Sports betting: how the business works
A sportsbook sells prices on sporting outcomes. It earns money in two ways: by building a margin into every market, and by managing its exposure so that results, on average, fall in its favour. Unlike a casino, a sportsbook can lose on a weekend of results, which makes pricing and risk management the heart of the business.
Margin: the price of the product
Bookmakers set odds so that the probabilities they imply add up to more than one. In a two-way market at 1.91 on both sides, the implied probabilities add up to 4.7% more than a fair book: that excess is the overround. If stakes arrive in proportion, the book keeps 4.5% of everything staked whatever the result. A typical football match-result market at 2.40, 3.30 and 3.10 carries an overround of 4.2%. The margin calculator works this out for any market.
Hold: what the book actually keeps
Hold is gross gaming revenue divided by stakes. It depends on the margin, on the product mix and on results. Accumulators and bet builders carry much higher margins than single bets, because the margin of each leg compounds, which is why operators promote them. On a handle of 10,000,000 and a hold of 7.5%, gross gaming revenue is 750,000; the GGR and hold calculator takes it on to net revenue after bonuses and tax.
Trading and risk
- Most operators license odds and risk services from specialist suppliers and adjust them with their own traders.
- In-play betting now makes up a large share of turnover in many markets and depends on fast, official data feeds.
- Sharp customers, who consistently beat the closing price, are often limited or priced differently.
- Integrity monitoring services watch for suspicious betting patterns and alert sports bodies.
Regulation at a glance
Sports betting is the most widely licensed form of online gambling. Even monopoly markets often offer it through a state operator, and several federations, such as the United States and Canada, license it state by state.
Of the markets we track. Open the full regulation tracker
What is changing
- New licensed markets keep opening, most recently in the United States, Canada and Brazil.
- Betting taxes are rising in several markets, such as the United Kingdom's new rate for remote betting from April 2027.
- Advertising and sponsorship limits are tightening, from outright bans to watershed rules.
Related: esports betting, horse racing and pool betting, prediction markets and the odds converter.
Suppliers in this field
Sports data and integrity
- Sportradarsportradar.com
Sports data, odds and integrity services.
- Genius Sportsgeniussports.com
Official sports data, betting technology and integrity services.
- Stats Performstatsperform.com
Sports data and analytics, including betting feeds.
- Swish Analyticsswishanalytics.com
Sports betting analytics, odds and player props.
- SISsis.tv
Live betting content: racing and numbers games.
- OpticOddsopticodds.com
Real-time odds data feeds.
- Oddin.ggoddin.gg
Esports odds feed and sportsbook.
- GRIDgrid.gg
Official esports data platform.
- SportsDataIOsportsdata.io
Sports data feeds and APIs.
Virtual sports
- Inspired Entertainmentinspiredentertainment.com
Virtual sports, gaming machines and online slots.
- Kiron Interactivekironinteractive.com
Virtual sports and numbers games.
- Golden Racegoldenrace.com
Virtual sports and betting games.
Editorial listings, not endorsements. Full supplier directory
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