Seattle Mariners ERA Charts and Records
About ERA
Earned run average (ERA) is a metric that shows how many earned runs on average, a pitcher or team's pitcher, gives up over the course of nine innings. It is calculated by dividing earned runs by innings pitched then multiplying the result by 9. Generally, for ERA, lower is better. (Source)
Top Seattle Mariners Players by ERA
Which Seattle Mariners players rank highest in ERA? Below are the top ten by single season and by career totals with the team, requiring at least 50 innings pitched for a season record, or 100 innings pitched for a career record with the team.


Seattle Mariners ERA Per Season
Seattle Mariners's ERA for each season of their history, plotted alongside yearly averages for MLB, the American League, and the American League West.

Seattle Mariners ERA Season Distribution vs. MLB and Peers
Each box summarizes ERA across all seasons, comparing the Seattle Mariners to MLB as a whole, the American League, and the American League West. The box covers the middle 50% of seasons, the center line is the median, and the whiskers extend to the min and max values.

Seattle Mariners ERA Year-Over-Year Change
A waterfall chart showing how the Seattle Mariners's ERA shifted season over season. Each bar represents the change from the previous year, making it easy to spot peak and decline phases.

Seattle Mariners ERA — Season-by-Season Breakdown
Every season of Seattle Mariners's history with ERA alongside yearly averages for MLB, the American League, and the American League West. Career totals include sum, average, minimum, maximum, and median.
