How Parlay Odds Are Calculated
A parlay combines multiple individual bets into one ticket. To win, every single leg must win. The combined payout is calculated by multiplying the decimal odds of each leg together:
Example — 3-Team Parlay
Leg 1: -110 (decimal 1.909) | Leg 2: +150 (decimal 2.50) | Leg 3: -120 (decimal 1.833)
Parlay decimal: 1.909 × 2.50 × 1.833 = 8.75
On $100 stake: Total payout $875 | Profit $775
Implied win prob: 1/8.75 = 11.43%
The Real Cost of Parlays
Parlays are extremely profitable for sportsbooks because the vig compounds on every leg. A 3-leg parlay built with -110 legs has a true win probability of ~12.5%, but the payout implies a lower probability after all three books take their cut.
The fair payout for a 3-leg -110 parlay is approximately +595. Most books pay around +595 for this exact parlay — which sounds fair, but the true value after removing vig from each leg suggests the fair parlay odds should be even higher.
When Parlays Make Sense
Parlays are +EV only when you're building them from individual +EV legs. If every leg has positive expected value on its own, combining them preserves that edge. "Correlation parlays" — where outcomes are linked (e.g., QB throws TDs + team wins) — can add further edge that books may misprice.
Build Parlays From Sibyl's +EV Picks
Every Sibyl pick comes with model probability and edge data — so you can identify when each leg truly has value before combining them.
See Plans & Pricing →