Ray Chapman 4

Really a 3.5, generally regarded as the best all-around shortstop in the A.L. at the time of his untimely death, which was caused by a pitch from notorious headhunter Carl Mays that hit him in the head: in all likelihood the ball to the head was unintentional, Mays had a weird, unpredictable, submarine delivery, though Mays of course had a bad reputation as well, so who can say? This led to the use of fresh, clean balls instead of using the same dirty scuffed up ones, it also led to a crackdown on trick pitches, balls that had been tampered with, and the like. Chapman was a slick fielder with a good bat and speed, capable of hitting over 300, as he did several times, who played from 1912-20. Might have went on to a Hall of Fame career. Who knows? He was replaced at short by Joe Sewell, a future HOF'er who helped Chapman's teammates cope with the tragedy, and his fine play substituting for the popular Chapman helped the team go on to win the 1920 Series in part as a tribute to the fallen hero. A great book about all of this is Mike Sowell's "The Pitch That Killed."