Expected Value (EV) is probably the most important concept in sports betting and sports trading. It is the mathematical tool that separates professional bettors from amateurs.
What Is Expected Value (EV)?
Expected Value represents the average profit or loss you expect per bet over time. In simple terms: if you made the same bet thousands of times, EV tells you how much you would win or lose on average per bet.
- 📈 Positive EV (+EV) — The bet is profitable long-term
- 📉 Negative EV (-EV) — The bet is harmful long-term
- ⚖️ Zero EV (0 EV) — Neither win nor lose long-term
The EV Formula
The formula is simple:
EV = (Win Probability × Profit) - (Loss Probability × Stake)
Practical Example
Imagine a bet at odds of 2.50 on an event with a 45% real probability:
- Stake: €10
- Profit if won: €10 × 2.50 - €10 = €15
- EV = (0.45 × €15) - (0.55 × €10)
- EV = €6.75 - €5.50 = +€1.25
👉 This bet has a positive EV of €1.25. On average, you gain €1.25 for every €10 staked in this situation.
How to Identify +EV Bets
1. Estimate the Real Probability
Use statistics, mathematical models, or your analysis to determine the real probability of an event. Compare it to the implied probability of the odds.
2. Calculate the Implied Probability
Implied Probability = 1 / Odds
Example: Odds of 2.50 → Implied Probability = 1/2.50 = 40%
If you believe the real probability is 45% and the market says 40%, you have a +EV bet.
3. Compare with the Market
On exchanges like Orbit Exchange, odds reflect the collective market opinion. When you find a discrepancy between your estimate and the market, you have an opportunity.
EV in Sports Trading
In trading, EV applies differently. Instead of waiting for the final result, you trade based on odds movements:
- If you expect odds to drop (e.g., favorite scores first goal), you Back at high odds
- When odds drop, you Lay to close with profit
- Your EV is positive if your odds movement prediction is correct more often than not
Common EV Mistakes
- ❌ Overestimating probability — Tendency to be too optimistic
- ❌ Ignoring the margin — Traditional bookmakers include margin that reduces your EV
- ❌ Small sample size — You need hundreds of bets for EV to manifest
- ❌ Confusing outcome with decision — A +EV bet can lose; that doesn't make it a bad decision
Frequently Asked Questions
If I have positive EV, why do I lose bets?
EV is a long-term concept. You can lose several bets in a row and still have positive EV. You need volume — think hundreds or thousands of bets.
How can I improve my EV?
Use exchanges like Orbit Exchange (lower commissions = better EV), improve your statistical analysis, and be disciplined in bet selection.
Does EV work in live trading?
Yes, absolutely. In live trading, your EV depends on your game-reading quality and execution speed. Using good trading software is essential.
Article by the BetAdvisor-PRT Team | Read more articles