By the numbers and near-acclamation, the best manager in baseball today is Earl Sidney Weaver--whose Baltimore Orioles have won more than 60 percent of their games since he took over midway through the 1968 season. Only Joe McCarthy accumulated victories at a faster pace, and no one has been ejected from more major league contests (or lost as much time in suspensions). Though this anecdotal account doesn't tap the essential Earl, ex-Baltimore sportswriter Pluto offers a solidly researched, career-spanning report--from Earl's baseball-crazy boyhood in St. Louis (where his dry-cleaner dad had the Cardinals' uniform account) through the strike-abbreviated 1981 season when, for a change, the Orioles finished up the track. Between times, the ultracompetitive Weaver played as an infielder for a succession of St. Louis farm clubs; by 1956, at age 26, he still hadn't made it past Class A ball. That year, however, was a turning point: he was appointed interim manager of the Knoxville Smokies and began his rise as a field boss. In eleven full seasons of piloting minor league clubs, Weaver lost more than he won just once. Even more impressive, he released only one player who later made it to the majors. Whatever Weaver's secret is, charm can be ruled out. Pluto documents long-running feuds with standout players and long-time baiting of umpires. (To the men in blue, he's the Son of Sam.) Nor is Weaver a particularly imaginative strategist: ""Pitching and three-run homers; that's what wins,"" he says. On the subject of Weaver's gifts, Pluto can't touch Thomas Boswell (How Life Imitates the World Series, p. 171). And Weaver's own story of his life is scheduled to appear in June. But Pluto's conscientious effort does put the record on record.