Complex sentence: He would be the coach of the Jazz for the next seven 1/2 years, before retiring from coaching during the 1987-1988 season, when he moved into the team's front office (and was replaced as coach by Jerry Sloan).
Split into simpler sentences: He would be the coach of the Jazz for the next seven 1/2 years. He retired from coaching during the 1987-1988 season, moved into the team's front office (and was replaced as coach by Jerry Sloan).