In short: A sportsbook is a business that takes bets on sporting events at published odds and pays out on winning bets. Online, it is software that combines a sports data and odds feed, a betting interface, risk management, a player wallet and bet settlement. The sportsbook earns from the margin built into its odds, not from predicting results.
Last reviewed: 25 October 2026.
If you run or plan an online casino, sports betting is the most common second product players ask for. It also works very differently from a casino. A slot has a fixed mathematical return that never changes; a sportsbook prices real-world events that change by the second and can only be settled once the result is known. This guide explains what a sportsbook is, how a bet moves through one, and what an operator needs in place before taking the first wager. If you already know the basics and want the launch plan, read our guide on how to start a sportsbook.
What a sportsbook is, in one paragraph
The word comes from the bookmaker’s “book”: the record of every bet taken on an event. A sportsbook (or bookmaker) sets a price for each possible outcome, accepts stakes from players at that price, and pays winners from the pool of losing stakes. Because the prices are set so that the implied chances of all outcomes add up to slightly more than 100%, a well-balanced book earns a small margin whatever the result. An online sportsbook does the same thing in software, across thousands of events a week, pre-match and in-play.
How a bet moves through a sportsbook
- The event and markets appear. A data feed delivers fixtures, teams, start times and the available markets (match result, totals, handicaps, player props and so on).
- Odds are priced. The feed or the operator’s trading team sets odds for each outcome and adds the margin.
- The player builds a bet slip. They choose one selection (a single) or several (an accumulator or bet builder) and enter a stake. How the slip handles stakes, returns and odds changes decides how many of those selections become bets; see bet slip design patterns that reduce drop-off.
- The bet is checked and accepted. Before acceptance the platform checks the balance, the player’s limits, the market’s liability and whether the odds have moved. Live bets often wait a few seconds before acceptance to stop players betting on information the feed has not yet priced.
- The stake leaves the wallet. The player’s balance drops and the bet is recorded as open.
- The event plays out. In-play markets keep updating, suspending during dangerous moments such as a penalty, and reopening after.
- The result is confirmed and bets settle. Winning bets are paid at the accepted odds, losing bets close, and voided bets (for example a postponed match) are refunded.
Every step is a place where an error costs money: a wrong price, a bet accepted after a goal, or a late settlement that floods support with tickets. That is why the platform matters more in sports than in most casino verticals.
Odds and margin, briefly
Odds express both the payout and the chance the bookmaker gives an outcome. In decimal odds, a 2.00 price returns twice the stake, which implies a 50% chance (1 divided by 2.00). Take an illustrative tennis match priced at 1.90 for each player. Each price implies about 52.6%, so the two add up to about 105.3%. The extra 5.3% is the overround: the bookmaker’s built-in margin. If the book takes balanced money on both sides, it pays the winners less than it collected from all stakes.
Real books are rarely balanced, which is why sportsbooks manage liability rather than relying on the margin alone. How margin, overround and hold translate into revenue is a topic of its own; the result shows up in your gross gaming revenue, which we explain in GGR vs NGR.
Pre-match and live betting
| Pre-match | Live (in-play) | |
|---|---|---|
| When | Before the event starts | While the event is running |
| Odds movement | Slow, driven by news and money | Constant, driven by the score, time and play |
| Feed demand | Fixtures, markets, periodic price updates | Low-latency scores and prices, frequent suspensions |
| Main risk | Mispriced markets, team news | Bets placed faster than the feed (courtsiding), delayed suspensions |
| Platform need | Market breadth and clear navigation | Fast bet acceptance with a safety delay, live scoreboard, cash-out |
Live betting usually draws a large share of activity on modern sportsbooks because it gives players something to do during the match. It also asks the most of the data feed and the risk controls.
The parts that make up an online sportsbook
| Component | What it does | Who usually provides it |
|---|---|---|
| Sports data and odds feed | Fixtures, markets, live scores and prices | A specialist data provider, integrated by the platform |
| Front end | Sports lobby, event pages, bet slip, live scoreboard, cash-out | The platform, branded for the operator |
| Trading and risk | Margins, limits, liability per market and per player, suspensions | Platform tools plus the operator’s own settings or a managed service |
| Wallet | Player balance, ideally shared with the casino | The platform |
| Settlement | Grades bets from confirmed results, handles voids and partial results | The platform, driven by the feed’s results |
| Bonuses | Free bets, odds boosts, sports wagering rules | The platform’s bonus engine |
| Back office and reporting | Bets, turnover, GGR, player history, fraud flags | The platform |
| Payments and compliance | Deposits, withdrawals, KYC, responsible-gaming tools | The platform with payment and verification partners; the licence sets the rules |
Sportsbook vs online casino: what changes for the operator
| Online casino | Sportsbook | |
|---|---|---|
| Product | Games from studios, usually through an aggregator | Events and markets priced from a data feed |
| House edge | Fixed by the game’s maths (RTP) | Set by the odds margin and how the book is balanced |
| Results | Instant, per spin or hand | Known only after the event; settlement can take hours or days |
| Revenue pattern | Smooth day to day | Volatile; one upset weekend can turn a month negative |
| Calendar | Always on | Follows the sports calendar: weekends, tournaments, season breaks |
| Risk work | Bonus abuse and fraud | Bonus abuse, fraud, arbitrage, sharp bettors and liability |
The two products support each other. Sports brings players in around big events; the casino keeps them active between matches. That works best when both run on one account and one wallet, so a player can move from a bet slip to a slot without transferring money.
Ways to run a sportsbook
- Build it yourself. Full control, but you build and maintain the front end, risk tools, settlement and integrations. Realistic only with a large engineering and trading team.
- Turnkey or white-label platform. A provider supplies the software and the feed integration; you run the brand, marketing and players. For the difference between the two models, see white label vs turnkey.
- Sportsbook added to an existing casino platform. The most common route for casino operators: same accounts, wallet and back office, with sports as a new section.
Spinlab Studio’s sportsbook follows the third route. It runs on a FeedConstruct sports data feed and is included as sportsbook integration on the Dominate plan and as a premium sportsbook on Lifetime Access, as listed on the pricing page. Markets, sportsbook fees and set-up are discussed on the demo call. The details are on our sportsbook software page.
Frequently Asked Questions
Is a sportsbook the same as a bookmaker?
Yes. “Sportsbook” is the common term in North America and online; “bookmaker” or “bookie” is more common in the UK and Europe. Both describe a business that sets odds and accepts bets on sporting events.
How does a sportsbook make money if it doesn’t know who will win?
It prices every outcome with a margin, so the implied chances add up to more than 100%. Over many bets that margin becomes revenue, provided the book manages its liability on each event.
Do I need a separate licence for a sportsbook?
It depends on the jurisdiction. Some licences cover casino and sports betting together; others license them separately or not at all. Check the licence conditions before you plan the product, and read our Anjouan licence guide for one common route.
What is a sports data feed?
A service that sends the platform fixtures, markets, live scores, prices and official results in real time. It decides which sports and leagues you can offer and how fast live odds update.
Can players use one balance for casino and sports?
On a platform built for both, yes. Whether that applies to your set-up is something to confirm with your provider before launch; with Spinlab it is walked through on the demo call.
Should a new operator launch sports and casino together?
Only if the target market bets on sports heavily and you can staff the risk side. Many operators start casino-first and add the sportsbook once the brand has traction. Our guide on how to start a sportsbook covers that decision.
Next step
If you want to see how a sportsbook sits next to your casino in one platform, book a demo and we will walk through the feed, markets, risk settings and back office for your markets.
