Mike Pelfrey‘s home/road splits are almost astonishingly disparate. At home, Big Pelf is 3-0 with a 2.96 ERA and 1.089 WHIP. On the road, however, he is 1-7 with a 6.75 ERA and 1.654 WHIP. So the question becomes, why does Pelfey struggle so much on the road when he can succeed at home?
Some of Mike’s numbers at home and on the road are similar-namely, walks and strikeouts. At home, Pelfrey has struck out 27 and walked 13 in 48.2 innings. On the road, he’s fanned 29 and walked 17 in 52 innings. Pelfrey just isn’t a strikeout pitcher, owning a 5.1 K/9 during his career and a 5.0 K/9 this season, so he must rely on contact. The first question I asked myself, is could Mike’s troubles away from home be just bad luck? Maybe a little.
Since the walks and strikeout splits are similar, a major difference in Pelfrey’s home and away performances has to do with base hits. Opponents are batting just .220 against the right hander at home, but a whopping .318 on the road. However, the BABIP against Mike at home is a paltry .237, while the BABIP against him on the road is .326. In addition, Pelfrey’s FIP is 3.77 at home (higher than his ERA), and is 5.68 on the road (lower than his ERA). In other words, Pelfrey should be performing a little better on the road and a little worse at home than his initial statistics suggest. There is, however, one other important difference between Pelfrey’s home and road performance: home runs.
Last year, Pelfrey allowed only twelve long balls all season and pitched to a ground ball rate of 47.8% (his career mark is 48.6%). This season, Big Pelf has already served up fifteen big flies with only a 43.5% ground ball rate. Furthermore, his fly ball rate has jumped from 32.0% in 2010 to 41.2% in 2011. Given the spacious dimensions of Citi Field, it begins to make sense as to why Pelfrey might be struggling away from home this year.
What makes things interesting is that Pelfey has allowed more fly balls at home (47.7%) than on the road (36.0%). And yet, eleven of his fifteen home runs have come on the road. His high fly ball rate at home is certainly helped by Citi Field, the park which has the sixth lowest park factor in terms of home runs in the majors. Conversely, Pelfrey has been hurt by the cozier dimensions of some other ballparks. Out of the three long balls allowed at Coors Field in Colorado (which has a park factor of 1.093, where anything above 1.000 favors the hitter), two of them were classified as “just enough,” according to ESPN’s Home Run Tracker, basically meaning that the ball barely made it over the fence. Six of Pelfrey’s home runs allowed fall into this category. He’s also had the unfortunate task of pitching in some of the more homer-happy ballparks, including Coors Field, Citizens Bank Park (1.068), Miller Park (1.073), Yankee Stadium (1.164) and Rangers Ballpark in Arlington (1.671). Eight of his eleven road homers allowed have come in these parks. Pelfrey’s best road start came in Pittsburgh’s PNC Park, which has the second lowest home run factor (0.576, although he allowed a homer in this ballpark which fell into the just enough category).
So maybe there has been a little bit of bad luck involved regarding Pelfrey’s high home run totals. In some ways, though, Pelfrey has actually been lucky. Out of the fifteen home runs allowed, ten have been solo shots, with four having just one other runner on base (plus the Opening Day John Buck grand slam). During his next two road starts, Pelfrey will pitch at Dodger Stadium and AT&T Park, two locations that favor pitchers and have low home run park factors (0.811 and 0.512, respectively, with AT&T actually having the lowest home run factor in the Majors). Despite his struggles, it wouldn’t be surprising for Pelfrey to yield better than average road results in his next two outings.