One interesting match-up in the upcoming World Series is all of the great left handed Phillies hitters against a Yankees’ rotation that features two solid left handed pitchers, CC Sabathia and Andy Pettitte. The Phillies will face a lefty starter in at least half of the World Series games no matter if the Yankees go with a three or four man rotation or how many games the series goes.
The biggest issue for the Phillies is Ryan Howard, who is a very bad hitter against LHPs.
On the splits page, you can see that the biggest difference is in his ISO and K rate. On the other hand, in recent years, the difference in his walk rate against LHP and RHP has decreased. Looking at a pitch-by-pitch basis he takes more called strikes against LHPs than RHPs (13% of pitches versus 11% of pitches). His whiff rate increases from 28% against RHPs to 38% (Mark Reynolds territory) against LHPs. Here is how his whiff rate varies by horizontal pitch location:
Interestingly, he whiffs less on inside pitches from LHPs than RHPs. Next, let’s check out his slugging on balls in play:
Here you see a big difference. Against RHPs he maintains high power across most of the plate (it peaks in the middle of the plate, not surprisingly). But against LHPs his power is relegated to the middle-away, and it falls off sharply inside.
Putting the graphs together explains his overall weakness against LHPs. On inside pitches, he doesn’t whiff that often, but has little power. On the outer portion of the plate, he can hit for some power, but he whiffs at a huge rate.
If you project Howard as roughly a .450 wOBA hitter versus RHBs and roughly a .300 wOBA hitter against LHPs that works out to a 0.13 run difference per at-bat. That is over half a run every four at-bats, an enormous difference and significant cause for concern for the Phillies in the games they face Sabathia and Pettitte.