Ray Chapman

Raymond Johnson Chapman (January 15, 1891 – August 17, 1920) was an American baseball player. He spent his entire career as a shortstop for the Cleveland Indians.

Chapman was hit in the head by a pitch thrown by pitcher Carl Mays and died 12 hours later. He is the only player to die directly from an injury received during a major league game. His death led baseball to establish a rule requiring umpires to replace the ball whenever it becomes dirty. Chapman's death and sanitary concerns also led to the ban on spitballs after the 1920 season. Chapman's death was also one of the examples cited to justify the wearing of batting helmets. However, it took over 30 years to adopt the rule that required their use. Provided by Wikipedia