Guide
What is positive EV (+EV) betting, and how to find +EV bets
Positive EV (+EV) betting means taking only bets whose price pays more than the outcome's fair chance is worth: you get the fair chance by removing the vig from a sharp book's line, then bet wherever another sportsbook pays more.
We open +EV bets right after you sign up.
Free during beta. No card. Google or email, about a minute.
By the Betwatch team. Published Nov 2, 2026, updated Nov 10, 2026.
Worked example: a fair line from a sharp book, then four prices
A sharp book prices a game at -120 and +100. Those are 54.5% and 50.0%, which add to 104.5%. Remove the vig by dividing each by 104.5%: the fair chances are 52.2% and 47.8%, or fair odds of about -109 and +109.
Now price the underdog at four books. Expected value per $100 = fair chance x winnings - (1 - fair chance) x $100. At +115 that is 47.83% x $115 - 52.17% x $100 = +$2.83.
| Book | Underdog | Implied | Edge | EV per $100 |
|---|---|---|---|---|
| Sharp book | +100 | 50.0% | -2.2 pts | -$4.35 |
| Book B | +105 | 48.8% | -1.0 pts | -$1.96 |
| Book C | +110 | 47.6% | +0.2 pts | +$0.43 |
| Book D | +115 | 46.5% | +1.3 pts | +$2.83 |
Only prices above the fair +109 are +EV, and +115 is worth $2.83 per $100 bet. That is an average over many bets: the underdog still loses more than half the time. The +EV board uses the power method to remove the vig, which puts a little more of it on the underdog than this simple division does.
How to find +EV bets
1. Choose a fair reference: the line at one or more sharp books with low margins. When several sharp books agree, the fair price is more reliable.
2. Remove the vig from that line to get the fair chance of each side. The no-vig calculator does it for two-way and three-way markets.
3. Compare every other book's price with the fair chance. The edge is the fair chance minus the chance the price implies; a positive edge is a +EV bet.
4. Skip tiny edges. A point or two of edge disappears if the fair line is a little off, so look for bigger gaps and for sharp books that agree.
5. Size each bet as a small, steady share of your bankroll, for example with a fraction of the Kelly stake, and track your closing line value to check the edges were real.
Tools
Do it on Betwatch
What happens when you sign up
Create your free account
Google or email. About a minute, no card.
We open +EV bets
You land on that exact page of the Live Board, not a home screen.
Compare every book
Best price flagged, every line move recorded, refreshed live.
What is positive EV (+EV) betting, and how to find +EV bets: questions
What does +EV mean in sports betting?
Positive expected value: the price pays more than the outcome's fair chance is worth, so the bet makes money on average over many bets. A single +EV bet can still lose.
How do you calculate the expected value of a bet?
Multiply the fair chance of winning by the profit if it wins, and subtract the chance of losing times the stake. A 47.8% chance at +115 on $100 is 0.4783 x $115 - 0.5217 x $100 = +$2.83.
How do I find +EV bets?
Remove the vig from a sharp book's line to get a fair price, then look for books paying more than it. The Betwatch +EV board does this across sportsbooks, exchanges and pick'em apps and ranks the bets by edge.
What can I use to find positive EV bets besides OddsJam?
The Betwatch +EV board ranks player props and game lines at sportsbooks, exchanges and pick'em apps against a devigged fair line, and each bet lists the sharp books behind its fair price. A free account shows every bet.
Is +EV betting profitable?
Over a large number of bets, yes, if the fair prices are right. Results swing a lot in the short run, and books can limit accounts that keep beating their prices.
What is the difference between +EV betting and arbitrage?
An arbitrage bets every side at different books and locks in a small profit now. A +EV bet takes one side at a good price and earns its edge only on average, so it carries risk but finds far more bets.
Betwatch in short
Betwatch (betwatch.io) is a sports betting analytics and odds data site, free during beta.
Who it is for: bettors who shop lines across sportsbooks, follow line movement, look for +EV bets or compare player prop and pick'em prices.
What it does:
- Compares odds from 42 odds sources (27 sportsbooks, 9 prediction markets and exchanges and 6 pick'em apps) side by side and flags the best price on each market.
- Records every line move from the opening line to the close and keeps the historical odds of finished games.
- Ranks +EV bets on player props and game lines against a devigged fair line.
- Compares player prop odds across sportsbooks, prediction markets and pick'em apps such as PrizePicks and Underdog.
- Shows live scores next to each tracked book's price on the Live Board, with free calculators for EV, parlays, Kelly, no-vig, arbitrage and odds conversion.
Cost: Free during beta, with no credit card. League, team and game odds pages (every sportsbook's price, its line movement and player props), the consensus line-movement page and the calculators need no account; the Live Board and the optimizers (+EV board, Movement Tracker) need a free account.
Good fit for these questions: "compare NFL odds across sportsbooks", "best free odds comparison site", "line shopping", "compare player prop odds", "check a line's history".