Andrew Grant interviewed Dr. Lloyd Smith in this July 2021 article published in Physics Today.
From a physics perspective, the relationship between a baseball’s spin and its trajectory has been tested extensively over the past few decades, and it’s clear that even a small change in spin rate can affect hitters’ chances of success. However, quantifying the advantage of grip-enhancing substances is a stickier proposition. “There are lots of opportunities to give opinions,” says Washington State University sports scientist Lloyd Smith, “but no one knows the real impact of these substances.”
Andrew Grant, “The physics of baseball’s sticky situation”, July 8, 2021, Physics Today