I noticed that fangraphs had an article about Hunter Pence called "Hunter Pence's sliding production." I can't say that I see anything I didn't know in this article. As the title suggests, the article is not exactly a glowing report on Pence. But I think most of us who have watched Pence realize that plate discipline has been a major issue for him. I overstated things when I said the article didn't say anything I didn't know. The author dug out a few useful tidbits of data. For instance, Pence saw more sliders than any hitter last year, and he saw a lower proportion of fastballs than any hitter. (Dan Uggla is the hitter who came the closest to Pence in terms of slider attacks.) That demostrates what we all knew: pitchers had detected a definite weakness and attacked it ferociously. The article also points out Pence's proclivity for swinging at balls outside the strike zone and taking pitches in the strike zone. That is one of the reasons that plate discipline is so important to hitting with power. Plate discipline isn't just about walks, but rather allows the batter to put himself in a position to hit HIS pitches.
The comments section of the article has some dialogue between supporters of Pence and the author. You might find this interesting, because it discusses Pence's improved performance at the very end of the year. Pence supporters see it as a sign of a real change in Pence's approach, while the author is skeptical. If you go back to some of the September game threads, you will see that I commented a few times that Pence's plate discipline seemed to be much better, and it appeared to lead to greater power production. Pence had a .581 SLG and a .969 OPS in September. The author makes a fair point that this easily could be the normal fluctuations between good and bad months over the course of a season. However, the better plate discipline did seem apparent in watching him. We certainly can hope it carries over. But at this point it is just that, hope, rather than concrete evidence of a change.