Jeff Zimmerman at Fangraphs today introduced the first glimpse of what I expect to be a fascinating line of collaboration work with Bill Petti. The concept is to divide all pitches into one of three groups based on their location: the "heart" of the strike zone, the "edges" of the strike zone, and outside the strike zone.
With these zones defined, each pitcher can be assessed to determine the percentage of pitches thrown in each of these zones. Intuitively, one would expect pitches on the edges of the strike zone to be more effective than those into the heart of the zone. The first application of this classification was in an analysis of Tim Lincecum's 2012 season compared to the average starting pitcher as well as his previous, highly successful seasons.
Lincecum’s Edge% was the lowest among all pitchers who threw over 1400 pitches last season. He was not able to pitch to the edges of the plate. Instead he was just trying to throw it across the plate and hope no one hit it. The problem is batters did hit it. The difference may not seem like much, but his Edge% is 5% points lower compared to Kuroda’s Edge%. If BABIP was a percentage (.309 BABIP = 30.9%), they would have an almost 4% point difference. A few less meat balls a game can lead to significant improvements over the course of a season.
Here Zimmerman alludes to the potential interplay between Edge% and BABIP, a thought echoed throughout the comments at the bottom of the article. It would appear that Bill Petti will be following up in the coming days with more details and findings on the subject. I am highly anticipating reading more about the topic, including any potential correlation between Edge% and BABIP.
Personally, one follow-up investigation that I would love to see performed is one that examines Edge% of pitchers broken down into bases empty situations versus those with runners on base (and perhaps with runners in scoring position). I would be curious if pitchers that record higher LOB% tend to alter their approach in a manner that increases Edge% (or at least decreases Heart%) with runners on base.
Given that the combination of BABIP and LOB% explains more than four fifths of the gap between a pitcher's FIP and ERA, any work that may offer insight into one or both of these two metrics is certainly worthwhile. We will have to stay tuned to upcoming articles that reveal what if any correlation exists between these three zones and the success of pitchers.
Questions for the community:
1) Do you expect Edge% to have any meaningful correlation with BABIP and/or LOB%?
2) What direction(s) would you like to see the researchers take in future work on this subject?
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