ERA (Earned Run Average) Calculator

ERA Formula:

\[ ERA = \frac{Earned\ Runs \times 9}{Innings\ Pitched} \]

Earned Run Average (ERA):

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1. What is ERA in Baseball?

ERA (Earned Run Average) is a statistic that measures a pitcher's effectiveness, representing 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 in baseball.

2. How Does the ERA Calculator Work?

The calculator uses the standard ERA formula:

\[ ERA = \frac{Earned\ Runs \times 9}{Innings\ Pitched} \]

Where:

\( Earned\ Runs \) — Runs scored without benefit of errors
\( Innings\ Pitched \) — Total innings pitched (can include fractions like 6.2)
\( 9 \) — Standard number of innings in a regulation game

Explanation: The formula scales the earned runs to a standard 9-inning game, allowing comparison between pitchers regardless of how many innings they've pitched.

3. Importance of ERA Calculation

Details: ERA is crucial for evaluating pitcher performance, comparing pitchers across different games and seasons, and making strategic decisions about pitcher usage. Lower ERA values indicate better performance.

4. Using the Calculator

Tips: Enter total earned runs allowed (whole numbers or decimals) and total innings pitched (can include fractions like 5.1 for 5⅓ innings). Both values must be positive, with innings pitched > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's considered a good ERA?
A: In modern MLB, ERA below 4.00 is generally good, below 3.00 is excellent, and below 2.00 is outstanding. Standards vary by era and league.

Q2: How do you count partial innings?
A: 0.1 = ⅓ inning (1 out), 0.2 = ⅔ inning (2 outs). For example, 6.2 innings means 6 innings plus 2 outs.

Q3: What's the difference between ERA and WHIP?
A: ERA measures runs allowed, while WHIP (Walks + Hits per Inning Pitched) measures baserunners allowed. Both are important pitcher metrics.

Q4: Does ERA account for ballpark factors?
A: Standard ERA doesn't. Advanced metrics like ERA+ adjust for ballpark effects and league averages.

Q5: What's the lowest single-season ERA in MLB history?
A: The modern record is 1.12 by Dutch Leonard in 1914. Since 1969, the lowest is 1.53 by Dwight Gooden in 1985.