Rays Alumni: The Roller Coaster Ride of Edwin Jackson

During last offseason the Rays traded two potential 2009 starting pitchers in Edwin Jackson and Jason Hammel.  A member of the rotation in 2008, Edwin Jackson was moved to the Detroit Tigers in exchange for outfielder Matt Joyce.  Jackson had won 14 games last season as the Rays fifth starter and was about to get more expensive.  Despite the impressive win total and 4.42 ERA, the Rays had grown tired of Jackson's lack of progress. He struck out a career low 5.3 per 9 innings while walking 3.78. In short, it seemed Jackson was a decent pitcher whose traditional stats were inflated by the American League's top defense according to UZR.  The Rays had an abundance of starting pitching and thought the cost controlled 25-year-old Joyce could be the long term answer in right field.

In 2009 Jackson made the American League All-Star team as a member of the Tigers. He pitched the first half of the season like a bona fide Cy Young candidate, sporting a 2.52 ERA and 3.19 FIP which sent Rays fans up in arms given their team's early struggles.  Very quietly things came undone in the second half where Edwin compiled an unflattering ERA/FIP of 5.07/5.33.  Please see below for a comparison of 2008 and 2009, along with first and second half splits.

Jackson's fielding independent numbers did show improvement over 2008 in both halves of the season. However, you can see a big change between the two halves in both strikeouts and walks.  His home run rate year over year remained constant despite .5 HR/9 during the first half of the season.  This site frequently discussed the lack of sustainability of that number and true-to-form regression made Edwin pay a steep price.  Jackson has had a bit of home run luck each of the past two seasons, as evidenced by his xFIP, which normalizes home run rates as 10% of fly balls.  Finally, the unsustainable .249 BABIP of the first half snapped back to reality.

For all the talk of his improved slider there is little indication of increased success. The pitch was thrown more frequently this season, with usage increasing from 21.8% in 2008 to 27.4% in 2009. However, the wSL/C, which is the runs above average per 100 pitches for the slider, actually decreased from 2.87 to 1.89 from year to year. Despite the walk and strikeout improvements, Jackson threw more pitches out of the zone in 2009. He benefitted from batters chasing a much higher percentage of his pitches in 2009, as his O-Swing% went from 21.7% to 27.2% which probably helps to account for the increase in his swinging strike % (7.7% to 9.8%). It will be interesting to see how close Jackson can come to replicating that in 2010.

Edwin Jackson is a good pitcher who showed improvement in 2009. However, the negative sentiment of the first half has proven to be grossly impulsive and reactionary. It seems likely that had the Rays not traded Jackson last off season, he would have been moved this year. Given one less year of cost control and a greater need to trade him, the Rays may have lost some leverage despite his statistical improvements. Matt Joyce still seems like reasonable compensation for Jackson.  He put up a slash line of .273/.373/.482 in Durham this season while playing above average outfield defense. The left-handed Joyce proved to be able to hit left-handed pitching putting up a slash line of .274/.345/.508 against south paws and will contend to play every day in 2010.

Next week we will take a look at the trade of the less-heralded Jason Hammel and draw comparisons to Jackson.  Given the difference in compensation (Matt Joyce vs. Aneury Rodriguez), the Hammel trade turned out to be the tough one to swallow.