What is arbitrage in sports betting, and why do the gaps exist?
Arbitrage in sports betting is betting every outcome of a game, each at the sportsbook with the best price, when those prices disagree enough that any winning bet covers all your stakes. You lock in a small profit, usually 1% to 5%, before the game starts. The gaps exist because each book sets its own odds and updates them at its own speed. Arbocado's free arbitrage calculator sizes the bets, and its Arbitrage Finder scans for the gaps.
- Arbitrage in sports betting means betting every outcome of one market at different sportsbooks so any winning bet covers all the stakes.
- An arbitrage exists when the implied probabilities of every outcome add up to less than 100%.
- Price gaps appear because sportsbooks set odds independently, serve different customers, and update lines at different speeds.
- Arbitrage works on moneylines, spreads, totals, and 3-way soccer markets, as long as every leg covers the same line and settles under the same rules.
- The main risks are odds moving before the second bet, voided bets, and account limits. The result of the game isn't one of them.
The short answer
Arbitrage in sports betting means betting on every possible outcome of a game, each at a different sportsbook, when their odds disagree enough that any winning bet pays back more than all your stakes combined. You profit whoever wins.
It works because sportsbooks don't share one price. Each sets its own odds, and for a few minutes one book can be generous on a team while another is generous on its opponent. Taking both sides at the right sizes turns that disagreement into a locked-in return, usually 1% to 5% of the amount staked.
A two-book example
The Lakers are +112 at FanDuel and the Celtics are +108 at DraftKings. Each price alone looks ordinary. Together they imply a 95.3% total chance (47.2% plus 48.1%), and anything under 100% is an arbitrage.
| Bet | Stake | Pays if it wins | Profit |
|---|---|---|---|
| Lakers +112 at FanDuel | $49.52 | $104.98 | $4.98 |
| Celtics +108 at DraftKings | $50.48 | $105.00 | $5.00 |
One bet loses and the other wins, and either way about $105 comes back on $100. For the formulas behind those stakes, read how to calculate arbitrage bets, or plug your own odds into the free arbitrage betting calculator.
Why the gaps exist
Sportsbooks don't hand out free money on purpose. Gaps open for a few ordinary reasons:
- Independent pricing. FanDuel, BetMGM, and Caesars each run their own trading teams and models, so they reach different numbers.
- Different customers. A book with heavy action on the home team shades that price to balance its risk. A book with different customers doesn't.
- Update speed. When news breaks, like a starter ruled out, some books move in seconds and others take minutes.
- Promotions. Boosted odds can push one book's price well past the rest of the market.
Markets you can arbitrage
| Market | Outcomes | What has to match |
|---|---|---|
| Moneyline (NBA, NFL, MLB) | 2 | Same game, same settlement rules |
| Point spread | 2 | The same line on both sides, like -3.5 and +3.5 |
| Total (over/under) | 2 | The same number, like over 220.5 and under 220.5 |
| Soccer 1X2 | 3 | Home, draw, and away, all settled at 90 minutes |
| Tennis match winner | 2 | Matching rules for a retirement mid-match |
Three-way markets need a stake on every outcome, including the draw. The 3-way and lay bet calculator guide walks through one.
What can go wrong
The game result can't hurt a correctly placed arb. These things can:
- Line moves. If the second price changes before you bet it, the edge can shrink or vanish.
- Voided bets. A book can cancel a bet it decides was a pricing error, leaving the other leg unhedged.
- Rule mismatches. If one book voids a tennis bet on retirement and the other settles it, you can lose one leg with nothing coming back on the other.
- Account limits. Books cut stakes for accounts that win steadily. See how to avoid sportsbook limits.
None of these make arbitrage illegal. It's legal wherever sports betting is legal, as covered in is arbitrage betting legal and profitable.
How people find arbs
You can find arbs by comparing odds across sportsbook apps by hand, but gaps often close in minutes. Most arbitrage bettors use arbitrage betting software that checks every book at once and flags any market adding up to under 100%.
Scan every book at once
Arbocado's Arbitrage Finder checks DraftKings, FanDuel, BetMGM, Caesars, and more for sure bets, and shows the stake for each side.
Open the Arbitrage FinderReady to place one? Read how to arbitrage bet step by step, or see which sportsbooks to open first.
Frequently asked questions
What is arbitrage in sports betting in simple terms?
It's betting both sides of a game at two different sportsbooks when their odds disagree enough that whichever side wins pays back more than your total stake. For example, +112 on one team at FanDuel and +108 on the other at DraftKings returns about $105 on $100 either way.
Why do sportsbooks offer arbitrage opportunities?
They don't mean to. Each book sets its own odds based on its own customers and risk, and lines update at different speeds. For a few minutes, one book's price can drift far enough from another's that backing both sides guarantees a profit.
Is an arbitrage bet a sure bet?
In the math, yes: if every bet stands at the odds you took, you profit whatever the result. The real-world risks are a line moving before you place the second leg, a book voiding a bet as a pricing error, or two books settling the same market under different rules.