Using Zone% to Find Breakout Minor Leaguers
Last May, Rob Arthur of Baseball of Prospectus unveiled new research implying that PITCHf/x data can be used to forecast hitter performance. Essentially, he found that hitters who saw fewer pitches down the heart of the plate late in the year often outperformed their projections the following season. The theory behind this phenomenon is pretty straightforward. A pitcher knows a good hitter when he sees one, and chooses to approach him with caution. So when pitcher’s change their approach, it’s often an early indicator of improved talent from a hitter.
This finding gives us yet another tool to use in forecasting hitter performance. As great as statistical projections are, they can sometimes be a bit slow to recognize a breakout when it happens. Simply put, it’s not easy to identify the one breakout from the sea of small sample size flukes. However, Arthur’s research hints that incorporating pitch locations can help us get ahead of the curve.
This past January, Eno Sarris wrote a piece for JABO where he applied Arthur’s findings to 2014 data in an attempt to identify breakout candidates for 2015. Eno noted that this type of analysis is most useful for players who are relatively new to the league. For this reason, he limited his analysis to hitters with fewer than 800 big plate appearances.
I decided to dig a little deeper. To my knowledge, all applications of Arthur’s research have looked exclusively at big league hitters. However, in what follows, I make my best attempt at expanding this practice to hitters in the minor leagues. Read the rest of this entry »