The inspiration for this study came from this blurb in a recent Mining the News.
In the past, the general rule is that a higher fastball velocity leads to more strikeouts. Once spin data became available, the link between more spin and strikeouts was quickly found.
And they can go in separate directions. After going way too deep down this rabbit hole, I came out with a simple formula.
Before diving in, a few items need to be cleared up. First, other factors besides velocity and spin can affect a fastball’s effectiveness such as pitch location, deceptiveness out of the hand, and how often the batter has seen the pitch. The key with this study is to have a simple formula to start evaluating fastball changes for the accessible stats.