Mark McGwire (born October 1, 1963), nicknamed "Big Mac", is a former Major League Baseball player who played his major league career with the Oakland Athletics and the St. Louis Cardinals. He replaced Hal McRae as the hitting coach for the St. Louis Cardinals for 2010.
For his career, McGwire averaged a home run once every 10.61 at bats, the lowest at bats per home run ratio in baseball history (Babe Ruth is second at 11.80). In 1987, he broke the single-season home run record for rookies, with 49. In 1998, McGwire and Sammy Sosa achieved national fame for their home run-hitting prowess in pursuit of Roger Maris' single season home run record; McGwire broke the record and hit 70 home runs that year. Barry Bonds, who allegedly also took steroids, now holds the record, after hitting 73 home runs during the 2001 season. In 2010, McGwire publicly admitted having used performance-enhancing drugs throughout his career.