Implied Probability Decoder

Overview

This pillar converts betting odds and market prices into their true implied probabilities by removing the built-in house edge or vigorish. It provides a clear, unbiased view of what the market actually thinks will happen.

What It Does

It ingests odds from various outcomes within a single market, calculates the total implied probability which often exceeds 100 percent, and then normalizes these figures. This process strips away the bookmaker's margin, known as vigorish or 'vig'. The final output is a set of probabilities that accurately sum to 100 percent.

Why It Matters

Trading based on raw odds means you are fighting an inherent disadvantage. By understanding the true vig-free probability, you can accurately compare the market's forecast to your own analysis and identify genuine value opportunities.

How It Works

First, the pillar converts the odds for each outcome into individual probabilities. Second, it sums these probabilities to calculate the total market overround, which represents the bookmaker's margin. Finally, it divides each individual probability by this total sum to produce a normalized, vig-free probability for every outcome.

Methodology

The primary calculation uses the multiplicative normalization method. True Probability = (Individual Implied Probability) / (Sum of All Implied Probabilities). Individual probabilities are derived from American, decimal, or fractional odds before this normalization step is applied.

Edge & Advantage

It allows you to spot mispriced assets where your own probability assessment is higher than the market's true, margin-free probability, which is the core of value betting.

Key Indicators

• Vig-Free Probability

  high

  The normalized probability of an outcome after removing the bookmaker's margin.

• Bookmaker Margin

  medium

  The percentage over 100 that the raw implied probabilities sum to, representing the house edge.

• Market Consensus

  medium

  The collective probability assessment of the market, adjusted for built-in fees.

Data Sources

• Prediction Market APIs

  Provides real-time contract prices from platforms like Polymarket or Kalshi.

• Sportsbook Odds Aggregators

  Compiles betting lines and odds from multiple sportsbooks for comparison.

Example Questions This Pillar Answers

• → What is the true probability of the Kansas City Chiefs winning the Super Bowl based on current odds?
• → After removing the market's fee, will the next Fed rate decision be a hike or a hold?
• → Will a specific film win the Oscar for Best Picture, according to the vig-free consensus?

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