Joba Chamberlain's ERA+ last season was 1192! That's ridiculous!
Are you wondering what the highest season ERA+ is for a pitcher with a minimum number of innings? Me, too. Let's visit our friend, BR.
First, though, an explanation: ERA+ is the ratio of the league's ERA, adjusted to the pitcher's ballpark, to that of the pitcher. 100 is league average. Top-shelf starters will finish their seasons with ERA+s around 140. Random career ERA+s as of right now: Brandon Webb 142, Johan Santana 141, Roy Oswalt 137, Greg Maddux 133, Jake Peavy 121, Barry Zito 117, Josh Beckett 116.
Joba threw 24 innings in 2007 (facing 91 batters), and if we use that as a cut-off, Chamberlain is the clear winner. (Anyone else find the heading of the first column amusing with regard to JtC?).
For pitchers with a full season, Dennis Eckersley's 1990 season is tops (606 ERA+ in 73.1 IP). Jonathan Papelbon's 2006 season (515 ERA+) is 10th-best all-time.
Almost all of the pitchers on the list are relievers, which makes sense, but check out the #2 guy: Buck O'Brien. He posted a 866 ERA+ as a 29-year-old rookie for the 1911 Red Sox. He pitched in six games -- five of them starts. In 47.2 innings, he allowed 30 hits and 21 walks, but had an ERA of only 0.38. How is that possible? Of the nine runs he allowed (a 1.70 RA), only two of them were earned.
Obligatory Pedro Note When Mentioning ERA+: Among pitchers who qualified for the ERA title, Pedro's unprecedented 2000 (291 ERA+ in 217 innings) reigns supreme. Pedro also has the 8th-, 17th-, 25th-, and 30th-best season all-time. Note to media: Sandy Koufax's first appearance on the list is at #50. Stop comparing these two guys. Koufax was amazing, but Pedro was God.