On MLB Network recently, former Phillies closer Mitch Williams spoke briefly about Domonic Brown, who will take over in the outfield for Jayson Werth in the very near future. Brown struggled in limited playing time in 2010, but Williams said that those struggles would continue if Brown does not lower his hands.
As you can see in the animated .gif below, Brown starts with his hands high near his ears. By the time he makes contact with the ball, they are at belt-level. That is quite a bit of superfluous hand movement.
Resulting from that hand movement, pitchers were successful pitching Brown up-and-in according to Williams. To verify or falsify that claim, I went to the heat maps.
The heat maps indicate that, although he was swinging at up-and-in pitches frequently, he was not successful -- not only in terms of hitting for power, but simply making contact.
Brown finished 2010 with a .271 wOBA, which ranked all the way down in the eighth percentile of Major League hitters with at least 100 plate appearances. If Brown is to blossom into the offensively-potent player the Phillies organization has long thought he would be, he may need to take the advice of Mitch Williams and lower his hands.