Note: I found some errors in the data. Data below has been corrected, as well as some conclusions — BP
Yesterday, Jeff Zimmerman examined how Tim Lincecum‘s performance has depended to some extent on his ability to pitch to the edges of the plate. Last year, Lincecum was one of the worst starters in the game in terms of the percentage of his pitches thrown to the black. Coincidently (or not so coincidently), Lincecum suffered through his worst season as a professional.
As with many things, Jeff and I happened to be investigating this issue of the edge simultaneously. Of course, we were not the first to dabble in this area. Back in 2009, Dave Allen noted that differences in pitch location–specifically horizontal location–led to differences in BABIP.
Like Dave, I was curious about the overall impact that throwing to the edges–or the black–has on overall performance. My thinking about pitchers throwing to the edges naturally led to some hypotheses:
- Throwing a higher percentage of pitches on the edges leads to lower FIP.
- Throwing a higher percentage of pitches on the edges leads to lower ERA.
- Throwing a higher percentage of pitches on the edges leads to lower BABIP.
- Throwing a higher percentage of pitches on the edges is associated with lower four-seam fastball velocity.
I think the first three hypotheses are intuitive, but the last one stems from the idea that as a pitcher ages and loses zip on their fastball they cannot remain successful unless they increase their avoidance of the heart of the strike zone.