A New BABIP for a Statcast Era
Last week I wrote about my efforts to build batted ball stats exclusively using data from Statcast. I described my method for classifying launch angles into larger launch windows, and then separating these windows into a series of buckets based upon their launch velocity. Whereas others have used combinations of line drive, opposite field and hard hit rates to construct approximations for launch angles, I am, for better or worse, exclusively using the launch angles and speed, discarding every other facet of the game in the process.
Many have worked towards teasing apart the luck and skill aspects for balls in play. Up until the last calendar year, perhaps the best methods available involved incorporating line drive and opposite field hit rates. Line drives due to their significantly higher likelihood of being a base hit, and the opposite field hits because they are more likely to be line drives. However, there is a lot of information lost to this sort of categorization. For instance, where was the ball hit, how hard? Using Statcast data, we can build a more granular view of batted balls, and define new types of batted balls, along with their observed characteristics. Now that we are in the Statcast era, the line drive, fly ball, ground ball, and pop up categorical system may become obsolete.
