WHO WAS STUFFY McINNIS? A native of Gloucester, Mass. and a high school baseball standout at 15, Jack McInnis found himself at age 16 in 1907 as the star player and youngest member of a long-forgotten but once wildly popular Beverly semi-pro team that played its home games at a long-forgotten ballpark. Enthusiastic fans who shouted ÒThatÕs the stuff, Kid!Ó whenever he made an outstanding play soon gave Stuffy his lifelong nickname. While still just a kid of 18, Stuffy became the youngest player in the American League when he earned a spot on the roster of MackÕs Philadelphia Athletics.