Author Archive

Creating an App to Guide Pitch Design

Before we begin, here is the link to app being discussed:

Two months ago, I wrote a blog post arguing José Berrios should learn a cutter. My argument hinged on the striking similarities between Berrios and Corey Kluber and the fact that Kluber has a good cutter and Berrios does not. Since then, I’ve developed a more objective way to evaluate a pitcher’s current pitches and make recommendations to guide the pitch design process. Pitch design is the process of a pitcher making changes to existing pitches or adding new ones, often using high-speed video and devices such as Rapsodo or TrackMan to get the spin axis of the pitch just right to create desired movement. The app I’ve built creates targets for pitchers and details ideal pitch characteristics to give objective, quantitative direction to the pitch design process.

My plan is to turn the tool into a service for college teams to use for their pitchers in pitch design, but I’ve also created a version which uses Statcast data to create pitch design plans for big leaguers that I’ve released for free. I figured this would be a good place to share the Statcast data version and give a brief explanation of how it works (if you’re interested in a more detailed explanation of the tool, check out this post on my blog). Read the rest of this entry »

Wes Johnson Should Help Jose Berrios Develop a Cutter

This article was originally published on my blog,

Developing a new pitch can be a great way for a pitcher to have a breakout season. In 2018, we saw big improvements from Trevor Bauer adding a slider, Adam Ottavino adding a cutter, and Patrick Corbin adding a curveball. A new pitch can sometimes be the missing puzzle piece when trying to figure out why a player is good and not great. For Jose Berrios, a cutter might be that missing piece.

Examining Berrios’ arsenal

Jose Berrios has one of the nastiest curveballs in baseball. Instead of having the typical downward break associated with curveballs, Berrios’ curve averages 15.5 inches of glove-side break. This results from Berrios imparting gyro spin (think bullet spin) on his curveball rather than 12-6 top spin. Because of this, Berrios generates close to no vertical break caused by Magnus force, which is just a fancy way of saying the only drop we see on Berrios’ curve is due to gravity rather than top spin.

To pair with his curve, Berrios has a four-seam fastball which generates 9.5 inches of arm side run and 16.5 inches of upward vertical break due to Magnus force (causing the pitch to drop less), a two-seam fastball which generates 16.5 inches of arm-side run and 11.0 inches of upward vertical break, and a changeup with 14.5 inches of arm-side run and 5.5 inches of upward vertical break (the changeup will drop even more than the fastball since it is thrown slower and gravity will have more time to bring the pitch down). Read the rest of this entry »