What is arbitrage betting?

Arbitrage betting (arbing) means placing bets on all outcomes of the same event at different bookmakers at odds that guarantee a profit regardless of result. It exists when the combined implied probabilities across books sum to less than 100%.

Is arbitrage betting risky?

The mathematical profit is guaranteed if executed correctly, but practical risks include odds changes between placing bets, account restrictions from bookmakers who detect arbing, and maximum stake limits that prevent full coverage.

How do you find arbitrage opportunities?

Calculate the sum of implied probabilities (1/odds) across all outcomes at the best available price from different bookmakers. If the total is below 100%, an arb exists. Dedicated arb finder services automate this scanning process.

Arbitrage Betting (Arbing) Explained

How an Arbitrage Opportunity Arises

Different bookmakers independently price the same event. Occasionally, their disagreement is large enough that the combined implied probability across the best available price on every outcome falls below 100% — meaning you can back every outcome and guarantee a profit no matter what happens.

Identifying an Arbitrage

Sum of (1 ÷ Best Odds for Each Outcome) < 100% = Arbitrage Exists

Worked Example

A two-outcome tennis match. Bookmaker A offers Player 1 at 2.10. Bookmaker B offers Player 2 at 2.25.

Implied probability Player 1 (Book A): 1 ÷ 2.10 = 47.6%
Implied probability Player 2 (Book B): 1 ÷ 2.25 = 44.4%
Total: 92.0% — an 8% arbitrage margin exists

Calculating Stakes for a Guaranteed Profit

        Stake on Outcome X = (Total Budget × Implied Probability of X) ÷ Total Implied Probability
      

With a $1,000 total budget across the example above:

Stake on Player 1: ($1,000 × 0.476) ÷ 0.920 = $517
Stake on Player 2: ($1,000 × 0.444) ÷ 0.920 = $483

Whichever player wins, the payout works out to approximately $1,086 — a guaranteed ~8.6% profit on the $1,000 outlay, regardless of outcome.

Why Arbitrage Is Hard in Practice

Opportunities are rare and small — true arbs typically offer 1-3% returns and disappear within minutes as books adjust.
Requires multiple funded accounts across several bookmakers simultaneously, with capital split across all of them.
Bookmakers actively detect and restrict arbers — accounts placing suspiciously balanced bets are often limited quickly.
Execution risk. Odds can move between identifying the arb and placing both bets, turning a guaranteed profit into a loss if one leg doesn't get matched at the expected price.
Software/scanning tools are typically required to spot opportunities fast enough — manual scanning across dozens of books is impractical at scale.

Arbitrage vs Value Betting

Arbitrage guarantees a small profit on every position taken — it's a pricing inefficiency, not a probability edge. Value betting accepts variance in exchange for genuine long-term edge on each individual bet. Arbing offers lower risk per opportunity but is operationally harder to sustain due to account restrictions and the sheer rarity of viable arbs.