Arbitrage betting (an "arb") means betting both sides of the same game at two different sportsbooks, at prices that guarantee a profit whichever side wins.
See today's live arbs ›Every sportsbook sets its own prices, and they don't all move at the same speed. When news hits or money comes in, one book adjusts and another lags for a few minutes. For that short window, the two books disagree enough that the best price on each side adds up to less than the full 100%. That gap is your profit.
Say FanDuel has a player's points at Over 32.5 for +142 and DraftKings has Under 32.5 for -112. +142 implies a 41.3% chance and -112 implies 52.8%. Together that's 94.1%, under 100%, so it's an arb. Split $100 like this:
If the over hits, $43.89 at +142 pays $106.21. If the under hits, $56.11 at -112 also pays $106.21. You made $6.21 on $100 without caring who won. Plug in your own prices with the arbitrage calculator.
Arbs are low risk, not no risk. A price can move between your two bets. A book can void a bet it says was a pricing mistake. Exchanges charge fees that eat into small arbs. And sportsbooks don't like arbers: some will limit accounts that only bet off prices. Betting normal-looking amounts (the calculator can round to $5) and not only betting arbs helps.
Yes. It's just placing bets at more than one sportsbook, which is legal anywhere sports betting is. Sportsbooks can still limit or close accounts they don't want.
Most arbs pay 1% to 5% of what you stake. The return is small per bet, so it adds up through volume, and it depends on how many books you can bet at.
Often only a few minutes. A typical arb closes as soon as the slow book catches up, which is why the live page refreshes about every minute.
The more books you have, the more arbs you can take. Use 'My books' on the arbs page to only see arbs at the books you have.