Parlays combine multiple bets into one ticket where every leg must win. The payouts look spectacular, and that's precisely the point — parlays are the most profitable product sportsbooks sell, for them.
The Math Behind the Payout
Parlay odds multiply: three -110 legs pay about +596. But fair odds for three 52.4% events would be +616 — the book's edge compounds with every leg. Standard vig of ~4.5% per leg becomes roughly 13% on a three-leg parlay and over 30% on six legs.
Same-Game Parlays: Extra Caution
SGPs correlate legs (a QB's passing yards and his team winning), and books price that correlation in-house — usually conservatively in their favor. Boosted SGP promos can offset this, but unboosted SGPs typically carry the worst hold percentages on the entire site.
When a Parlay Is Defensible
Genuinely correlated legs the book underprices, promo boosts that push payouts past fair odds, and small entertainment stakes are the legitimate cases. As a bankroll strategy, flat single bets outperform parlays over any meaningful sample.
Frequently Asked Questions
What happens if one parlay leg pushes?
The leg is removed and the parlay recalculates at the remaining legs' odds — a 4-leg becomes a 3-leg. It does not lose.
Are parlays ever +EV?
Rarely: correlated legs mispriced by the book, or promo boosts. Run your numbers in our Parlay Calculator before assuming a boost creates value.