Plank, a graduate of Gettysburg College, made his Major League debut on May 13, 1901 for the Philadelphia Athletics, a team he would play for until 1914. Over this time, he would be one of the most consistent pitchers in the game, winning over 20 games seven times and contributing to two World Series championships, one in 1911, the other in 1913. He was known as a finesse pitcher with a good sidearm sweeping curveball. He was also known for his long pauses on the mound, which some claimed lengthened the duration of the games in which he pitched.
In 1915, Plank played for the St. Louis Terriers and won 21 games, the eighth and final time he would reach the 20-win plateau. In 1916 and 1917 he played for the St. Louis Browns. He retired after the 1917 season.
Over his career, Plank amassed a 326-194 record, a 2.35 ERA and 2246 strikeouts.
Plank was inducted into the Baseball Hall of Fame in 1946.