Strategy
Arbitrage
Also called arb, sure bet
Betting both sides at different books at prices that guarantee a profit whatever happens.
When two sportsbooks disagree enough that the implied probabilities of both sides together add up to less than 100%, backing both in the right proportion locks in a profit regardless of the result.
Real arbs exist but are small, short-lived and operationally demanding: you need accounts everywhere, funds spread across them, and the speed to place both legs before one moves. Typical returns are 1–3%.
The bigger cost is attention from the books. Arbitrage is trivially detectable and sportsbooks limit or close accounts for it quickly, which is why most serious bettors treat it as incidental rather than a strategy.
Want the full version? Read the in-depth guide, with worked examples and the math.
See also
- Middle — Betting both sides at different numbers so that certain results win both bets.
- Hedge — Betting the opposite side of a wager you already hold to reduce risk or lock in profit.
- Line shopping — Checking multiple sportsbooks for the same bet and taking the best available price.
- Limit — The maximum a sportsbook will accept on a market — or on you specifically.