ERA (Earned Run Average)

The average number of earned runs a pitcher allows per nine innings — the foundational pitching statistic.

ERA is calculated by dividing earned runs allowed by innings pitched, then multiplying by 9. It is the most widely cited pitching statistic and the traditional benchmark for evaluating a pitcher's effectiveness.

ERA benchmarks (modern era, roughly adjusted for league): - Below 2.50: elite (Cy Young candidate) - 2.50–3.49: very good (above-average starter) - 3.50–4.24: average to slightly above - 4.25–5.00: below average - Above 5.00: replacement level

ERA has well-known limitations: it is sensitive to fielding quality, ballpark dimensions, and luck on balls in play. Modern analysts prefer FIP (Fielding Independent Pitching) or xFIP, which isolate outcomes a pitcher directly controls — strikeouts, walks, and home runs.

For Hall of Fame evaluation, ERA+ (park-adjusted ERA, where 100 = league average) is the standard. A career ERA+ above 120 is a strong HOF indicator for starting pitchers with sufficient innings.