On September 13, 2012, all 29 league ownership groups (with the Phoenix Coyotes collectively owned by the NHL) authorized commissioner Gary Bettman to lock out the National Hockey League Players' Association (NHLPA) upon the expiration of the NHL collective bargaining agreement (CBA) on September 15. The action marked the fifth labour dispute in twenty years for the league, following a 1992 strike, lockouts in 1994–95 and 2004–05, as well as a referees lockout in 1993; this is more than any of the other major professional sports leagues in the United States and Canada during this period. In preparation for the lockout, NHL teams assigned all of their eligible players to their American Hockey League farm clubs.
