Derek Holland pitched well in his first two starts, posting a 2.25 ERA. He showed better control than in his first two seasons, but more importantly kept the ball in the park, having yet to allow a home run. So far, the big change for Derek comes from working better on the edges of the plate. The following heat maps show his pitching against right-handed batters, which he sees much more often.
First, notice the location of Derek's fastball compared to his first two years in the majors (click all images for a larger version):
He still catches the plate with the change, but more toward the outside edge. Thrown correctly, this pitch should look like his outside fastball, but coming in slower and lower. The biggest change, however, probably comes from his slider:
In the past if the batter was caught by the slider, he could take the pitch and probably end up with a ball call. Now, with him hitting the corner, someone who lays off the slider finds himself down a strike. Since he tends to work this pitch inside, it serves as a nice contrast to his inside fastball.
Holland improved all three pitches by moving them all toward the edges of the plate. His challenge now is to keep this up for a full season.