The American League Adopts the Designated Hitter Rule

On January 11, 1973, at a joint meeting of major league owners in Chicago, the American League voted 8-4 to adopt the designated hitter rule on a three-year trial basis. The rule allowed a tenth player to bat in place of the pitcher without removing the pitcher from the game. The National League declined to adopt it, creating a structural split between the two leagues that lasted nearly fifty years.

The idea was not new. Connie Mack had suggested something similar as early as 1906, and National League president John Heydler had formally proposed a designated hitter in 1928. Both efforts went nowhere. By the early 1970s, however, American League attendance and scoring had declined sharply, and owners wanted a way to generate more offense.

The rule took effect immediately. On Opening Day, April 6, 1973, Ron Blomberg of the New York Yankees became the first designated hitter in major league history. Facing Boston's Luis Tiant, Blomberg walked with the bases loaded in his first plate appearance. His bat from that at-bat is now in the Hall of Fame.

What was intended as a temporary experiment became permanent. The American League never rescinded the rule, and the designated hitter spread through college baseball, the minor leagues, and international play. The National League held out until 2022, when MLB adopted the universal designated hitter across both leagues.

The designated hitter extended careers for aging sluggers and created a specialized offensive role that did not exist before. Players like Edgar Martinez, Harold Baines, and David Ortiz built Hall of Fame cases primarily as designated hitters. The rule also eliminated a strategic layer of the game. Managers no longer had to weigh when to pinch-hit for pitchers in close games, removing double switches and late-inning decisions that had been part of the sport since the 1800s.