Played all 12 of his NHL seasons for the Boston Bruins. In the middle of a Madison Square Garden brawl in 1979, he got into an altercation, drawing a six-game suspension after hitting a fan with the fan's shoe. During his career he was Boston's National Hockey League Players' Association representative. Took the Boston Bruins to the Stanley Cup finals in 1990, his first season as head coach. Served as both a head coach and general manager during his tenure with the New York Islanders. A controversial announcer---sometimes called "Mad Mike"---he came under fire for his comments on NBC about the Russian hockey team during the 2010 Winter Olympics.