Bookmaker odds are skewed. They include a “Margin” (or Vigorish) that ensures the house wins. For example, if two teams have an equal chance of winning, the odds should be 2.00 / 2.00. Instead, you see 1.90 / 1.90.
This calculator removes the vigorish to show you the “True Odds” and the actual probability implied by the market. This is essential for comparing lines against your own models.
[gc_fair_odds]
Why Remove the Vig?
Professional bettors don’t beat the bookmaker’s displayed odds; they beat the Fair Odds. If you don’t know the true market price without the fee, you can’t accurately calculate your edge.
Example: Finding True Probability
Market: NFL Spread. Odds: -110 / -110 (Decimal: 1.91 / 1.91).
- Implied Probability (with Vig): 52.3% each. Total = 104.6%.
- Fair Probability (No Vig): 50% each.
- Fair Odds: +100 (2.00).
This tool tells you that to break even on this bet, you don’t need to win 52.3% of the time (as the raw odds suggest); you are playing a 50/50 proposition where you pay a fee to enter.
Frequently Asked Questions (FAQ)
What is “Vig”?
Vig (short for Vigorish), also known as Juice or Margin, is the commission charged by a sportsbook for taking a bet. It is built directly into the odds.