What Is Arbitrage Betting?
Arbitrage betting is the practice of backing every outcome of an event at prices that secure a guaranteed profit.
It occurs when the best available odds across bookmakers imply a combined probability of less than 100%. In those cases, stakes can be allocated across each outcome so that total return exceeds total stake, regardless of the result.
Implied probability is calculated as:
Example
Because total implied probability is below 100%, this market presents an arbitrage opportunity. OddsOtter helps surface these setups by comparing a wide range of bookmakers to build the strongest best-odds view. See More Books, Better Prices for more on why broader bookmaker coverage improves arbitrage opportunities.
Hedging an Opportunity
OddsOtter includes a hedge calculator feature that automatically shows the required stake on the other side once your first bet is placed, whether you want to fully balance the return or lean slightly toward the favourite or the underdog.
In the tables below, Recommended Stake is the amount OddsOtter calculates for that specific bookmaker and outcome. Total Stake is your combined exposure after both bets have been placed, and Profit shows the resulting outcome after both bets are accounted for.
Option 1: Equal profit on both outcomes
Option 2: Hedge toward the favourite
Compared with Option 1's $11.11 profit (100% chance), this increases the upside to $21.43, but that outcome now depends on the favourite winning at an implied probability of 1 / 1.95 = 51.28%.1
Option 3: Hedge toward the underdog
This is the highest payout of the three options at $23.08, but that outcome now depends on the underdog winning at an implied probability of 1 / 2.10 = 47.62%.1
1 Implied probability is derived directly from the quoted odds and is not the same as true probability. For more on that distinction, see Positive EV Betting.
Please Note
While arbitrage is mathematically risk-free in theory, execution risk can still arise in practice.
- Odds movement — quoted prices may change before all legs are placed, which can remove the arbitrage margin. OddsOtter limits displayed odds to fresh data updated within the last 10 minutes, but prices can still move while you are placing the bets.
- Data extraction errors — sportsbook feeds and third-party data extraction are not perfect. OddsOtter reduces this risk with freshness checks, but displayed prices can still be incorrect, delayed, or unavailable at the bookmaker.
- Stake availability — bookmakers may limit the amount that can be placed at a given price, preventing the intended position size.
- Rule differences — settlement terms, overtime treatment, void conditions, and deductions may vary across operators and affect the final outcome.
- Account restrictions — repeated arbitrage activity may lead to reduced limits or account restrictions with some bookmakers.