Political pundit Will, as readers of his column are aware, is a baseball buff whose principal claim to fame has been an unrequited passion for the Chicago Cubs. Here, he essays a sort of thinking-man's guide to the national pastime--one that, for all its occasional pleasures, is gratingly pretentious. Ostensibly, Will focuses on four real pros: Tony LaRussa (manager, Oakland Athletics); Orel Hershiser (pitcher, Los Angeles Dodgers); Tony Gwynn (outfielder, San Diego Padres); and Cai Ripken, Jr. (shortstop, Baltimore Orioles). The nominal subjects of his profiles, however, serve mainly as departure points for wide-ranging inquiries into base-running, defense, hitting, pitching, stealing (signs as well as bases), and other of baseball's essential skills. At his best, Will is an informed, frequently astute, student of the diamond. He appreciates, for instance, that any given matchup can surprise because the players ""are not robots."" In addition, the author persuasively rates today's ""physically more impressive"" stars above their storied counterparts of yesteryear. As often as not, however, he parades his knowledge, introducing extraneous facts, minutiae, and statistics that dazzle rather than illuminate. Without explanation or any mention of Latin countries, for example, Will offers a rundown on the changing list of states that produce the greatest numbers of major-leaguers. Included as well (without further comment) are data on losing streaks and consecutive winning seasons for franchises in all sports. Nor does Will shrink from pedantspeak (e.g., arguing at one point that ""baseball exemplifies a tension in the American mind, a constant pull between our atomistic individualism and our yearning for community""). He concludes with an odd harangue on the sorry State of the Union vis-Ã¡-vis the putatively healthy condition of the game he also loves. The scouting report: Good hit, no field; can't go to his left.