The American Hockey League (AHL), sometimes referred to as "The A", is the primary developmental professional league for players aspiring to enter the NHL. It comprises 31 teams from the United States and Canada. It is run as a "farm league" to the NHL, with the vast majority of AHL players under contract to an NHL team. The ECHL (called the East Coast Hockey League before the 2003–04 season) is a mid-level minor league in the United States with a few players under contract to NHL or AHL teams.