Introducing Heat+, a Brand New Fastball Quality Model
A few weeks ago, Camden Quick, who I will be interning with on the cape this summer, developed his own Stuff+ model to use in college ball. Taking after him, I’ve been working on my own pitch model. This is the first iteration of the model, and I plan on creating a better viewing application to go alongside with. With that being said, here is the preliminary version of Heat+. Heat+ is a pitch model designed only for fastballs at the moment. Heat+ was created in R, using XGBoost’s gradient boosting techniques to capture more. I took fastball data from 2023, 2024, and 2025, giving my model 3 different seasons to work with. The model is trained to predict the run value of a certain pitch. To define the run value, I used statcasts built in run value metric, “delta_run_exp”. This is the change in run expectancy from before the pitch to after the pitch. For a more detailed explanation on how pitch models such as this are made, read ...