Parlay
A combined bet whose odds are the product of each selection's odds, and which loses if any single selection loses.
A parlay (an accumulator, or acca, in the UK and much of Europe) joins several selections into one stake. With decimal odds, the combined price is the product of the legs. Push or void legs normally fall out at 1.00 (see void bet).
Payout example
Four soccer selections at 1.50, 1.70, 1.90 and 2.00.
Combined: 1.50 × 1.70 × 1.90 × 2.00 = 9.69. A €10 stake returns €96.90.
How the margin compounds
Assume each leg pays 95% of its fair price (a 5% margin per selection). The expected return of the parlay is the product of the per-leg returns:
| Legs | Expected return |
|---|---|
| 1 | 95.0% |
| 2 | 90.3% |
| 4 | 81.5% |
| 8 | 66.3% |
So the effective house edge on an eight-leg ticket is roughly 34%, against 5% on a single. This is why sportsbooks promote parlays heavily.
Correlation
The multiplication only holds when the legs are independent. Selections from the same match are linked, which is why books price them separately as a same-game parlay or bet builder.
When parlays make sense
If you genuinely have an edge on each leg, compounding works in your favour too. Without one, each additional leg adds margin.