Arbitrage Betting Guide — How to Find and Exploit Arb Opportunities
Arbitrage betting, often called "arbing," is a strategy that exploits pricing differences between bookmakers to guarantee a profit regardless of the outcome. When two or more sportsbooks disagree enough on the probability of an event, it becomes possible to bet on all outcomes and lock in a risk-free return. While individual arb profits are typically small (1-5%), the strategy is mathematically guaranteed to work and has attracted sophisticated bettors for decades.
How Arbitrage Works
Arbitrage exists when the sum of implied probabilities across all outcomes is less than 100%. For a two-outcome event, if Platform A offers Team A at 2.15 (implied probability 46.5%) and Platform B offers Team B at 2.15 (implied probability 46.5%), the total implied probability is 93.0%. Since this is below 100%, an arbitrage opportunity exists. By splitting your bankroll proportionally, you can guarantee a profit of approximately 7.5% regardless of which team wins. The key formula is: Arb% = (1/Odds1 + 1/Odds2) x 100. If the result is less than 100, an arb exists.
Calculating Optimal Stakes
To calculate the optimal stake for each outcome, divide the inverse of each outcome's odds by the sum of all inverse odds, then multiply by your total bankroll. For example, with odds of 2.15 and 2.15 on a $1,000 bankroll: Stake A = (1/2.15) / (1/2.15 + 1/2.15) x $1,000 = $500. Stake B = $500. If Team A wins, you receive $1,075 (a $75 profit). If Team B wins, you also receive $1,075. This guarantee is what makes arbitrage betting so appealing.
Where to Find Arb Opportunities
Arbitrage opportunities arise from several sources. Different sportsbooks use different models and have access to different information, leading to pricing discrepancies. New markets are particularly prone to mispricing as odds are still being established. Live betting creates frequent short-lived arbs as different platforms react to in-game events at different speeds. The emergence of prediction markets like Polymarket and Kalshi has created an entirely new layer of pricing to compare against traditional sportsbooks.
Cross-Platform Arbitrage
The most common form of sports arbitrage involves comparing odds between two or more sportsbooks. For example, a tennis match might have Player A at 2.30 on Pinnacle but Player B at 1.90 on DraftKings. With prediction markets entering the scene, you can now also compare sportsbook odds against Polymarket or Kalshi prices. These cross-platform discrepancies tend to be larger because prediction markets and sportsbooks use fundamentally different pricing mechanisms.
Risks and Limitations
Despite being theoretically risk-free, arbitrage betting has practical risks. The most significant is odds movement: by the time you place your second bet, the odds may have changed, eliminating the arb. Account limitations are another concern, as sportsbooks may restrict or close accounts they suspect of arbing. Maximum bet limits can prevent you from placing the full optimal stake. Currency exchange rates add complexity for cross-border arbs. And some platforms have different settlement rules that can turn a guaranteed profit into a loss in edge cases.
Three-Way Arbitrage
Three-way markets, common in soccer (home/draw/away), offer more arbitrage opportunities because there are three prices that must align. The more outcomes and platforms involved, the more likely it is that at least one combination creates an arb. However, three-way arbs are harder to execute because you need to place three bets quickly before any odds change. The profit margins tend to be thinner, and the execution risk is higher.
Tools for Finding Arbs
Manual arb finding is impractical in modern markets because odds move too quickly. Tools like the OddsBridge arbitrage checker automate the calculation, showing you whether an arb exists, the guaranteed profit, and exactly how much to stake on each outcome. Our odds comparison table highlights pricing discrepancies across platforms in real time, making it easy to spot potential arbs before they disappear.
Is Arbitrage Betting Legal?
Arbitrage betting is legal in most jurisdictions. You are simply placing bets at different sportsbooks, which is a perfectly lawful activity. However, sportsbooks are private businesses and reserve the right to limit or close accounts for any reason, including suspected arbing. This is the biggest practical barrier to sustained arb betting. Many arbers mitigate this by mixing arb bets with recreational bets, using multiple accounts (where permitted), and focusing on markets where limits are higher. Prediction markets are generally more arb-friendly since they operate as exchanges rather than traditional bookmakers.