Bet on all outcomes to guarantee a profit no matter who wins.
Arbitrage betting (or "arbing") is a strategy where you bet on all possible outcomes of an event across different sportsbooks, guaranteeing a profit regardless of the result. This works because different books sometimes disagree on the odds enough that you can lock in a positive return.
For example, if Book A offers +150 on Team A and Book B offers +150 on Team B, you can bet the right amounts on both sides and profit no matter who wins. The key is finding odds where the combined implied probabilities add up to less than 100%.
In practice, true arbitrage opportunities are rare and usually small (1-3% profit). They disappear quickly as odds adjust. Most bettors use arbing as a risk-free way to clear bonuses or maintain account activity, rather than as a primary income source.
An arbitrage result only works if every side can be placed at the displayed price. Confirm both outcomes are still live, the bet limits cover the suggested stakes, and each sportsbook grades the market the same way before committing money.
The key signal is total implied probability under 100%. If the combined price moves above 100%, the guaranteed-profit setup disappears and the calculator will show the remaining hold instead of a true arb.
Be careful with stale odds, player props with different rules, pushes, voids, overtime rules, and alternate lines. Small arbs can turn negative quickly if one side changes or if a book only accepts part of the stake.
Use related Upside tools to shop game lines, compare optimizer workflows, and review broader +EV opportunities before relying on a narrow price gap.