ARI SHAPIRO: The NFL and other leagues have fought sports betting in the past. But in 2018, the Supreme Court threw open the door to legal sports gambling. That changed everything. So we talked to ESPN’s David Purdum about how sports betting has changed since the Supreme Court ruling.

The NFL had feared that legal sports betting would lead to more attempts at fixing games for betting purposes. But after the ruling, it’s embraced it in a big way, partnering with betting sites and even having its own betting app. What’s behind that shift?

In baseball, players, umpires and club and league officials are banned from seeking, accepting or offering a bribe to fix a game. The prohibition also applies to those who have a “duty of performance” at the game, such as pitchers and catchers. The penalties for breaking the rules include being permanently banned from Major League Baseball, although this has happened only a few times in history.

The sportsbook industry uses a system called totalizators to display odds. These change in real time based on the share of the total exchange each of the possible outcomes have received, taking into account the bookmakers’ return rate. This is a form of dynamic pricing, similar to the parimutuel wagering used in horse racing and dog races. In this type of bet, the higher the volume on a particular outcome, the lower the odds are. This is a form of price-control and is designed to give the house a fair advantage over bettors.