John Heydler resigns as NL president due to poor health. During his 16 years he hired the Elias brothers to maintain as official keeper of playing statistics (1919). He was influential in the election of Kenesaw Mountain Landis (1921) and the establishment of the Hall of Fame. In 1929 Heydler proposed permitting a tenth player to bat in place of the pitcher – a rule which came about with the creation of the designated hitter in 1973.
- Designated hitter, Elias Sports Bureau, John Heydler, Kenesaw Landis, National League President