One of the biggest disappointments offensively this season has been Conor Jackson. He had a very poor start to 2009, hitting just .149 over his last 21 games before the cause we finally found. Jackson had contracted Valley Fever, a an illness which truly does not put the "fun" in "fungal". This debilitating lung diseases developed into pneumonia, and sapped Jackson's energy completely - the rest of his season was wiped out, with an abortive attempt to return ended almost before it started.
However, he had a great winter, and solid spring, pronouncing himself fully fit for Opening Day - great things were expected of Jackson in left-field and at first-base. But his OPS+ so far in 2010 is only 74: that's dead-last among the regular D-backs, and ranks #180 among the 214 major-leaguers with 150+ plate-appearances. So, it's time to look into the troubling conundrum: what's up with Conor Jackson?
And in case you're thinking the latter numbers are affected by Valley Fever, Jackson line for this season is .242/.336/.333, hardly distinguishable from the overall stats in the past two years. The drop off in home-run production is starting: from one long-ball every thirty at-bats or so, to one every 215 at-bats. This would probably be more acceptable if they were simply turning into doubles, but they seem to be turning into outs more than anything else. About the only aspect of his offensive game which has been retained is his plate discipline, with Jackson walking not far short of the number of times he strikes out.
However, it's not first time Jackson's power numbers have shown a significant dip. Take a look at this article, which dates all the way back from April 2003, when CoJack was a theater major at the University of California. It would take very little in the way of editing for much of what the article contains to be relevant to Jackson's current situation:
Since returning, Jackson has seen his home run total drop from 16 in 2002 to just six this year... The drop in home runs has concerned some major league teams, but Jackson's overall game will make him an early first-day selection in the amateur draft on June 6... In fact, Jackson's most developed skill set may seem to border on the mundane in this day and age of tape-measure home runs. He is quite simply one of the best players in the country at getting from the batter's box to first base without making an out. "Ever since I was little, my dad would throw to me, and he threw a lot more balls than strikes." Conor said. "That way, I learned not to swing at bad pitches."
Still, things got so bad recently, that Jackson was benched in favor of Gerardo Parra, AJ Hinch saying, "I've given Conor a couple of days off on purpose to clear everything away from the last series... When a hitter is going well, you want to leave him in the lineup. Sometimes when a hitter is going not as well, getting him away from at-bats can kind of restart a guy." It does seem to have helped a little: since returning on June 1st, Jackson has had seven hits in 19 at-bats (a .368 clip), including his first home-run since April 14th, 2009 - and that came off Ubaldo Jimenez, who had only allowed one other shot this season.
There are some metrics which tend to suggest this improvement should continue. Jackson's BA on balls in play is below average at .270, twenty-five points below his normal number. And that's despite a startling jump in his line-drive percentage, which is up at a career-high level of 26% - that's the sixth-highest in the league for anyone with Conor's number of plate-appearances. Conversely, his infield-fly rate, an elevated rate of which can cause BABIP to drop (because infield-flies almost always become outs - see Chris Young last year), is below MLB average, at 11.%.
These numbers would generally suggest a better BABIP than average, not a worse one. But you break Jackson's BABIP down further, into line-drives, fly-balls and ground-balls, and compare the numbers for each to league average, hings get even more interesting.
Ground-balls: Jackson BABIP: .163; 2010 NL Average BABIP: .234
Fly-balls: Jackson BABIP: .119; 2010 NL Average BABIP: .139
Line-drives: Jackson BABIP .633; 2010 NL Average BABIP:.716
So its not just, say, that CoJack's ground balls that are finding fielders: his fly-balls and even his line-drives are all turning into outs at a greater than expected rate. The fly-ball number is in line with Jackson's career number (.118), but the ground-ball and line-drive BABIPs are well short (.241 + .713 respectively).
Fangraphs.com recently suggested this was because "Jackson's line drives have been more of the Juan Pierre variety than that of Albert Pujols." But I'm not sure on what they are basing that assessment, since Pierre's career BABIP on line-drives is .707, hardly any different from league-average, and still 74 points better than CoJack has managed this year. I tend to think that we may simply be seeing true bad luck in operation, and that the recent burst of output from Jackson is things regressing - in a positive manner - towards the true mean. Of course, I am certain there are those who will think otherwise, so I guess we'll see what happens going forward.
[All stats through June 8th]