Glossary

What are no-vig fair odds and how is de-vigging done?

Last updated 2026-07-04

No-vig fair odds are a market's prices with the bookmaker margin stripped out, recovering the book's true probability estimate. De-vigging divides each outcome's implied probability by the market total so probabilities sum to exactly 100%, then converts back to odds.

Worked example: a moneyline at -110 / -110 implies 52.38% + 52.38% = 104.76%. Dividing each by 1.0476 gives 50% / 50%, so the fair price is +100 each side and the 4.76% excess was the vig. A market at -150 / +130 devigs to 56.5% / 43.5%: fair odds of about -130 and +130.

Fair odds matter because they turn price comparison into value detection. If the devigged consensus says an outcome is 50% and a book offers +110 (47.6% implied), that bet is +EV. Every serious value-betting workflow reduces to comparing offered prices against a trustworthy fair number.

Proportional de-vigging is the standard method; alternatives (Shin, power) adjust for favorite-longshot bias at extreme prices. Run any market through the no-vig calculator, or read the value bets guide for the full workflow.

Compute it with the API

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

Precomputed vig-removed fair prices from a consensus of 30-50 books anchored on sharp ones, which beats devigging any single book. Business tier. Free key in minutes.