In the past, major sports leagues fought to keep legalized gambling as far away from their games as possible. But in the wake of a Supreme Court ruling, things are looking a little different. Sportsbook partnerships with NFL, MLB and NHL teams are becoming more commonplace. And players like Edmonton Oilers star Connor McDavid are now appearing on the airwaves as spokespeople for gambling companies.

A number of rules are in place for official betting markets. First, bets are settled based on the final result declared by governing bodies such as the NBA and NCAA. If the score is changed after this initial declaration, bets are void. For a game to be considered official, it must have at least five innings completed. If a game is abandoned and not restarted within 24 hours, any bets will be deemed void.

Second, player props require a specific scoring play to be in action. For example, a field goal would count as a points scored while a sack wouldn’t. Finally, a player must start in the game for head-to-head player bets to pay out. If a player is subbed out, bets will remain live but won’t be settled.

The rules differ between sports, but in general, anyone who works for a professional league can’t bet on their own team. In baseball, for instance, it’s against the rules to bet on a game that doesn’t involve your team. Those who do face fines, suspension and even a permanent ban from the game if MLB finds they’ve broken this rule.