Fastball Adverse

Marginal Revolution posts a snippet of a yet-to-be published paper on pitch selection.

Abstract: Using Pitch F/X data covering over 6 million pitches, we document that pitchers are averse to throwing fastballs. Controlling for the state space of a baseball game, including balls, strikes, outs, inning, run differential, and pitcher/batter fixed effects, we find the pitching team is more likely to win the game when throwing a fastball. This is inconsistent with a mixed-strategy equilibrium where the pitcher’s utility is winning the game. We document that fastballs are riskier, leading to more outs, but also to more extra-base hits. We outline a possible incentive problem between the team and the pitcher, who has preferences over remaining in the game, similar to career concerns (Holmstrom 1998), leading the pitcher to be risk-averse. As suggestive evidence, we show that these effects are more prevalent later in the game, and that rookie pitchers, who have less leverage over pitch choice, do not exhibit this tendency.

If I am interrupting this correctly, a fast ball is a high-risk, high reward pitch, and the trade off is between OBP and slugging percentage.

The conventional wisdom is that pitchers start hitters with fastballs, then get them out with some kind of change of speed or breaking ball. There are some pitchers who reverse this, starting the batters with slow or breaking pitches, then finish with the fastball. Maybe this abstract suggests that’s a better way of approaching hitters.

As to the rookie observation, younger pitchers may not have developed other pitches, so until they do, their best choice may be the fastball. Since they are younger, they might also throw faster, and the fastball is more effective at high speeds. I hope the paper is available online at some point.

from baseballmusings.com http://ift.tt/2foZNDZ