1. What is the ELO Win Probability?

The ELO win probability formula estimates the expected outcome between two teams based on their ELO ratings. It's widely used in basketball analytics to predict game outcomes and assess team strength.

2. How Does the Calculator Work?

The calculator uses the ELO probability equation:

Where:

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

Explanation: The equation converts the rating difference between two teams into a win probability, with 400 rating points equating to a 10:1 expected win ratio.

3. Importance of ELO Ratings

Details: ELO ratings provide a dynamic measure of team strength that updates after each game based on performance relative to expectations. Higher ratings indicate stronger teams.

4. Using the Calculator

Tips: Enter both teams' current ELO ratings. The calculator will show your team's probability of winning. Typical NBA ELO ratings range from 1300 (weak teams) to 1800 (elite teams).

5. Frequently Asked Questions (FAQ)

Q1: What's a typical ELO rating difference in NBA games?
A: Most regular season games feature teams within 200 points of each other (60%-40% win probability). Playoff matchups are often closer.

Q2: How accurate is the ELO prediction?
A: For established teams with stable ratings, predictions are typically within 3-5% of actual outcomes over large samples.

Q3: Why is the constant 400 used?
A: This scaling factor determines how quickly probabilities change with rating differences. 400 means a 400-point better team is 10x more likely to win.

Q4: Can this be used for other sports?
A: Yes, but the scaling factor (400) may vary. Chess uses 400, while other sports may use different values based on typical upsets.

Q5: How do teams gain or lose ELO points?
A: Teams gain more points for beating stronger opponents and lose more points when losing to weaker opponents than expected.