The biggest example of a value sports league aligning themselves with the best athletes in the world is the rumored $200 million contract with the Saudi-backed LIV Golf tour.

David Carter is a professor of sports business at USC and is the founder of the consulting firm Sports Business Group. They used to be just employees.

One of the most exclusive clubs in all of sports, those athletes who have earned more than $1 billion in their careers, are now joined by Phil Mickelson, who has earned more than $1 billion in his career.

The seven athletes on the list, which includes soccer, tennis and basketball players as well as golfers, have become global icons, leading to more lucrative opportunities outside their fields of play.

Tiger Woods made less than 10% of his career haul from golf winnings, with the rest coming from massive endorsement deals he has maintained over the course of his career.

Both Woods and James have made a lot of money from smart investments and are billionaires. They are the only two people in this group who have a billion-dollar income. Earnings are recorded before taxes and other costs.

Modern media has enabled the existence of athlete billionaires. As the celebrity of top athletes increases, so does the size of their endorsements.

Carter says that none of the guys are going to be billionaires if they don't have a global presence. The fact that most businesses these guys are involved in have a global attached to it is new in the last generation.

In recent years, record-breaking sports contracts seem to be surpassed before the ink on the previous record holder is dry. Expect more athletes to join the elite.

All-Time Earnings Leaders

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BenJared/PGA TOUR.

Tiger Woods $1.72 bil

Golf

At his peak, the 46-year-old Woods was the most prolific athlete endorser in history, raking in over $100 million off the course per year.

cristiano-ronaldo-by-Rui-Vieira-AP

There is a person named Rui Vieira.

Cristiano Ronaldo $1.24 bil

Soccer

The world's all-time goal- scoring leader is able to command high rates from sponsors because of his large following on social media. He's an investor in Tatel restaurants and a forthcoming soccer community app Zuju GP, and still commands premium wages for Manchester United.

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There is a photo of Jayne Kadin.

LeBron James $1.16 bil

Basketball

In addition to his lifetime contract with Nike and a $41.5 million contract with the Los Angeles Lakers, the 37 year old hoops legend sold a significant minority stake in his production company in October at a valuation of $725 million. He has taken equity stakes in several of the companies he has endorsed, all of which add up to a billion dollars in net worth.

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The photo was taken by marco Machado.

Lionel Messi $1.15 bil

Soccer

Despite a pay cut when he moved to Paris Saint-Germain, the Argentine forward was the highest paid athlete in the world over the last year. He added a $20 million deal with fan engagement app Socios when to go with long-term deals with brands.

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A person named Kirsty Wigglesworth.

Roger Federer $1.09 bil

Tennis

In the last year, the 40-year-old Swiss maestro earned more money than any other athlete in the world, despite not playing in a tournament since Wimbledon last July. He invests in shoe brand On and is a top pitchman for several brands.

Floyd-Mayweather-by-Isaac-Brekken-AP

Isiah Brekken/ AP

Floyd Mayweather $1.08 bill

Boxing

He made the most money in the history of sports when he made the most money from his fight with the Irishman. He received a cut of the pay-per-view, gate, sponsorship, merchandise, and international TV deals for each of the four most profitable fights in boxing history, as a result of his decision to run his own promotion company.