Clack, posted a link to an excellent, per usual, bit of analysis from Fangraphs. The article dealt with Hunter Pence's plate discipline utilizing Fangraphs new plate appearance statistics. Like clack's reaction to the article stated: there wasn't a lot we already didn't know, but it certainly made some things concrete. These stats are relatively new, but their pretty much intuitive. The article points out that Hunter Pence saw more sliders and few fastballs than anyone in the league, and as a result, he was swinging at more pitches outside the zone.
The article, seemed to me at least, to imply an inherent weakness of Pence's to the slider. While I completely agree that Pence needs to work on his plate discipline like I need to go for a 10 mile run to burn off yesterday's gluttony, I don't believe that Pence is some kind of lost cause because he can't lay off the slider. My view on Pence was that he's young and still feeling out big league pitching; that he has no real weakness other than nerves and still being green behind the years.
According to Fangraphs' new stats, Hunter Pence saw 668.45 sliders in 642 PA, at a rate of 28.3% of all the pitches he saw. In 2007, Pence saw 357.2 sliders in 484 PA, at a rate of 20.4% of all the pitches he saw. Pence swung at 734.58 pitches outside the zone in 2008 and 521.8 in 2007. That's 31.1% and 29.8% respectively. While percentages are good, and they drive home the point, I wanted something more concrete to look at, for myself. Pence saw .74 sliders/PA in 2007 and 1.04 sliders/PA in 2008. That's a huge increase. Pence swung at 1.08 pitches outside of the zone/PA in 2007 and 1.14 pitches outside of the zone in 2008. That's not a huge change. The change in sliders seen in now way can be accounted for in his outside of the zone swinging percentage.
Looking at the percentage of pitches he takes for strikes, it increased by 3.9%. I don't know how significant of an increase any of the percentages are because there hasn't been a lot of with them, but that seems like a pretty large increase. What that increase tells me, along with the fairly consistent outside of the zone swinging percentage, is that Pence is up there guessing. It's not that Pence has a weakness, its that he needs to develop an eye for the strike zone, something that he apparently had in the minors. I don't think him reestablishing his strike zone is out of the question because I think its just a matter of confidence and comfort -- not of inherent weakness.
Like I said, I'm not an authority on these numbers, but thats what I got from playing around with them.