How Parlay Betting Works
A parlay (also called an accumulator or multi-bet) combines 2 or more selections into a single bet. All legs must win for the bet to pay out. The odds multiply together, creating potentially large payouts from small stakes — at the cost of much lower probability.
The House Edge on Parlays
Because each leg carries the bookmaker's margin, parlays amplify this margin. A 2-leg parlay roughly doubles the house edge; a 10-leg parlay can have a house edge exceeding 30%. This calculator shows you the true implied probability so you can see exactly what you're up against.
When Parlays Make Sense
Parlays are positive-EV when you have a genuine edge on each leg AND each leg is independent (different sports, different books). Correlation between legs (e.g., same game player props) can be exploited, but bookmakers are increasingly restricting correlated parlays.