Introduction This is the final update that I'll be making to my pitch quality model. The main update is the inclusion of spin/movement axis differences which was a clear weakness of my previous work. In addition, I've reworked the format of the underlying models. These approach changes have limited me to data from 2020 onwards, but greater accuracy has been achieved in almost every model prediction. This model update will only be used on my main website , other apps will continue to use the old version. Pitching grades from before 2020 will be grandfathered in using the old model. For more information on older versions of the model, see these blog posts: [1] , [2] Spin Axis and Efficiency On a pitch-by-pitch basis, the observed spin and movement axis from Statcast data can be compared to produce the axis difference metric, commonly attributed to Seam-Shifted Wake (SSW). Increased SSW is generally correlated with improved performance as seen in the graph below, which used the o
Sabermetrics and more