Novus Odds
 
LabsAdvanced· 7 min read· 4 steps

Compare de-vig methods in Model Comparison

See how proportional, power, Shin, odds-ratio, and additive margin removal produce different fair lines from the same prices.

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  1. 1

    Why de-vig matters

    Bookmaker prices include an overround so implied probabilities sum above 100%. Removing that margin estimates the fair line — but there is no single correct method.

  2. 2

    Contrast the methods

    Proportional scales every probability equally; power and Shin shift weight toward or away from longshots; odds-ratio and additive make different structural assumptions.

  3. 3

    Read the resulting fair lines

    Compare the fair probability each method assigns to the same selection. The spread between methods is model uncertainty you should not ignore.

  4. 4

    Tie it back to edge

    Your measured edge depends on which fair line you trust. A 'sure' edge under one method can vanish under another.

Key takeaways

  • There is no single correct de-vig method.
  • Method choice moves longshot probabilities the most.
  • Edge estimates inherit de-vig model uncertainty.
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Responsible use: these tutorials teach probability mathematics with synthetic data. They do not identify real-world profitable selections. Read the responsible-use page.