Arbitrage Betting

Arbitrage means betting every outcome of an event across different books at prices that guarantee a profit regardless of the result. The maths is real, the opportunities exist, and the practical obstacles are large enough that most people who try it stop within a year.

The Maths

Convert every outcome to implied probability and add them. If the total is below 100%, an arbitrage exists.

Example. Book A has Team X at +115 (46.5%). Book B has Team Y at -105 (51.2%). Total: 97.7%. Betting both in the right proportion returns about 2.3% of total stake regardless of who wins.

Stakes are set inversely to the prices. On a 1,000 total outlay, roughly 476 on the +115 side and 524 on the -105 side produces about 1,023 back either way. The profit is small, certain, and requires having both bets accepted at those prices.

Two-way arbitrages are the common case. Three-way markets in soccer create more opportunities and require more precise execution.

Where Arbitrages Come From

Books moving at different speeds. One reprices after news, another lags. This is the most common source and it lasts seconds to minutes.

Promotional pricing. Odds boosts and enhanced prices, deliberately generous, can be arbed against a normal book.

Errors. Typos and model failures. Rare, large, and frequently voided by the book afterwards.

Differing correlation models. Mostly in derivative markets rather than main lines.

The margins available are typically 1 to 3%. On a 500 arb that is 5 to 15, which sets the realistic scale: arbitrage is a grind requiring volume, capital spread across many accounts, and constant attention.

Why It Ends

Books do not want arbitrage volume, and they identify it easily.

The signature is unmistakable: bets placed within seconds of a price appearing, always at the best available number, always at odd stake amounts calculated from the other side, never on promotional products, immediate withdrawal of winnings. No sophisticated detection is required.

Most arbitrage bettors find their useful accounts exhausted within months. And the accounts burned are the same accounts a value bettor needs for line shopping, which is the real cost. See account limits.

The Practical Risks

Only one leg lands. The price moves before the second bet is placed and you hold an unhedged position at a bad number. This is the most common way arbitrage loses money.

Rule differences. Books differ on overtime, void conditions, player-withdrawal handling and what counts as a settled market. A pair of bets that looks matched can settle differently.

Voided legs. If one side is voided and the other stands, the arbitrage becomes a straight bet you never wanted.

Capital drag. Money must sit in multiple accounts simultaneously, unavailable for anything else.

Time. Monitoring feeds and executing quickly is genuine work for returns measured in single-digit percentages of the amount deployed.

The Honest Assessment

Arbitrage is real and it is a poor use of a bettor's resources.

It converts finite, valuable sportsbook access into small guaranteed returns, when that same access is the precondition for line shopping, which is the highest-return habit in ordinary betting. Burning accounts for 2% arbs to lose the ability to take -105 instead of -110 for years is a bad trade.

The related practice of value betting — taking clearly mispriced numbers at soft books without hedging — has higher expectation, attracts limits more slowly, and is the same skill applied more patiently. See line shopping and expected value.

Frequently Asked Questions