Novus Odds
 
SportsAdvanced· 7 min read· 4 steps

Read a horse field's four probabilities

Understand raw implied, margin-adjusted, underlying model, and observed frequency for every runner in a synthetic field.

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  1. 1

    Raw implied

    The break-even probability of each runner's price, before margin removal. Across the field these sum above 100% by the overround.

  2. 2

    Margin-adjusted

    The de-vigged fair probability. This is what the price implies once the bookmaker margin is stripped out.

  3. 3

    Underlying model

    The independent performance model's true win probability. Because pricing and performance models are separate, this need not match the price.

  4. 4

    Observed frequency

    How often the runner actually won across the simulated races. A well-calibrated model puts observed frequency near the underlying model.

Key takeaways

  • Pricing and performance models are independent by design.
  • Margin-adjusted strips the overround from the price.
  • Observed ≈ underlying signals good calibration.
Related breakdowns guide →All tutorials →
Responsible use: these tutorials teach probability mathematics with synthetic data. They do not identify real-world profitable selections. Read the responsible-use page.