Major League Baseball is governed by the
Major League Constitution, an agreement that has undergone
several incarnations since 1920, with the most recent revisions
being made in 2001. Major League Baseball, under the direction
of its Commissioner, hires and maintains the sport's umpiring
crews, and negotiates marketing, labor, and television contracts.
The 'closed shop' aspect of MLB effectively prevents the yearly
promotion and demotion of teams into the Major League by virute
of their performance (as, for example, in the English football
league system, where the bottom three teams in the highest
league are demoted to a lower league, and the top three from
the second highest league move into the top league).
MLB also maintains a unique, controlling
relationship over the sport, including most aspects of minor
league baseball. This is due in large part to a 1922 U.S.
Supreme Court ruling which declared baseball is not considered
interstate commerce (and therefore not subject to federal
antitrust law), despite baseball's own references to itself
as an "industry" rather than a "sport."
