Forbes - LA Clippers' Steve Ballmer richest owner in pro sports

Ballmer, who was the CEO of Microsoft from 2000 to 2014, has a net worth estimated at $83 billion. Despite a drop of $13.5 billion due to Microsoft's stock valuation, Ballmer is also the eighth-richest person in the world according to the publication. He bought the Clippers in 2014 and has been the sports world's richest owner ever since.

While a basketball owner is on top, the top 10 richest owners list is dominated by NFL owners.

Rob Walton, who purchased the Denver Broncos in June for $4.65 billion, is No. 2 on the list. The Walmart heir is worth an estimated $56.7 billion.

"The Broncos are the one sport franchise we would have considered buying,'' Walton said at the time. " ... We got in the middle of [the bidding] first thing. ... Terrific team, terrific fan base.''

Buying an NFL franchise seems like a good investment. Six of the world's 10 most valuable franchises, according to Forbes, are pro football teams, and their valuations have increased 1,500% on average since 1998, according to the publication's calculations.

Dan Gilbert, the owner of the Cleveland Cavaliers, fell from No. 2 to No. 6. His move down was due to Rocket Mortgage, the company he founded and owns, losing half its stock valuation.

Of Forbes' 400 richest people in the world, 50 sports team owners are on the list.