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What Is No-Vig Probability?
No-vig probability normalizes the implied probabilities of a complete market so they sum to 100%. It is a transparent estimate of fair market shares, not a guarantee of true outcome probability.
Start with a complete market
A two-way no-vig calculation needs both opposing prices from the same market and moment. For a moneyline without a draw, that means both teams. For a spread or total, the prices should correspond to opposite sides of the same point.
Combining a current price on one side with an older or differently lined price on the other creates a synthetic market that never existed. PickProof public tools ask for both prices and leave responsibility for matching them with the user.
Multiplicative normalization
PickProof converts each American price to implied probability, adds the probabilities, and divides each side by that total. If -110 and -110 each imply 52.38%, their combined 104.76% implies 4.76 percentage points of hold. Dividing each side by 104.76% produces 50.00% for each side.
This multiplicative method preserves each side's proportional share of the quoted market. It is easy to reproduce and is disclosed directly on the calculator.
Why no-vig is still an estimate
Different vig-removal methods can produce different fair probabilities, especially when the two prices are asymmetric. Multiplicative normalization does not claim to identify the sportsbook's internal model or the true probability.
Whole-number spreads and totals can push. A two-price normalization does not separately estimate the chance of landing exactly on the number, so it should not be treated as a full push-aware CLV model.
Example: -120 and +100
-120 implies 54.55%, while +100 implies 50.00%. Their sum is 104.55%, representing 4.55 percentage points above 100%. Multiplicative normalization produces approximately 52.17% and 47.83%.
Those values describe the proportional no-vig shares of that entered two-way market. They do not prove either outcome will occur.
Common mistakes
- Entering prices from different lines, books, or times.
- Using only one side and labeling its implied probability no-vig.
- Applying a two-way formula to a three-way market.
- Ignoring push probability on whole-number spreads or totals.
Important limitations
- Multiplicative normalization is one transparent method among several.
- The output depends entirely on the accuracy and compatibility of the entered prices.
- It does not estimate an outcome from team or player data.
- It is not a complete spread or total CLV model.
Frequently asked questions
Which method does PickProof use?
The public calculator uses multiplicative normalization of the entered implied probabilities.
Does no-vig remove every source of uncertainty?
No. It removes the quoted overround under one method; it does not create certainty.
Can no-vig probability be used for a three-way market?
Not with the two-way calculator. Every possible outcome must be included in the normalization.
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PickProof Learn content is for informational recordkeeping and analytics education. It does not place picks, accept funds, provide individualized advice, or guarantee performance. Odds, scores, grading, closing lines, and calculated metrics may be delayed, corrected, incomplete, or unavailable.