What does +EV mean in betting?

Q: What does +EV mean in betting?

+EV (positive expected value) means a bet's average result across many repetitions is a profit. You calculate it by multiplying your estimated win probability by the profit, then subtracting the loss probability times the stake. If your estimate says a bet wins 55% of the time and it's priced at -110 (which only requires 52.38%), the bet is +EV by about $5 per $100 risked.

Strategy

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

Written by VIMB

Short answer

EV = (win% × profit) − (loss% × stake). Positive means the price is better than the real odds. A +EV bet can and often will lose.

Expected value is the average amount a bet returns if you could place it an unlimited number of times. It's the difference between what you think will happen and what the price says will happen, converted into dollars.

The calculation

EV = (win probability × profit if it wins) − (loss probability × amount risked)

Take a bet you believe is a 55% proposition, priced at -110. A $100 stake at -110 wins $90.91.

A 55% opinion at -110The price only requires 52.38%. Everything above that is the edge.

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(0.55 × $90.91) − (0.45 × $100) = $50.00 − $45.00 = +$5.00

A 5% expected return on money risked.

The shortcut version: -110 requires a 52.38% win rate to break even. You think it's 55%. You're getting paid on a 2.6-point gap.

Where the edge livesThe gap between what the price needs and what you think.

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The part everyone skips

That entire calculation rests on one input you cannot look up: your 55%. The price is a fact; your probability estimate is a claim. If your real hit rate on those bets is 51%, the identical arithmetic produces a losing bet. Most people who think they're betting +EV are simply mis-estimating the first number.

How much your estimate mattersExpected value per $100 at -110, across true win rates.

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Where honest estimates come from

Comparing your number to a no-vig market price is the sanity check. If the sharpest market in the world says 52% and you say 62%, the burden of proof is on you to explain what you know that the money doesn't.

+EV bets lose constantly

A 55% bet loses 45% of the time. Five in a row lose about 1.8% of the time, which across a season of hundreds of bets means five-bet losing streaks are routine, not evidence of a broken model. This is the single hardest part of +EV betting. The feedback is slow and noisy, and it lies to you while you wait.

What losing runs look likeHow often consecutive losses happen, for a 55% bettor and a coin flip.

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It's also why bet sizing matters as much as bet selection. An edge you can't survive the variance of isn't an edge you get to keep.