Rule 1.09: “The ball shall be a sphere formed by yarn wound around a small core of cork, rubber or similar material, covered with two strips of white horsehide or cowhide, tightly stitched together. It shall weigh not less than five nor more than 5½ ounces avoirdupois and measure not less than nine nor more than 9¼ inches in circumference.” What precisely is this rule referring to? Via the official rules of professional baseball, the required parameters of the baseball itself. The required weight and size have not changed since these rules were enacted in 1872, but the materials used for certain parts of the baseball have changed. Before 1872, the ball weighed in between 3-6 ounces, was as small as a golf ball or as large as a softball, had a string-wrapped rubber core and didn’t go terribly far when hit. The change of the core to cork, beginning in the 1910 World Series, made the ball much more “livelier.” The official end to the dead ball era came in 1919 when Babe Ruth smacked a then record 29 home runs. In 1931, small changes “deadened” the ball slightly, in response to pitcher demand. The cork core was wrapped in a thin layer of rubber and the stitching on the seams was raised so the pitcher could get a better grip on the ball. The last significant change came in 1974, when horsehide was permanently replaced by less costly cowhide for the outer covering.
Photo: Stephen Lang