Sports betting is the activity of predicting sports results and placing a wager on the outcome. Sports bettors place their wagers either legally, through a bookmaker/sportsbook, or illegally through privately run enterprises referred to as “bookies”. The term “book” is a reference to the books used by wage brokers to track wagers, payouts, and debts. Many legal sportsbooks are found online, operated over the Internet from jurisdictions separate from the clients they serve, usually to get around various gambling laws (such as the Unlawful Internet Gambling Enforcement Act of 2006 in the United States) in select markets, such as Las Vegas, or on gambling cruises through self-serve kiosks.
There are different types of legalized sports betting now such as game betting, parlays props and future bets. They take bets “up-front”, meaning the bettor must pay the sportsbook before placing the bet. Due to the nature of their business, illegal bookies can operate anywhere but only require money from losing bettors and do not require the wagered money up front, creating the possibility of debt to the bookie from the bettor. This creates a number of other criminal elements, thus furthering their illegality.(來源)
The bookmaker functions as a market maker for sports wagers, most of which have a binary outcome: a team either wins or loses. The bookmaker accepts both wagers, and maintains a spread (the vigorish) which will ensure a profit regardless of the outcome of the wager. The Federal Wire Act of 1961 was an attempt by the US government to prevent illegal bookmaking.
However, this Act does not apply to other types of online gambling. The Supreme Court has not ruled on the meaning of the Federal Wire Act as it pertains to online gambling. Bookmakers usually hold an 11–10 advantage over their customers—for small wagers it is closer to a 6–5 advantage—so the bookmaker will most likely survive over the long term. Successful bookmakers must be able to withstand a large short term loss. (Boyd, 1981) (來源)
