What Is a Sportsbook?

A sportsbook is a gambling establishment that accepts wagers on a variety of sporting events. The odds on these bets, which are based on probability, are adjusted to draw action from both sides of a wager. The goal of a sportsbook is to earn money from bettors while keeping the house edge as small as possible.

A legal sportsbook must be licensed by a state in which it operates. It can either be an established business with a physical location or an online operator that offers a virtual betting experience. DraftKings became the first operator to launch a licensed online sportsbook in the United States after the Supreme Court overturned the federal wagering ban PASPA. Other operators have since followed suit, and players in most states now have access to industry leaders that offer a wide range of bets and welcome bonus offers.

Bettors can make a variety of bets at a sportsbook, from individual team and player props to exotic bets like parlays. In-game wagering is another popular option, allowing bettors to place multiple bets during the event itself. Some sportsbooks also offer your money back when a bet pushes against the spread. It’s important to know your sportsbooks’ rules when placing bets, so you can keep track of winning and losing bets.

The best U.S.-based online sportsbooks are operated by well-known brands with good reputations for customer service. FanDuel, for example, is a household name thanks to its DFS success. Caesars Sportsbook, meanwhile, has a solid reputation for offering odds boosts, in-game betting, and a generous welcome bonus that includes free bets and access to their loyalty program. The best sportsbooks feature a broad selection of markets, including major leagues from the NFL, NHL and NBA as well as international and niche sports such as Australian Rules and water polo. Some sites even offer betting exchanges where bettors can take one another up or down on odds.