1. What is ELO Win Probability?

The ELO win probability formula estimates the chance that one team will win against another based on their ELO ratings. Originally developed for chess, it's now widely used in baseball and other sports for predictive analysis.

2. How Does the Calculator Work?

The calculator uses the ELO probability formula:

Where:

• \( P \) — Win probability (0 to 1)
• \( R \) — Your team's ELO rating
• \( R_{opp} \) — Opponent's ELO rating

Explanation: The formula calculates the expected outcome between two teams based on their relative skill levels as measured by ELO ratings. A 400-point difference corresponds to a 10:1 expected score ratio.

3. Importance of ELO Ratings

Details: ELO ratings provide a quantitative measure of team strength that adjusts after each game based on performance against expectations. In baseball, they're used for predictions, betting lines, and team comparisons.

4. Using the Calculator

Tips: Enter both teams' current ELO ratings. The calculator will show the probability that the first team (with rating R) will win against the opponent (with rating R_opp).

5. Frequently Asked Questions (FAQ)

Q1: What's a typical ELO range in baseball?
A: MLB teams typically range between 1400-1600, with elite teams reaching 1700+ and poor teams dropping below 1300.

Q2: How accurate is this probability estimate?
A: Over large samples, ELO predictions are reasonably accurate, but individual games have high variability due to baseball's inherent randomness.

Q3: What does a 100-point ELO difference mean?
A: A 100-point advantage corresponds to about a 64% win probability (or 64% chance to win a neutral game).

Q4: How often are ELO ratings updated?
A: Most systems update after each game, with adjustments based on game outcome versus expectation.

Q5: Does this account for home field advantage?
A: Basic ELO doesn't, but advanced implementations typically add 30-50 points for the home team.