Arbitrage happens when sportsbooks disagree enough that you can bet every outcome and profit whatever happens. It's possible when the best odds for each side add up to under 100% implied probability.
Returns are small, usually 1% to 5%, and odds move fast. Sportsbooks often limit accounts that arb regularly.
It's an extreme form of line shopping.
How it works
Arbitrage works because sportsbooks don't always agree on a price. If one book has a team at +110 and another has the other side at -102, the two prices together can add up to less than 100% implied probability, leaving a small guaranteed margin.
In practice, it's harder than it sounds:
- Prices move fast. By the time you place the second bet, the odds may have changed, leaving you with a one-sided bet.
- Returns are small. Most arbs return 1% to 5%, so a lot of money has to be staked for a modest profit.
- Sportsbooks limit arbers. Accounts that regularly bet arbitrage are often restricted.
- Rules differ. Different settlement rules for voids, overtime or retirements can turn a sure thing into a loss.
The safest approach is to place the harder bet first, usually the one most likely to move, and to check both sportsbooks' rules for the market.
It's also worth knowing that arbitrage is generally legal, but often against sportsbook terms. The arbitrage calculator works out stakes for two- and three-way markets.
Examples
- Example 1
+110 at one sportsbook and -102 at another: stake $48.53 and $51.47 of $100, and either side returns $101.92, a $1.92 profit.
- Example 2
A soccer match at 2.60, 3.50 and 3.20 (home, draw, away) across three books totals 98.3% implied. $200 split as $78.27, $58.14 and $63.59 returns about $203.49 whatever happens.
- Example 3
The +110 moves to +100 before you place the second bet. Now the prices add up to about 100.5% implied, and there's no arbitrage left.
Common questions
Is arbitrage betting risk-free?
Not in practice. Odds can change before both bets are placed, settlement rules can differ between sportsbooks, and accounts may be limited. The maths guarantees a profit only if every bet is placed and settled as planned.
How do you find arbitrage bets?
By comparing odds across many sportsbooks, usually with odds comparison or arbitrage software. Opportunities are rare and tend to disappear within minutes.