Understanding Positive Expected Value (EV)
Dive deep into EV calculations and why they matter for long-term betting success.
What is Expected Value?
Expected Value (EV) is a statistical measure that calculates the average result of a bet if it were placed many times. A bet with a positive EV means you are likely to make a profit in the long run.
In betting terms, it balances the probability of winning against the reward for that win. When you bet with a positive EV, you're placing a mathematically advantageous wager.
How to Calculate Expected Value
The formula for EV is:
EV = (P_win × Win_Amount) + (P_loss × Loss_Amount)
Where:
- P_win = Probability of winning (as a decimal)
- Win_Amount = Profit if you win
- P_loss = Probability of losing (1 - P_win)
- Loss_Amount = Amount lost (usually -1x your bet)
Sample EV Calculation
Let’s say you're placing a $10 two-pick entry on PrizePicks. If both picks hit, you get $30 back ($20 profit). If either misses, you lose the $10.
Let’s assume each prop has a 60% chance of hitting. Since both need to hit:
Combined Probability = 0.6 × 0.6 = 0.36 (or 36%)
Now plug into the EV formula:
EV = (0.36 × 20) + (0.64 × -10) EV = 7.2 - 6.4 = +0.80This means, on average, you’d earn $0.80 profit per $10 bet with this combination over time.
The Strategy
To consistently profit, focus on finding props where your estimated win probability is significantly higher than what the payout implies. This is where OddsProphet helps by showing you True Win % from sportsbook data.
Your edge grows when you:
- Pick combinations where each leg has at least a 54–65% win probability
- Avoid low-value props or ones with inflated lines
- Track results over time to validate your edge
- Always play promos (e.g. discounted plays, free squares, payout boosts), as these significantly increase your Expected Value.
The math is simple: More high-probability picks = More Positive EV. Stack the odds in your favor, and let the numbers work for you.