Dennis Dale McLain is an American former professional baseball player. He played for ten seasons in Major League Baseball as a right-handed pitcher, most prominently as a member of the Detroit Tigers. In 1968, McLain became the last Major League Baseball pitcher to win 30 or more games during a season — a feat accomplished by only 11 players in the 20th century, with the most recent 34 years earlier.

Major League Baseball (MLB) is a professional baseball league and the highest level of organized baseball in the United States and Canada. One of the big four major leagues, MLB comprises 30 teams, divided equally between the National League (NL) and the American League (AL), with 29 in the United States and 1 in Canada. Formed in 1876 and 1901, respectively, the NL and AL cemented their cooperation with the National Agreement in 1903, making MLB the oldest major professional sports league in the world. They remained legally separate entities until 2000, when they merged into a single organization led by the Commissioner of Baseball. MLB is headquartered in Midtown Manhattan.