Glossary

What is vig in sports betting?

Last updated 2026-07-04

Vig, short for vigorish and also called juice, is the bookmaker's built-in margin. The implied probabilities of all outcomes in a market sum to more than 100%; the excess is the vig. At the standard -110 both ways, the market implies 104.8%, so the vig is 4.8%.

Vig is why breaking even on picks loses money. At -110 you must win 52.38% of your bets just to break even, while a coin flip wins 50%. The 2.38% gap is the book's edge on every wager, collected win or lose over volume.

Vig varies by book and market. Sharp books run 2-3% on main lines; retail books run 4-5% on mainlines and much more on props and parlays. Removing the vig from a market recovers the book's true probability estimate, which is the basis of fair odds and every serious +EV workflow.

Compute it for any market with the no-vig calculator: enter every side, read the hold percentage.

Compute it with the API

curl "https://api.theoddsapi.com/intelligence/market-analysis?sport_key=basketball_nba" \
  -H "x-api-key: YOUR_API_KEY"

The market-analysis endpoint returns per-event hold percentages and which book is tightest, precomputed across the whole slate. Business tier. Free key in minutes.