How arbitrage betting works
Arbitrage betting is a way to lock in a profit no matter who wins. You place one bet on each side of the same game at two different sportsbooks, and because the two books disagree on the odds, the math works out so you come out ahead either way.
A worked example on $100
Say the Lakers play the Celtics. It is a two-way market, so exactly one of them wins. Two sportsbooks price the game a little differently, and that gap is all you need.
Bet on the Lakers
FanDuel
Moneyline
Bet on the Celtics
DraftKings
Moneyline
FanDuel lists the Lakers at +112 and DraftKings lists the Celtics at +108. Both are plus money, which means each book is paying you more than a dollar of profit for every dollar risked. Because you are backing opposite outcomes at two different books, one of your two bets is guaranteed to win. The trick is sizing each bet so the winning side always returns about the same amount. Out of your $100, you put $49.52 on the Lakers and $50.48 on the Celtics.
If the Lakers win
If the Celtics win
Either way, about $105 comes back on your $100.
That is close to $5 of guaranteed profit, no matter who wins the game.
Why the profit is there
Every set of odds carries an implied probability, which is the chance the book is quietly pricing in. When you add up the implied probabilities of both sides at a single book, they always total more than 100 percent. That extra slice is the house edge, and it is why betting both sides at one book loses money.
Arbitrage flips that on its head. By taking the Lakers at FanDuel and the Celtics at DraftKings, the two implied probabilities add up to less than 100 percent. That gap is your edge, and it is what turns into guaranteed profit once you size the bets correctly.
The math in one glance
The two sides add up to 95.3 percent, so about 4.7 percent is left over for you. That leftover is the arbitrage.
A few things to keep in mind
- You need an account at both books and enough money in each so you can place both sides before the odds move.
- Odds shift quickly. The gap that makes an arbitrage can appear and disappear within minutes, so speed matters.
- Always place both bets. If you only get one side down and the line moves, you are left with an ordinary bet rather than a sure thing.
Which sportsbooks can you use?
Arbitrage works best when you can shop the same game across several books, so the first step is knowing which ones you can actually reach. Pick your state and we will show you every sportsbook and exchange available there. We set your state automatically from your location, and you can change it anytime.
Once you have a few of these, the free Arbitrage Finder scans them all in real time and sizes every bet for you, so you can spot and place sure bets in seconds.
