During his 20-year career as a professional boxer, Sugar Ray Leonard won world titles in five weight classes, became the first in his sport to earn more than $100 million in prize money, and helped fuel fans’ interest in boxing following Muhammad Ali’s retirement. Today Leonard calls fights for the streaming sports service DAZN and raises money for pediatric diabetes research.
A version of this article appeared in the January–February 2020 issue of Harvard Business Review.