[caption id="attachment_2735" align="alignnone" width="300"] "The Clincher" 16-inch softballs signature ball.[/caption] When it comes to softballs, players have a variety of choices in performance, style, covering and size. The most important distinction between softballs is the compression rating, which is the force in pounds it would take to squeeze the ball a quarter of an inch. Each type of softball is also available in a range of COR values. "COR" stands for the coefficient of restitution, which measures the degree of bounce when a ball hits a hard surface. Balls with higher COR values have more bounce. The largest type of softball is the 16-inch Chicago style softball. This type of softball is also soft because players usually do not use gloves. Chicago softball developed in the 1930s as an affordable alternative to baseball. Since the ball did not travel as far when hit, players could set up games in small playgrounds and neighborhood fields.