the author has (with time out to build a successful real-estate business) been in or around the major leagues since 1949. Employed at various times by the larger-than-life likes of Charles O. Finley and George M. Steinbrenner (whom he quit last August), Thrift spent a formative three-year period as founding director of the baseball academy established to polish diamond roughs for Ewing Kauffman's Kansas City Royals. In providing an episodic rundown on his own career, he sheds light on the many innovations he and his computer-using allies have made in workaday fundamentals in a tradition-minded sport. Cases in point range from the time-measured lead and four-seam fastball through conditioning/nutrition programs keyed to players' positions. Among other examples of how an investive approach can pay off, the author cites Kevin Mitchell; having discovered that the slugging outfielder's buttock and hip muscles were overly tight, a consultant put him on a regimen that helped get the San Francisco Giants into the 1989 World Series. Nor is Thrift overly impressed by strategy, ""probably the most overrated part of the game."" Of appreciably greater value to baseball, he insists, are knowledgeable, attentive analysts, instructors, scouts, and teachers. Trade secrets from a real pro with the wit to question conventional wisdom; a fine treat for baseball fans whether or not they have to while away a silent spring.