What's the difference between +EV betting and arbitrage?

Q: What's the difference between +EV betting and arbitrage?

Arbitrage means betting every outcome of an event at different sportsbooks whose prices disagree enough that the implied probabilities sum to less than 100%, locking in a small guaranteed profit. +EV betting means taking one side at a price better than its fair value and accepting that the individual bet can lose. Arbitrage has near-zero variance and thin margins; +EV has high variance and larger long-run returns.

Strategy

3 diagrams•5 min read•Updated Aug 17, 2026

Written by VIMB

Short answer

Arbitrage = guaranteed small profit, both sides, no opinion required. +EV = risky single side, bigger edge, requires an opinion you can defend.

Both strategies start from the same observation: sportsbooks disagree with each other. What you do with that disagreement is what separates them.

Two shapes of bankroll curveSame market inefficiency, two very different risk profiles.

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Arbitrage: bet everything, guarantee a profit

An arbitrage exists when the implied probabilities of every outcome, taken at the best available price across books, add to less than 100%. Say Book A has Team A at +115 (46.5%) while Book B has Team B at -105 (51.2%). Those sum to 97.7%, a market with a 2.3% hole in it.

A market with a hole in itBest prices across two books, adding to less than 100%.

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$1,000 split: $475.91 on +115, $524.09 on -105

Either result returns $1,023.22, a locked $23.22, about 2.3%, before any account frictions.

Splitting the stake$1,000 divided so that both outcomes return the same amount.

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You don't need an opinion about the game. You don't even need to know which sport it is. You need two accounts, enough bankroll on both sides, and the speed to place both legs before one of the prices moves.

+EV: bet one side, accept the variance

The +EV bettor looks at the same two prices and reaches a different conclusion: one of these books is wrong, and I'm going to take the wrong price without hedging it. There's no guaranteed profit. There's a bigger edge per bet and a much longer wait to find out whether you were right.

	Arbitrage	+EV
Outcome risk	None if executed correctly	Every bet can lose
Typical edge	Small, often 1–3%	Larger per bet
Bets per opportunity	All outcomes	One side
Bankroll needed	High, capital sits on both sides	Lower per opportunity
Needs an opinion?	No	Yes, it's the whole thing
Time to know if it works	Immediately	Hundreds of bets

The risks arbitrage actually carries

'Risk-free' describes the math, not the activity. The real exposure sits in execution and account management:

▸One leg lands, the other price moves before you get it down, and you're now holding a naked position you never wanted.

▸A book voids or re-settles a bet on a palpable-error or wrong-line rule, leaving the other leg live.

▸Rules differ between books on overtime, pitcher changes and cancellations, so the two 'opposite' bets aren't always truly opposite.

▸Bonus-restricted or max-bet-limited accounts cap the size at which any of this is worth the effort.

▸Sportsbooks actively look for this pattern. Limiting and account closure is the normal end state, not a rare one.

They aren't rivals

Most people who do one end up doing both. The underlying skill is identical: knowing the fair price and having accounts everywhere. Arbitrage is what you do with a guaranteed hole; +EV is what you do with a price you merely believe is wrong.