Parlay, in plain words
A parlay combines two or more bets into one ticket. Every leg has to win for the parlay to pay, and the payout is the product of the legs' decimal odds. That is why small stakes can return large amounts, and why parlays are so popular.
The catch is that the book's margin multiplies along with the payout. Each leg carries its own vig, so a two-leg parlay carries roughly twice the margin of one bet, and a six-leg parlay much more. The bigger the ticket, the bigger the share the book keeps.
A parlay can still be a good bet when its legs are each priced better than fair, or when the legs genuinely move together and the book has not priced that in. Without one of those, a parlay is a more expensive way to make the same bets.
The idea, drawn
Worked example · illustration
Two legs at −110
- Each leg
- −110 (1.909)
- Parlay pays
- +264
- Fair parlay
- +300
- Leg break-even
- 52.38%
- Decimal odds multiply: 1.9091 x 1.9091 = 3.6446, which is +264.
- With the margin out, each leg is a 50% chance, so both win 25% of the time: a fair price of +300.
- The ticket pays +264 for a +300 chance; the gap is two legs of margin stacked.
Each extra leg adds its own margin. Parlay legs you would bet on their own, at prices you would take on their own.