A designated hitter (abbreviated as DH) is a position in baseball. Designated hitters do not play defensive positions, and only bat. The designated hitter was controversially introduced by Major League Baseball's American League in 1973, and most leagues use the position now, the most notable exception being Major League Baseball's National League. In Major League Baseball the designated hitter bats in place of the pitcher. Under many amateur leagues, the DH can replace any player in the field, usually the weakest batter. To this day, many baseball purists feel that this dilutes the game and that pitchers should bat. Although American League teams are not required to assign a designated hitter, in practice, all do.