# What Is a Bookie? Definition, Duties, and How They Make Money

> **Definition**
>
> A bookie, short for bookmaker, is an individual or organization that facilitates gambling by setting odds, accepting bets, and paying out winnings, primarily in the context of sports betting.

## What Is a Bookie?

"Bookie" is a slang term for "bookmaker." It's someone who facilitates gambling, most commonly on sporting events. A bookie [sets odds](https://www.investopedia.com/articles/investing/042115/betting-basics-fractional-decimal-american-moneyline-odds.asp), accepts and places bets, and pays out winnings on behalf of others.

The Supreme Court legalized sports betting in 2018, enabling bookmakers to operate legally.

### Key Takeaways

*   Bookies, or bookmakers, facilitate gambling on sports by setting odds, accepting bets, and paying winnings.
*   The U.S. Supreme Court's 2018 ruling allowed states to legalize sports betting, expanding opportunities for legal bookmaking.
*   Bookies earn money through a fee called the "vigorish" or "vig," typically around 10% of bets placed.
*   Bookmakers aim to balance their books by adjusting odds to ensure an equal number of bets on each outcome.
*   Legal sports betting in many states has led to record gambling revenues in the U.S., with $66.65 billion in 2023.

## How Bookies Operate and Make Money

Bookies don't usually make their money by placing bets themselves. They charge a transaction fee on their customers' bets known as the "vigorish" or "vig" for short. Bookies may also lend money to bettors. A bookie can be an individual or an organization.

The term "bookie "has been associated with illegal activity, but being a bookmaker has become a legitimate occupation with the expansion of sports betting. Bookmaking and placing bets through a bookmaker can still be unlawful, however. State governments largely determine the legality of types of gambling.

> **Important**
>
> The Supreme Court's 2018 ruling allowed states to legalize sports betting, enabling bookies to profit legally.

## The Evolution of Bookmaking and Sports Betting

Until recently, legal sports betting in the U.S. was confined to Nevada, with limited options in Delaware, Montana, and Oregon. A [black market](https://www.investopedia.com/articles/economics/12/mechanics-black-market.asp) developed for the rest of the country as a result. Illegal bookies offered betting options, with some tied to organized crime, while others worked independently for friends or colleagues.

Then, in 2018, the U.S. Supreme Court struck down the Professional and Amateur Sports Protection Act. The Act was a federal law that prevented states from deciding independently whether to allow sports betting. The ruling allowed states to choose whether to legalize sports betting nationwide.

Many states have moved to legalize sports betting since that ruling. This has prompted record gambling revenues throughout the country, with combined revenue from traditional gambling, sports betting, and iGaming amounting to $66.65 billion in 2023. This was a record for the third year in a row, with an increase of 10% from the previous year.  

### $63.8 billion

The amount the American Gaming Association estimated that [Americans illegally wagered on sports](https://www.investopedia.com/americans-sports-betting-losing-8768618) in 2021.

## How Bookies Set Betting Odds

One of the crucial ways in which bookies try to ensure that they win is by calculating the odds that they'll do so. They sometimes employ teams of statisticians, and they develop complex models. The terms "lines" (short for "[money lines](https://www.investopedia.com/money-line-bet-5217219)") and "[spreads](https://www.investopedia.com/cover-the-spread-5217306)" (as in "point spreads") are critical factors for bookies. These calculations are sometimes based on those developed by [casino actuaries](https://www.investopedia.com/articles/professionals/090513/day-life-actuary.asp) or those who deal with risk calculations.

They typically underscore which sports team the bookies believe will win a game or a match. The lines and spreads can be adjusted in the time leading up to the event based on various bets made in their books and fluctuations in Las Vegas casino bets. Other unexpected events might impact the odds, such as poor weather, player injuries, and doping scandals.

A bookie's goal is to balance the books by adjusting odds to even out bets on wins and losses. The bookie effectively earns just the vig if the book is balanced, but they take on an increased risk of losing money if there's a one-sided bet on a particular team or outcome.

> **Tip**
>
> Call the National Problem Gambling Helpline at 1-800-522-4700, or visit NCPGambling.org/Chat to chat with a helpline specialist if you or someone you know has a gambling problem.

## Is Being a Bookie Illegal in the U.S.?

No, not necessarily. The U.S. Supreme Court opened the door for sports betting throughout the country in 2018 if states decide in favor of it. Some 38 states have since moved to legalize sports betting, effectively ending the need for bookies to operate illegally in those states.

That isn’t to say that all bookmakers are law-abiding, however. Betting is still illegal in some states and some bookies may prefer to conduct business under the table to avoid facing obstacles and paying taxes.

## How Do Bookies Make Money?

Bookies make money by charging a fee on each bet they take, known as the "vigorish" or the "vig.” They pay out money when their customers win a bet. Their goal is understandably to make sure that incomings exceed outgoings. That's generally achieved by adjusting the odds so there’s an even amount of people betting on a win or loss.

## How Much Is a Bookie Fee?

The vig that bookies charge is usually in the region of 10% but it can go higher for high-profile bets such as the Super Bowl.

## The Bottom Line

Bookies are bookmakers, people who facilitate betting on events. The professional involves managing the balance of bets and understanding the complexities of evolving odds in real time. They also need an extensive knowledge of risk management and odds setting to ensure profitability and compliance with legal regulations.

The 2018 Supreme Court ruling opened a legal path for sports betting across the U.S., significantly increasing opportunities for sports bookies to operate lawfully.

> **Article Sources**
>
> 1.  Supreme Court of the United States. "[Murphy, Governor of New Jersey, et al. v. National Collegiate Athletic Assn. et al](https://www.supremecourt.gov/opinions/17pdf/16-476_dbfi.pdf)." Pages 30-31.
>     
> 2.  Meer, Eric. "[The Professional and Amateur Sports Protection Act (PASPA): A Bad Bet for the States](https://scholars.law.unlv.edu/cgi/viewcontent.cgi?article=1026;context=glj)." _UNLV Gaming Law Journal_, vol. 2, no. 2, 2011, pp. 281-309.
>     
> 3.  Kasper, Madeline and Ryan LeCloux. "[States Are Placing Bets on Sports Betting: Will it Pay Off?](https://docs.legis.wisconsin.gov/misc/lrb/wisconsin_policy_project/wisconsin_policy_project_2_7.pdf)" _Wisconsin Legislated Reference Bureau_, vol. 2, no. 7, June 2019, pp. 1.
>     
> 4.  American Gaming Association. "[Interactive Map: Sports Betting in the U.S](https://www.americangaming.org/research/state-gaming-map/)."
>     
> 5.  American Gaming Association. "[AGA Commercial Gaming Revenue Tracker (CY 2023)](https://www.americangaming.org/resources/aga-commercial-gaming-revenue-tracker/)." Pages 1-2.
>     
> 6.  American Gaming Association. "[Sizing the Illegal and Unregulated Gaming Markets in the U.S](https://www.americangaming.org/resources/sizing-the-illegal-and-unregulated-gaming-markets-in-the-u-s/)."
>     
> 7.  BossAction. "[How to Be a Bookie?](https://www.bossaction.com/how-to-be-a-bookie/)"