John (Jack) Albert Pfiester (May 24, 1878 in Cincinnati, Ohio – September 3, 1953), is a former professional baseball player who pitched in the Major Leagues from 1903 to 1911. Pfiester finished with a 1.51 ERA in 1906 (one of the best rookie seasons by any pitcher since), and a 1.15 ERA in 1907. His career ERA is 2.02, 3rd lowest among pitchers with 1,000+ innings thrown, and he had a .617 winning percentage. On September 23, 1908 against the New York Giants he pitched a complete game, allowing five hits, all with a dislocated tendon in his pitching forearm. He had to be assisted off the field a few times after throwing curve balls. And as soon as the game ended he went to Ohio to be treated, his tendon snapped back into place by Bonesetter Reese.