King Kelly, American baseball player and manager (d. 1894)

Michael Joseph "King" Kelly (December 31, 1857 – November 8, 1894), also commonly known as "$10,000 Kelly", was an American outfielder, catcher, and manager in various professional American baseball leagues including the National League, International Association, Players' League, and the American Association. He spent the majority of his 16-season playing career with the Chicago White Stockings and the Boston Beaneaters. Kelly was a player-manager three times in his career – in 1887 for the Beaneaters, in 1890 leading the Boston Reds to the pennant in the only season of the Players' League's existence, and in 1891 for the Cincinnati Kelly's Killers – before his retirement in 1893. He is also often credited with helping to popularize various strategies as a player such as the hit and run, the hook slide, and the catcher's practice of backing up first base.In only the second vote since its creation in 1939, the Old Timers Committee (now the Veterans Committee) elected Kelly to the Baseball Hall of Fame in 1945.

In concluding where to truly give Kelly credit as an innovator, a 2004 book devoted to 19th-century rule bending in baseball—and which came close to exhaustively accounting for all contemporary reporting on various subjects—placed stress on the following: "Kelly's hook slide does sound special, and players probably tried to copy it. Also, he seems to have been the first big leaguer to successfully cut a base (when the usually lone umpire wasn't looking), at least according to the newspaper record." And, "Kelly could have been the first to foul off lots of pitches on purpose. Doing so was a top trick of some Baltimore players of the 1890s. At the turn of the century, that trick was defused when all foul balls began counting as strikes."Kelly's autobiography Play Ball: Stories of the Ball Field was published while he was with the Beaneaters in 1888, the first autobiography by a baseball player; it was ghostwritten by Boston baseball writer John J. "Jack" Drohan. Kelly also became a vaudeville performer during his playing career, first performing in Boston where he would recite the now-famous baseball poem "Casey at the Bat", sometimes butchering it. Kelly's baserunning innovations are also the subject of the hit 1889 song entitled "Slide, Kelly, Slide" and a 1927 comedy film of the same name.