Bill Walsh, who led the San Francisco 49ers to three Super Bowl championships and six NFC West division titles in his 10 years as head coach, has died at the age of 75.  Walsh died early Monday following a long battle with leukemia, according to Stanford University, where he served as coach and athletic director.

Walsh didn’t become an NFL head coach until 47, and he spent just 10 seasons on the San Francisco sideline. But he left an indelible mark on the United States’ most popular sport, building the once-woebegone 49ers into the most successful team of the 1980s with his innovative offensive strategies and teaching techniques.

Walsh went 102-63-1 with the 49ers, winning 10 of his 14 postseason games along with six division titles. He was named the NFL’s coach of the year in 1981 and 1984.

R.I.P. Coach Walsh