Arbitrage Betting Explained: How It Works and Why It Is Hard
Arbitrage betting means betting both sides of the same game at two different sportsbooks, at prices that guarantee a small profit whichever side wins. It only exists when the books disagree by enough to cancel out the vig.
How arbitrage betting works
Convert each price to an implied probability and add them. If the total is under 100%, there is an arbitrage. At +105 and +105 the two sides are 48.8% each, a total of 97.6%.
- 1Find two prices that add to under 100%They will be at different sportsbooks. One book never offers an arb against itself.
- 2Size the stakesBet more on the lower price so both results return the same amount.
- 3Place both bets quicklyThe gap closes in minutes, sometimes seconds.
Our implied probability guide has the conversion formulas.
Is arbitrage betting legal?
Yes. Placing legal bets at licensed sportsbooks is legal, and betting both sides breaks no law. Sportsbooks do not like it, though, and their terms let them restrict accounts.
The real risks of arbitrage
- Limits: books cut the stakes of accounts that only bet off-market prices. We explain why in why sportsbooks limit winning bettors.
- One leg fails: a price moves or a bet is rejected after the other side is placed.
- Voided bets: a book can cancel a bet made at an obvious pricing error.
- Different rules: two books can grade the same bet differently, for example on overtime or a pitcher change.
- Small margins: most arbs are 1 to 3%, so you need large stakes and many accounts.
Arbitrage, middling and hedging
All three involve both sides of a game. Arbitrage locks in profit from the start. A middle risks a small loss for a chance to win both bets. A hedge is a second bet made later to protect an existing one.
For most bettors the useful habit is the one underneath arbitrage: comparing prices. Getting +105 instead of -105 on the same bet is free value. Our sportsbook reviews and live betting odds page help with that.