2012 MLB Earned Run Average by Team

The Tampa Bay Rays led all of MLB in earned run average in 2012, with 3.19, 0.15 ahead of the Cincinnati Reds. The average across 30 MLB teams is 4.02.

Led all of MLB in 2012 Tampa Bay Rays 162 games

3.19 Earned Run Average 0.15 clear of Cincinnati Reds

#	Team	League	G	ERA
1	Tampa Bay Rays	AL	162	3.19
2	Cincinnati Reds	NL	162	3.34
2	Washington Nationals	NL	162	3.34
4	Los Angeles Dodgers	NL	162	3.35
5	Atlanta Braves	NL	162	3.42
6	Oakland Athletics	AL	162	3.50
7	San Francisco Giants	NL	162	3.68
8	St. Louis Cardinals	NL	162	3.71
9	Seattle Mariners	AL	162	3.76
10	Detroit Tigers	AL	162	3.77
11	New York Yankees	AL	162	3.85
12	Philadelphia Phillies	NL	162	3.86
13	Baltimore Orioles	AL	162	3.90
14	Pittsburgh Pirates	NL	162	3.91
15	Arizona Diamondbacks	NL	162	3.94
16	San Diego Padres	NL	162	4.01
	MLB average			4.02
17	Chicago White Sox	AL	162	4.02
17	Los Angeles Angels of Anaheim	AL	162	4.02
17	Texas Rangers	AL	162	4.02
20	New York Mets	NL	162	4.09
21	Miami Marlins	NL	162	4.10
22	Milwaukee Brewers	NL	162	4.22
23	Kansas City Royals	AL	162	4.30
24	Chicago Cubs	NL	162	4.51
25	Houston Astros	NL	162	4.57
26	Toronto Blue Jays	AL	162	4.64
27	Boston Red Sox	AL	162	4.72
28	Minnesota Twins	AL	162	4.77
29	Cleveland Indians	AL	162	4.79
30	Colorado Rockies	NL	162	5.22

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.