What is Parlay?
A single bet that combines two or more legs into one ticket — all legs must win for the parlay to pay.
Parlays multiply the decimal odds of every leg together, so two −110 legs (1.91 × 1.91 = 3.65) pay roughly +265 instead of +91 on either leg alone. The price the book gives is almost always worse than the true compound — that gap is the parlay vig. Parlays are great content (and good content marketing for picks services) but mathematically demanding, because adding legs makes hit probability fall faster than the price grows.
Example
Three −110 legs: 1.91 × 1.91 × 1.91 ≈ 6.96 decimal, or roughly +596 American. A $100 stake pays $696 on a hit.
Related terms
A bet on a specific event inside a game — most often a player stat over/under, but also team props or game props.
Expected value (EV) is the average profit or loss a bet pays per dollar staked if you repeated it under the same odds and probability forever.
A bet that combines several legs into multiple smaller parlays — every possible 2-leg or 3-leg combination — instead of one big parlay.
See parlay applied to a real slate
NotaSportsGuru runs the math behind every published leg — Parlay of the Day, player props, match lines — with the model’s expected value and edge on every line.