Expected ERA vs Actual ERA Part II

Expected ERA vs Actual ERA Part II

Thursday we looked at the pitchers from 2007 who benefited from an ERA which was better "than deserved". This sabermetric formula is based on a statistic developed by researchers Dwight Gill and Tad Reeve.

Expected ERA (XERA) depicts a pitcher’s "True ERA" based on factors within a pitcher's control. These factors include Hits, Walks, Home Runs allowed and K’s. When you consider the inequity with the ERA calculation, specifically related to errors and base runners inherited/left, many including myself consider XERA to be a more precise gauge of ability. The formula as follows: ((.575 * H/9 ) + (.94 * HR/9 ) + (.28 * BB/9 ) - (.01 * K/9 ) - Normalizing Factor). The normalizing factor is based on the league (typically in the .270 and .285 range)

Below is a listing of pitchers who had a higher than expected ERA in 2007. Naturally these are also candidates to post better ERA numbers in 2008.

Chris Young's '08 campaign not only saw him shorted in Wins but also ERA. Young posted an ERA of 3.12 but according to the xERA formula it should have been closer to 2.21. Young is a great value heading into '08, he's #9 on our board in a typical 5x5.

Dustin McGowan is a rising young stud pitcher. His GB ratio of 64% and .88 K/I % are a great combination. Although his low BHIP% overvalued his WHIP, his xERA was 87 points less than his actual.

Tim Lincecum was shorted 5 Wins according to our Expected Wins indicator in '07, additionally his ERA may have been overstated by 67 points.

Wandy Rodriguez K/I rate has improved, which is improving his runners stranded rate. Drop in ERA expected as his ERA may have been overstated by 48 points last year.

Barry Zito Bounceback season projected in both Wins & ERA. xERA in '07 was 48 more than deserved.

Matt Cain  xWins pins him at 16 Wins in '07, instead of 9. xERA shows his ERA expectation should have been over 40 points lower. Undervalued!