Arbitrage Betting Explained: Guaranteed Profit and the Catch

Arbitrage betting — or "surebets" — is when the odds across different bookmakers on the same event let you back every outcome and lock in a profit no matter what happens. It sounds too good to be true. The maths is real; the catch is in the practicalities.

How an arbitrage works

An arb exists when the combined implied probability of a market is below 100%. Add up 1/odds for each outcome using a margin calculator: if the total is under 100%, you can stake each outcome so that every result returns the same payout — for more than you put in.

Example: Book A prices the home side at 2.10 and Book B prices the away side at 2.10. Combined implied probability is 47.6% + 47.6% = 95.2% — a 4.8% arb. Stake each side to equalise the payout and you profit whichever way it goes.

Calculating the stakes

Each outcome should be staked so it returns the same amount: for a target payout P, the stake on odds O is P / O. Getting this exactly right by hand is fiddly — our free arbitrage calculator splits a total stake across the outcomes and shows your guaranteed profit instantly.

The catch (why arbs aren't free money)

• Odds move. Prices can change before you place all legs, turning a sure thing into a loss.
• Limits and voids. Soft books cap stakes and can void bets; you might get one leg on but not the other.
• Account restrictions. Books quickly limit or ban accounts that only arb.

Because of this, most sharp bettors treat arbitrage as a side effect of value betting rather than a strategy in itself — chasing +EV prices naturally produces arbs, without the red flag of only ever betting surebets.

Arbitrage vs hedging

Arbitrage locks in profit before the event using two opposing prices. Hedging is similar but usually done after a bet has moved in your favour — you back the other side to guarantee a return. A hedge calculator shows exactly how much to lay on the opposite outcome to lock in your profit.