As a coach with the Giants from 1949 to 1955, he was a member of two National League championship clubs (, ) and was the third-base coach of the World Series (1954) title team. However, he performed multiple tasks for Durocher during those seven seasons. According to author Joshua Prager in his 2006 book "The Echoing Green", Franks played a critical role in the Giants' Bobby Thomson's famous pennant-winning home run in the 1951 NL tiebreaker playoffs—Baseball's Shot Heard Round The World. According to Prager, Franks was stationed in the Giants' center-field clubhouse at the Polo Grounds, their home field, stealing the opposing catcher's signs through a telescope and relaying them through second-string catcher Sal Yvars (positioned in the bullpen) to the Giants' coaches and hitters. When asked where he was when Thomson hit his home run, Franks said, in 1996, that he was "doing something for Durocher" at the time.