If any baseball player whose name appeared on a major league roster during the 1946-80 period is missing from this exhaustive census of rookies, only trivia buffs will know for sure; Walton's roll call even includes one-game wonder Eddie Gaedel, a midget signed by Bill Veeck, who walked on four straight pitches in a 1951 contest between the St. Louis Browns and the Detroit Tigers. Offering a year-by-year rundown on all post-WW II newcomers to the big time, Walton gives journeymen, novas, and late bloomers equal billing with superstars--so this is more a Who's He? than a Who's-Who. The class of '47, for example--remembered primarily for Jackie Robinson's color-line breakthrough--also includes Bobby Thomson, Ralph Branca, Larry Jansen, and Sam Mele, along with the failed phenom. More recently, 1975's Rookie-of-the-Year Fred Lynn shares the spotlight with Red Sox teammate Jim Rice, Dennis Eckersley, John (""The Count"") Montefusco, et al.; briefly on hand as well are several lesser lights. And among the conclusions which can be drawn from the evidence here: a player's first-year record is not an infallible indicator of future performance. The text's strength--chronological, list-like inclusiveness--is also something of a weakness, which the author has sought to offset by inserting capsule commentaries on expansion, free agency, attendance records, World Series results, and other mileposts in professional baseball's history. Jarring sportspeak also abounds--e.g., ""he showed the skill and power that branded him for stardom."" But such quibbles apart, Walton has produced a comprehensive and ready reference that neatly bridges baseball's generation gaps.