How to Find +EV (Positive Expected Value) Bets in Modern Sports Markets

The Core Math of Every Successful Investor

Whether trading equities, allocating venture capital, or betting on sports, every profitable decision boils down to a single equation: Positive Expected Value (+EV).

Expected Value represents the average amount a bettor can expect to win or lose per wager if the exact same bet were placed hundreds of times under identical conditions.

The Expected Value Formula

EV = (Probability of Winning × Profit) − (Probability of Losing × Stake)

A Simple Coin Toss Example:

Imagine a friend offers to flip a coin with you:

• If it lands on Heads, you win $110.
• If it lands on Tails, you lose $100.

Since a fair coin has a 50% probability of either outcome:

EV = (0.50 × $110) − (0.50 × $100) = $55 − $50 = +$5.00

Every time you take this wager, you are generating +$5.00 in Expected Value (a 5% ROI edge). You might lose the first flip, or the first several. Over hundreds of flips your results tend toward that +5% edge, but a long losing run is still possible along the way, which is why stake sizing matters.

Removing the Vig (The "Hold")

Sportsbooks make money by charging a fee called the vig or juice.

When two balanced teams play, both sides are typically priced at -110 (1.91 decimal) instead of +100 (2.00 decimal):

• Implied probability of -110 = 110 ÷ (110 + 100) = 52.38%
• Adding both sides together: 52.38% + 52.38% = 104.76%
• The extra 4.76% is the bookmaker's theoretical hold.

To find +EV opportunities, quantitative models first calculate the no-vig "fair" probability of an event by stripping out the juice from high-limit market makers (such as Pinnacle or exchanges).

How to Find +EV Bets Yourself

1. Find a sharp reference price: Take the odds for the same market from a high-limit market maker or an exchange.
2. Remove the vig: Convert both sides to implied probabilities and scale them so they add up to 100%. That gives the fair probability.
3. Compare with your sportsbook: If your book's odds imply a lower probability than the fair one, the bet is +EV. The positive EV calculator does steps 2 and 3 for you.
4. Ask why the prices differ: Late injury news or a line that hasn't moved yet can explain a gap. A price that looks too good may simply be out of date.