2009 AL Earned Run Average by Team

The Seattle Mariners led the AL in earned run average in 2009, with 3.87, 0.29 ahead of the Chicago White Sox. The average across 14 AL teams is 4.47.

Led the AL in 2009 Seattle Mariners 162 games

3.87 Earned Run Average 0.29 clear of Chicago White Sox

#	Team	G	ERA
1	Seattle Mariners	162	3.87
2	Chicago White Sox	162	4.16
3	New York Yankees	162	4.28
4	Oakland Athletics	162	4.29
5	Detroit Tigers	163	4.34
6	Boston Red Sox	162	4.35
7	Tampa Bay Rays	162	4.36
8	Texas Rangers	162	4.38
9	Los Angeles Angels of Anaheim	162	4.45
	AL average		4.47
10	Toronto Blue Jays	162	4.47
11	Minnesota Twins	163	4.50
12	Kansas City Royals	162	4.83
13	Cleveland Indians	162	5.07
14	Baltimore Orioles	162	5.16

A team's total is its players' numbers for the club added up, so a player traded mid-season counts for each team only what he did there. Rates such as ERA and batting average are worked out from the team's summed totals, not averaged across players.