Exit Velocity, Part I: On the Import of Exit Velocity for Hitters
The production of new data by means of new recording technology is exciting — and the more data we get, the better we can become at analyzing said data. We have come a long way since PITCHf/x was made available, but we still have much more to learn. We also now have Statcast data with defensive numbers and figures — as well as exit velocity for hitters and against pitchers — and right now that data is very interesting. But a lot of people are all working very hard to transform the data from merely interesting to actually useful. If it remains interesting without becoming useful, it is still fascinating information to have, but also trivial from an analytical perspective. Organizations want the information to be useful. Exit velocity, one of the streams of data rendered available by Statcast, appears to have the potential to be very useful. Right now, however, I am still unsure what we have, and I am not alone.
As Ben Badler of Baseball America recently noted on Twitter:
Common thing I’m hearing from execs: They have an enormous amount of new data, but they’re still learning to turn it into usable information. Even the more data-driven organizations are still just scratching the surface of separating signal from noise and understanding what has predictive value.
Back in September, I gathered a bunch of exit velocity data on major league pitchers, and attempted to make some sense of it. There seemed to be some evidence to suggest that if a low exit velocity was a repeatable skill, then it might be helpful in limiting home runs. Not exactly groundbreaking, but at least from my perspective, interesting. Others have studied the data and found that exit velocity was five parts the responsibility of the hitter and just one part the responsibility of the pitcher, so perhaps in retrospect, I should have focused on hitters. Below represents my current attempt.

