On April 20, 1941, the Brooklyn Dodgers become the first major league team to wear protective headgear. Each player’s cap features a special plastic lining designed to fend off the effects of “beanballs.” It is a cautious response to the numerous beanball wars of 1940 that hospitalized Joe Medwick and Billy Jurges, among others. The liners in the caps are thin enough to be hardly noticeable, but most major league players disdain the protection.