William Stanley Mazeroski, nicknamed "Maz" and "the Glove", is an American former second baseman in Major League Baseball (MLB) who played his entire career for the Pittsburgh Pirates from 1956 to 1972. A seven-time All-Star known during his career primarily for his spectacular defensive play, he has come to be better known for perhaps the most memorable home run in baseball history, a dramatic ninth-inning drive in Game 7 of the 1960 World Series that beat the favored New York Yankees. It was the first time that the major league season ended with a home run, and remains the only walk-off home run to clinch a World Series championship in Game 7. ESPN ranked the World Series winner at the top of its list of the 100 Greatest Home Runs of All Time, while Sports Illustrated had it eighth in its compilation of the 100 Greatest Moments in Sports History. Mazeroski received the Babe Ruth Award for his play in the Series, during which he batted .320.

In baseball and softball, second baseman, abbreviated 2B, is a fielding position in the infield, between second and first base. The second baseman often possesses quick hands and feet, needs the ability to get rid of the ball quickly, and must be able to make the pivot on a double play. In addition, second basemen are usually right-handed; only four left-handed throwing players have ever played second base in Major League Baseball since 1950. In the numbering system used to record defensive plays, the second baseman is assigned the number 4.