A sportsbook is a venue, whether it’s a website or brick-and-mortar building, that accepts bets on sporting events. They are often legally regulated and provide bettors with odds to make their decisions. However, there are many aspects of a sportsbook that punters should know before betting with one. Read on to learn everything you need to know about sportsbooks, including their history, whether they’re legal, how they make money, and more.

A key concept to understand is the “synthetic hold.” This is a calculated number that is created by taking the best line on each side of a market and calculating its win probability as if it were the total. The lower this number, the lower the sportsbook’s edge and the greater your chances of profiting from a wager.

Several online sportsbooks offer this service and it’s something punters should look for when comparing sites. This way, you can be sure you’re getting the most competitive odds on any given game or prop.

In the past, same-game parlays were rarely offered at sportsbooks, but they’re now commonplace and can have huge payouts. However, they’re not without their fine print as they are typically void if any of the legs lose. Thankfully, DraftKings and some other sportsbooks are different and they only void the entire parlay if one of the legs loses. This has led to a much higher payout potential on same-game parlays and makes the risk/reward more attractive.