Ed Walsh has the lowest career ERA among MLB pitchers with at least 1,000 innings pitched, finishing with a remarkable 1.82 mark. Walsh produced that figure during a career that ran from 1904 through 1917, primarily with the Chicago White Sox, and it remains one of baseball’s most durable statistical records.
Walsh was a right-handed spitball specialist whose best seasons came during the Dead-ball Era, when pitchers generally had a major advantage over hitters. In 1908, he posted a 1.42 ERA across 464 innings, led the American League in strikeouts, and won 40 games. His workload was extraordinary by modern standards: he threw 464 innings that year and completed 42 of his 49 starts.
Comparisons with modern pitchers require caution because baseball conditions have changed. The spitball was legal for established users like Walsh, ball composition was different, and starting pitchers routinely worked far more innings. Even so, the 1,000-inning minimum prevents short-career statistical flukes from dominating the list. Walter Johnson, Christy Mathewson, and Addie Joss were outstanding pitchers, but none finished with a lower qualifying career ERA than Walsh.