The manager's responsibilities normally are limited to in-game decisions, with off-field roster management and personnel decisions falling to the team's general manager. The term "manager" used without qualification almost always refers to the field manager (essentially equivalent to the head coach in other North American professional sports leagues), while the general manager is often called the GM. This usage dates back to the early days of professional baseball when it was common practice for teams to have just one "manager" on their staff, and where GM duties were performed either by the field manager or (more commonly) by the owner of the team. Some owners (most famously, Connie Mack of the Philadelphia Athletics) carried out both GM and field managerial duties themselves.