What "overlay" means
An overlay is a bet whose offered odds imply a probability lower than the true probability of the outcome. In other words, the bookmaker is paying you more than the risk deserves. That gap is your edge.
Expected value in one formula
EV = (p_true * (odds - 1)) - (1 - p_true)
If your estimated true probability is 55% and the odds are 2.00:
- EV = 0.55 * 1.00 - 0.45 = +0.10 per unit (a 10% edge).
Positive EV is the whole game. Everything else — bankroll, CLV, staking — is how you survive variance long enough to realize it.
Where overlays come from
- Slow-moving soft books
- Overreactions to public narratives
- Injury/lineup news the price hasn't absorbed yet
Find them, bet them, and track your CLV to confirm you were right.