Michael William Krzyzewski ( ; nicknamed "Coach K"; born February 13, 1947) is an American college basketball coach and former player. Since 1980, he has served as the head men's basketball coach at Duke University, having taken over the program from Bill Foster. At Duke, Krzyzewski has led the Blue Devils to five NCAA Championships, 12 Final Fours, 12 ACC regular season titles, and 13 ACC Tournament championships. Krzyzewski is also the coach of the United States men's national basketball team, whom he led to two gold medals at the 2008 Summer Olympics and 2012 Summer Olympics. He was the head coach of the American team that won the gold medals at the 2010 FIBA World Championship and the 2014 FIBA World Championship. He was also an assistant coach for the 1992 "Dream Team".