Bill Russell, Celtics Assumed helm of nine-time champions before 1966-67 season; won two titles in three-year stint as player-coach.
Phil Bengtson, Packers Winning wasn't everything for Lombardi's 1968 successor, who went 20-21-1 in three seasons.
Claude Ruel, Canadiens Replaced eight-time Stanley Cup winner Toe Blake after 1968 season; earned another Cup in '69 but missed playoffs in '70.
Gene Bartow, UCLA basketball John Wooden's replacement in 1975 went 52-9 over two years but failed to win national championship.
George Seifert, 49ers Took over three-time champs in 1989; won Super Bowl in first season and again five years later.