Stock became a regular with the 1916 Phillies, taking over third base from a slumping Bobby Byrne. Just 5’8″, he had little power, but ran well and rarely struck out. In 1919 he was traded to the Cardinals and became their sixth regular third basemen since 1913. He solidified a good infield, and ran off four straight .300 seasons. In 1920 he led the NL with 639 at-bats.
On the last day of the 1950 season, the Dodgers, one game out of first, blew a chance for the pennant when Brooklyn’s Cal Abrams was thrown out at the plate by Phillies outfielder Richie Ashburn in the ninth inning of a tie game. Stock was the third base coach who waved Abrams home. He was fired several days later and never again coached in the majors.