Photographer: Shaun Botterill/Getty Images If you want to make money from professional sports, trying to win a competition is a real punt. Far better to own the competition itself. Even better, own several competitions. The surge in online streaming has prompted private equity firms to scramble for ways to get into the content game. Many seem to have landed on sport as a good opportunity: a quarter of the 20 teams in English soccer’s Premier League now have an owner in private equity. If you...