Joe Kocur was a hockey enforcer for the Detroit Red Wings and the New York Rangers, back in the heyday of hockey's tough guys. Kocur talks to host Ira Glass about how a good enforcer keeps other players in line. If you want to read more stories about Joe Kocur's life as a hockey enforcer, it's all in a new book called The Bruise Brothers, about Kocur and his teammate (and fellow enforcer) Bob Probert. The book is only available at immortalinvestments.com. (5 minutes)