1972 December

0th  The major leagues adopt the save as an official statistic. A pitcher shall be credited with a save if, when entering a game as a reliever, he finds the tying or winning run on base or at the plate, and he preserves the lead. Or he pitches 3 effective innings and preserves the lead.

The AL votes unanimously to adopt the designated-hitter rule for a 3-year experimental basis. The DH will replace the pitcher in the lineup unless otherwise noted before the start of the game. In the December 1975 meeting the AL will vote to permanently adopt the DH. The NL declines to go along with the AL.

31st  A plane carrying Roberto Clemente to Nicaragua on a mercy mission for earthquake victims crashes into the Atlantic Ocean. Clemente, who batted .317 in 18 seasons with the Pirates, is presumed dead at age 38.