What "earned run average" means in baseball

Earned run average (ERA) is a statistic used in baseball to measure the effectiveness of a pitcher. It is calculated by taking the total number of earned runs the pitcher allows, multiplying it by nine, and then dividing it by the number of innings pitched. The lower the ERA, the better the pitcher is performing. It is a crucial statistic in evaluating a pitcher's performance and is often used as a factor in determining the winner of the Cy Young Award, considered the highest honor for pitchers in Major League Baseball.