The Supreme Court’s ruling has opened the door for states to legalize sports betting, with most now offering online and mobile sportsbook apps. But deciding what to wager on can be tricky. With so many options out there, it’s important to understand the difference between official betting and unofficial wagering.

The term “official” refers to a wager that uses data provided by a sport’s governing body. This data is considered more reliable and accurate than non-official information, which can come from a variety of sources.

In recent years, the NBA and MLB have begun lobbying state lawmakers for the right to control the flow of official data in regulated US sports betting. The leagues’ pitch is often accompanied by the concept of a “integrity fee,” referring to a cut of the overall sports betting handle that they would like to collect.

However, the idea of mandates to use official data has been met with fierce resistance from the players’ unions in college and professional sports. Mandates push private operators into commercial deals with the leagues, and they give one party what amounts to a monopoly over data.

Illinois legalized sports betting in 2019, and it launched in March 2020. The state offers a range of online and mobile options, including DraftKings, FanDuel, BetMGM, PointsBet, and BetRivers. In addition, Illinois residents can visit physical sportsbooks at casinos and racetracks across the state. There are also a number of sportsbook apps available for those who prefer to wager on games from the comfort of their homes.