What Is +EV Sports Betting?
A positive-EV bet is one where your estimate of the true win probability beats the probability baked into the price. Over the long run, it's the only edge that compounds.
What expected value means
Expected value (EV) is the average result of a bet if you could make it many times over. A bet is positive-EV when your estimated chance of winning is higher than the chance implied by the odds.
It's the difference between betting on a hunch and betting because the price is genuinely in your favor.
The formula
EV multiplies what you win by how often you win, then subtracts what you lose by how often you lose. If the result is positive, the bet is worth making — repeatedly.
EV = (win probability × profit) − (loss probability × stake)
At +120 with a 55% true chance: 0.55 × $120 − 0.45 × $100 = +$21 per $100 risked.
Finding +EV bets
The practical method: estimate true probability from the sharpest markets (which have the lowest vig and the smartest money), remove their margin, and compare to the price at a beatable book.
When the gap is large enough to clear your estimation error, variance, and friction, you have a +EV play. Small, well-founded edges beat big, hopeful guesses.
Key takeaways
- +EV means your true win probability exceeds the price's implied probability.
- EV = (win prob × profit) − (loss prob × stake); positive means bet it.
- Estimate true probability from sharp, low-vig markets.
- +EV is a long-run edge — it does not promise a win on any single bet.
Common mistakes
- Believing +EV guarantees this particular bet wins — it doesn't; it pays off over many bets.
- Overestimating your own probability and manufacturing an edge that isn't there.
- Betting edges so thin that vig and limits erase them.
FAQ
Is a 1% edge enough?
Mathematically yes. In practice, account for estimation error and friction — many disciplined bettors target 2%+ before firing.
How do I avoid -EV bets?
Skip high-vig markets like same-game parlays and exotic futures, and stick to competitive prices on main markets.
Does +EV mean I'll win this bet?
No. It means the bet is profitable on average over many repetitions. Any single bet can lose — that's variance, not a flaw in the edge.
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