Arbitrage betting, often shortened to arbing, is a strategy that seeks a guaranteed profit by covering every outcome of an event using odds from different operators. When one bookmaker prices an outcome more generously than another, the combined prices can occasionally produce a market whose implied probabilities add up to less than 100%, creating a mathematical surplus.
The method requires splitting the total stake across outcomes in proportion to their odds, so that whichever result occurs returns the same amount. If that return exceeds the total staked, the profit is locked in before the event begins.
Consider a hypothetical two-way market. One operator prices outcome A at decimal odds of 2.10, while another prices outcome B at 2.10. The implied probabilities are each 1 ÷ 2.10 = 47.6%, summing to about 95.2%. Staking 50 on each outcome from a 100 bankroll returns 105 whichever side wins, a guaranteed profit of 5, or roughly 5%.
A common misconception is that arbitrage is risk-free. In practice several risks remain: odds can change before both bets are placed, a stake may be rejected or limited, one leg can fail to register, and errors in calculation can erase the margin. Operators also frequently restrict or close accounts they identify as arbitrage-focused, and many list such activity as a breach of their terms.
Arbitrage opportunities are typically small, often a few percent, and disappear quickly as operators adjust prices. They also require significant capital spread across multiple accounts to generate meaningful returns. The legality and operator tolerance of arbitrage vary between jurisdictions and providers, so bettors should review the applicable terms and local regulations before attempting it.