2009 White Sox Player Review: Bobby Jenks

While it's no guarantee that Bobby Jenks pitched his last game with the Sox Sept. 17, if the Sox are looking to shed salary in the offseason Jenks likely will be first on the chopping block. He'll probably be due about $7 million after arbitration, and with Matt Thornton waiting in the wings, the Sox wouldn't be completely out of line to deal away Jenks.

He's been their full-time closer for the last four seasons, and he's been pretty successful over that time. But a closer is the easiest player to replace on a roster—and Jenks is no exception. We don't know if Thornton would do worse than Jenks' 29 saves to six blown saves, but there's a good chance he wouldn't be worse than that given the track record of former setup men taking over a closer role.

I'm not sold on trading Jenks, but I'm also not sold on keeping him. He could end up costing more than he's worth in 2010, yes, but trading him would deplete the team's bullpen depth if Thornton does move into that closer role.

Key stats
G: 52
IP: 53.1
W: 3
L: 4
ERA: 3.71
FIP: 4.47
BB: 16
BB/9: 2.70
SO: 49
K/9: 8.27
K/BB: 3.06
S/BS 29/6
HR/9: 1.52
WHIP: 1.28
OPS: .725
GB/FB: 1.47
BABIP: .298
WAR: 0.4 

Coming into 2009, Jenks had allowed 12 home runs in 235.2 career innings. He allowed 12 in 53.1 innings in 2009. That's an incredibly significant jump, and if the White Sox do choose to keep Jenks heading into 2010 they'll have to hope that '09 home run total was an outlier and not a trend.

You have to wonder if those home run issues were caused by Jenks overusing his fastball. While Jenks threw that pitch harder than he did in 2007 and 2008 (94.8 mph in '09, 93.8 and 93.9 mph in '08 and '07), he threw it with the highest frequency of his career. Prior to 2009, the most Jenks had ever thrown his fastball was 72.4 percent of the time—in his rookie year of 2005. In 2009, Jenks threw it 76.4 percent of the time.

On top of that, FanGraphs rated the pitch as below average . So those numbers say Jenks threw what was a somewhat ineffective pitch too much.

Maybe Jenks lost confidence in his curveball, which he threw just 8.5 percent of the time—the lowest percentage of his career. However, FanGraphs rated his curveball as his best out-pitch, so maybe it wasn't a confidence thing. It could have been that Jenks and the Sox were being too selective with that pitch.

Given Jenks' career history, that's not a good thing. Over the course of Jenks' career, the more he throws the curveball, the more swings and misses he gets on pitches out of the strike zone.

That's not exactly groundbreaking—especially because Jenks isn't consistently throwing his fastball in the upper 90's like he did when he first came up—but what is telling is Jenks' BABIP over the last three years.

Jenks was able to get away with throwing a fewer percentage of curveballs in 2007 and 2008 because his BABIP in those two years was low (.252 and .261, respectively). The jump in contact—both out of the strike zone and overall—didn't lead to decreased success because a low percentage of batted balls were falling for hits.

However, Jenks' BABIP rose to a more sustainable .298 in 2009, meaning that more of those pitches hitters made contact with out of the zone fell for hits. That's a good way to explain at least some of Jenks' jump in FIP to a career high 4.47 (1.20 higher than his career average).

The reasonable thing to do to combat that BABIP would be to throw more curveballs then. That'll hold especially true if Jenks doesn't have good command of his fastball—which was behind many of the home runs and hits Jenks gave up in 2009. And given that he threw more fastballs in 2009, it's not surprising that '09 was the worst year of Jenks' career.

But you know what? If in the worst year of Jenks' career he still saved 29 of 35 games, that's really not awful. I'd have to hope that he'll make some adjustments heading into next year, and I'd have to think that those adjustments would lead to more success.

I'm not guaranteeing that Jenks will have success, but if he throws fewer fastballs with better command and throws more curveballs, I think he'll do just fine. Will it be good enough to justify his impending pay raise? Maybe, maybe not.

But if Jenks makes those adjustments, he'll be worth keeping around. The last thing the 2010 Sox need will be to have a bullpen that's not as deep as it could be, and keeping Jenks will keep the depth of the bullpen at a good level.

So unless the Sox find a way to get a good setup man in return for Jenks in a trade, they probably should keep him around and see if he can rebound.

This article was originally written for Examiner.com .

Check out my previous player reviews at my Examiner page :

• Mark Buehrle
• John Danks
• Gavin Floyd
• Jake Peavy
• Freddy Garcia
• Randy Williams
• D.J. Carrasco
• Tony Pena
• Scott Linebrink
• Octavio Dotel
• Matt Thornton

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