The man that some called the most influential man in sports over the last half century succumbed Friday, four months after suffering a heart attack.

McCormack, the founder of International Management Group is credited with the rise of modern day athletes as pitchmen for consumer products. His first client was Arnold Palmer, in a deal they reportedly consummated with a handshake. Arnold Palmer held the endorsement deal title for years until Michael Jordan’s rise to prominence.

Today, the company McCormack founded is now known simply as IMG the world over, and provides client representation and financial management, event marketing and television representation, and production and distribution of golf’s international expansion.

IMG clients include Tiger Woods, Andre Agassi and Wayne Gretzky, among many others.

He is survived by his wife Betsy Nagelson, four children and seven grandchildren. His three adult children are all executives with IMG.

>>> The sports world loses another legend, one that made others famous, while bringing professional athletes into the mainstream…