The expected value formula
EV equals (probability of winning times profit if you win) minus (probability of losing times amount risked). If your read says a team wins 55 percent of the time and the price pays even money (+100), a $100 bet has EV of (0.55 x $100) - (0.45 x $100) = +$10. Positive means the bet is worth making; negative means it is not.
How to find +EV bets
The practical method is to strip the book's margin out of the odds to get the fair, no-vig probability, then compare it to your own estimate or to a sharper book's price. When a book's implied probability is lower than the true probability, the difference is your edge. Line shopping across books surfaces these gaps constantly.
Why EV matters more than winning percentage
You can win most of your bets and still lose money by laying huge prices on favorites, and you can lose most bets and profit by consistently getting the best number on underdogs. Chasing +EV, not a high hit rate, is what compounds a bankroll. Every play on this site is framed around the number, not the outcome of one game.
Frequently asked questions
What does +EV mean?
Positive expected value: the bet is priced better than its true probability, so it profits over a large sample even though individual bets still lose sometimes.
Can a losing bet still be +EV?
Yes. EV is about the price versus the true odds, not any single result. A well-priced bet can lose and still have been the right bet to make.
Related terms
21+. For entertainment and educational purposes, not financial advice. If gambling stops being fun, take a break. 1-800-GAMBLER. Regulated US books only.