Miami Dolphins owner Stephen Ross is in advanced talks to sell 13% of his sports portfolio, according to Bloomberg News. The deal reportedly includes a portion of the NFL’s Miami Dolphins, Hard Rock Stadium, the Formula 1 Miami Grand Prix, and a piece of Ross’ 50% ownership stake in the annual Miami Open tennis tournament.

This deal has not been finalized, and it may not end up being finalized, as Ross previously had a framework agreement with billionaire Ken Griffin to buy a stake in the Dolphins, only for it to fall apart after Griffin requested a path to majority control.

However, if the agreement does get finalized, this is a huge deal because 1) it values the assets at $8.1 billion, and 2) Ares Management would be purchasing a 10% stake, with billionaire Brooklyn Nets owner Joe Tsai acquiring the other 3% equity position.

This is an important detail, as it would make Ares Management the first private equity firm to buy a stake in an NFL team. As a reminder, NFL owners voted to change the league’s rules earlier this summer, pre-approving a handful of private equity firms to acquire small, passive equity stakes in up to six NFL teams each.

This rule change was seen as a win-win for everyone — NFL owners get a little bit of liquidity, team valuations continue to rise because of increased demand and private equity managers get to clip lucrative management fees on an illiquid asset with a long track record of price appreciation that is uncorrelated to the broader equity market.

The more interesting part to me is what this means for other sports owners.

Stephen Ross has rewritten the playbook on compounding capital via professional sports in the 21st century. Ross made his money in real estate, so it should be no surprise that his $1 billion purchase of the Dolphins included the team’s stadium, too.

This may seem like the norm, but it’s actually incredibly uncommon in the NFL. Only five NFL teams own the stadium they play in, with most teams, like the Cowboys, Bears, and Packers, paying millions of dollars in annual rent because their stadium was partially funded (and therefore owned) by the local government and its taxpayers…