Parlays
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Combining Multiple Bets Into One Ticket
A parlay combines two or more individual bets onto a single ticket. For the parlay to win, every leg must win. If any single leg loses, the entire parlay loses — there are no partial payouts.
The trade-off is a larger potential payout in exchange for a much lower probability of winning. Books love parlays because the house edge compounds with each additional leg.
How Parlay Odds Are Calculated
In theory, parlay odds are the product of each leg's decimal odds. In practice, books apply their own parlay calculation that gives you slightly less than true multiplication.
Example: 2-leg parlay
Leg 1: Chiefs −110 (decimal 1.91)
Leg 2: Over 47.5 −110 (decimal 1.91)
True combined decimal: 1.91 × 1.91 ≈ 3.65 → roughly +265
Most books offer around +260 on this parlay — slightly below the true multiplied odds.
That gap between the true payout and what the book offers is the compounded vig. On a 4-leg parlay, the gap is much wider.
Why Parlays Are Usually Bad Value
Each leg of a parlay carries the book's built-in margin. Combining legs multiplies the margin rather than spreading it. Here is what that looks like across parlay sizes at standard −110 pricing:
| Legs | True win prob. | Book's effective margin |
|---|---|---|
| 1 | 47.6% | 4.5% |
| 2 | 22.6% | ≈ 8.6% |
| 3 | 10.8% | ≈ 12.4% |
| 4 | 5.1% | ≈ 15.9% |
Each additional leg roughly doubles the difficulty of winning while the book's take grows with it. Parlays are entertainment, not a path to long-run profit.
When Parlays Show Up in Promos
Sportsbooks do run parlay-specific promos, and some of them create genuine value:
- Parlay insurance. A refund in bonus bets if exactly one leg of a multi-leg parlay loses. The insurance creates a floor that can be converted via matched betting.
- Parlay boosts. A percentage added to your parlay payout. Works like a profit boost — extra value you can lock in by hedging.
- Stepped-up parlay bonuses. Bonus bets unlocked for hitting a parlay of N+ legs. The value is in the bonus, not the parlay itself.
In all of these cases, the promo value — not the parlay itself — is what you're converting. Read the terms carefully; many require specific minimum odds per leg or exclude certain markets.