1. What is Earned Run Average (ERA)?

ERA (Earned Run Average) is a statistic in baseball that represents the average number of earned runs a pitcher allows per nine innings pitched. It's one of the most important metrics for evaluating pitcher performance.

2. How Does the Calculator Work?

The calculator uses the ERA formula:

Where:

• Earned Runs — Runs scored without the benefit of errors
• Innings Pitched — Number of innings the pitcher has thrown
• 9 — Standard number of innings in a complete game

Explanation: The formula calculates how many runs a pitcher would allow over a full nine-inning game based on their current performance.

3. Importance of ERA Calculation

Details: ERA is crucial for evaluating pitcher effectiveness, comparing performance across different pitchers, and making strategic decisions about pitching rotations and bullpen usage.

4. Using the Calculator

Tips: Enter the number of earned runs allowed and innings pitched. Innings can be entered as decimals (e.g., 6.2 for 6⅔ innings). Both values must be valid (innings > 0, earned runs ≥ 0).

5. Frequently Asked Questions (FAQ)

Q1: What's considered a good ERA?
A: In modern baseball, an ERA below 4.00 is generally good, below 3.00 is excellent, and below 2.00 is exceptional.

Q2: How does ERA differ from other pitching statistics?
A: Unlike WHIP (walks+hits per inning) or FIP (fielding independent pitching), ERA directly measures runs allowed, making it a comprehensive measure of run prevention.

Q3: Are unearned runs included in ERA?
A: No, ERA only includes earned runs - those scored without defensive errors contributing to the scoring play.

Q4: Why multiply by 9 in the formula?
A: Multiplying by 9 standardizes the statistic to a full game, allowing comparison between pitchers regardless of how many innings they've pitched.

Q5: Does ERA account for ballpark factors?
A: No, basic ERA doesn't account for ballpark effects. For more accurate comparisons, statisticians sometimes use ERA+ which adjusts for ballpark and league factors.