While baseball players vary in size and strength, one element on the field has remained the same size since 1872 -- the baseball, according to the University of Illinois. The size of a baseball used in professional play is highly regulated to create uniformity among baseball teams. No matter what stadium a player plays in, the ball should be roughly the same in diameter, weight and circumference.
Reasons for Sizing
Although a baseball is relatively small in weight and size, each element is an important factor in determining how far the ball can be hit. In the early days of baseball, before balls were required to be standardized, teams would use tightly wound balls that would go farther when hit to score more runs, according to Chemical & Engineering News. If a team was better on defense, the team might use softer balls that would not go as far. By making baseballs a uniform size, shape and weight, all teams would be on a more even playing field -- and would be kept from doctoring the baseball to their teams' advantage.
Major League Baseball Regulations
Major League Baseball requires baseballs to be between 9 and 9.25 inches in circumference, according to the MLB website. The baseball should feature an inner core of cork or rubber covered by horsehide or cowhide stitched with yarn. In terms of weight, baseballs must weigh between 5 and 5.25 oz.
Size Changes in History
While the sizing of the baseball has been regulated since the 1860s, the size does not equal that of the MLB baseball in 2010. In the 1860s, a baseball was required to be between 9.75 and 10 inches in diameter -- roughly 7.9 to 8.1 cm, according to The Physics Factbook. Today, a baseball is at least 0.50 an inch smaller, a change that was made in 1872. This change was made to make the baseball less "lively," meaning it would not go as far when hit, according to Alan M. Nathan of the University of Illinois Physics Department.
Uniformity Testing
Major League Baseball regularly tests the balls used for conformity to ensure they are properly sized. Tests include being shot from a cannon into a wall made of the same material used to make baseball bats, according to Chemical & Engineering News. The ball must then bounce back at a certain speed -- hard enough to fly through the air and score a home run. The balls also must be large enough and structured properly to avoid distortion when thrown at high speeds.
Member Comments