Parlay

A parlay combines two or more individual bets into a single wager. ALL selections (legs) must win for the parlay to pay. If even one leg loses, the entire parlay loses.

Because the legs multiply, parlays pay larger amounts than individual bets — but they also compound the vig from each leg, making most parlays significantly -EV.

Example: A 4-leg parlay of -110 bets (each ~52.4% raw implied) has true probability of (0.5)^4 ≈ 6.25% if each leg were 50/50, but pays at 12-1 odds (~7.7%). The math says you lose long-run.

There's exactly one scenario where parlays make sense: CORRELATED parlays where the legs are positively correlated and the book doesn't price the correlation correctly. Example: Same-game parlay of Lakers ML + Over total — if the Lakers are likely to win big, both legs tend to hit together. Sharp books now price correlations into same-game parlays, killing most of this edge.

SportsBookISH doesn't focus on parlays because they're a -EV product for most users. The bet tracker (Elite) records parlays you log but emphasizes single-bet skill score (CLV/ROI) over parlay results.