| Team/Year | ERA Champion | Earned Run Average |
| New York Yankees, 1980 | |
| Los Angeles Dodgers, 1980 | |
| New York Yankees, 1981 | |
| Houston Astros, 1981 | |
| Cleveland Indians, 1982 | |
| Montreal Expos, 1982 | |
| Texas Rangers, 1983 | |
| San Francisco Giants, 1983 | |
| Baltimore Orioles, 1984 | |
| Los Angeles Dodgers, 1984 | |
| Toronto Blue Jays, 1985 | |
| New York Mets, 1985 | |
| Boston Red Sox, 1986 | |
| Houston Astros, 1986 | |
| Toronto Blue Jays, 1987 | |
| Houston Astros, 1987 | |
| Minnesota Twins, 1988 | |
| St. Louis Cardinals, 1988 | |
| Kansas City Royals, 1989 | |
| San Francisco Giants, 1989 | |
| Boston Red Sox, 1990 | |
| | Team/Year | ERA Champion | Earned Run Average |
| Houston Astros, 1990 | |
| Boston Red Sox, 1991 | |
| Montreal Expos, 1991 | |
| Boston Red Sox, 1992 | |
| San Francisco Giants, 1992 | |
| Kansas City Royals, 1993 | |
| Atlanta Braves, 1993 | |
| Oakland Athletics, 1994 | |
| Atlanta Braves, 1994 | |
| Seattle Mariners, 1995 | |
| Atlanta Braves, 1995 | |
| Toronto Blue Jays, 1996 | |
| Florida Marlins, 1996 | |
| Toronto Blue Jays, 1997 | |
| Montreal Expos, 1997 | |
| Toronto Blue Jays, 1998 | |
| Atlanta Braves, 1998 | |
| Boston Red Sox, 1999 | |
| Arizona Diamondbacks, 1999 | |
| Boston Red Sox, 2000 | |
| Los Angeles Dodgers, 2000 | |
| | Team/Year | ERA Champion | Earned Run Average |
| Seattle Mariners, 2001 | |
| Arizona Diamondbacks, 2001 | |
| Boston Red Sox, 2002 | |
| Arizona Diamondbacks, 2002 | |
| Boston Red Sox, 2003 | |
| San Francisco Giants, 2003 | |
| Minnesota Twins, 2004 | |
| San Diego Padres, 2004 | |
| Cleveland Indians, 2005 | |
| Houston Astros, 2005 | |
| Minnesota Twins, 2006 | |
| Houston Astros, 2006 | |
| Los Angeles Angels of Anaheim, 2007 | |
| San Diego Padres, 2007 | |
| Cleveland Indians, 2008 | |
| New York Mets, 2008 | |
| Kansas City Royals, 2009 | |
| St. Louis Cardinals, 2009 | |
| Seattle Mariners, 2010 | |
| Florida Marlins, 2010 | |
|