Clemens debuted in the major leagues in 1984 with the Boston Red Sox, whose pitching staff he anchored for 12 years. In 1986, he won the American League (AL) Cy Young Award, the AL Most Valuable Player (MVP) Award, and the All-Star Game MVP Award, and he struck out an MLB-record 20 batters in a single game (Clemens repeated the 20-strikeout feat 10 years later). After the 1996 season, Clemens left Boston via free agency and joined the Toronto Blue Jays. In each of his two seasons with Toronto, Clemens won a Cy Young Award, as well as the pitching triple crown by leading the league in wins, ERA, and strikeouts. Prior to the 1999 season, Clemens was traded to the New York Yankees where he won his two World Series titles. In 2001, Clemens became the first pitcher in major league history to start a season with a win-loss record of 20–1. In 2003, he reached his 300th win and 4,000th strikeout in the same game. Clemens left for the Houston Astros in 2004, where he spent three seasons and won his seventh Cy Young Award. He rejoined the Yankees in 2007 for one last season before retiring. He is the only pitcher in major league history to record over 350 wins and strike out over 4,500 batters.