+EV (positive expected value) betting means placing bets whose price is better than the true odds — so you profit over the long run, even though any single bet can lose.
Expected value (EV) is the average result of a bet if you could place it thousands of times. A bet is +EV when the price you get implies a lower probability than the outcome's true probability — i.e. the sportsbook is paying you more than the risk is worth. Do that consistently and math, not luck, carries you to profit.
EV% = (your decimal odds × true win probability) − 1. The hard part is estimating the true probability. The standard approach is to take the no-vig fair line — the market's consensus with the sportsbook margin removed — as the best cheap estimate of true odds.
Over a large sample, yes — if your fair-line estimates are accurate. Any single bet or even a bad week can lose; the edge only shows over volume.
Compare each book's price to a no-vig consensus fair line and bet anything priced meaningfully above it. Tools automate this across many books — that's what our engine and live board do.