Arthur: MLB admits lower seam height caused the home run surge

From SABR member Rob Arthur at Baseball Prospectus on December 12, 2019:

After four years of home run fluctuations dominating MLB’s offensive production and headlines, the league is finally ready to tell us how. In a new report issued Wednesday, the commission of scientists and statisticians tasked with studying the baseball revealed that seam height is the primary factor altering home run rates in the regular season. They also admitted that drag spiked in the 2019 postseason, confirming my reporting at the time.

The impact of the commission’s findings is massive, with implications for understanding hitting styles, pitching, and playoff baseball, among other topics. MLB has yet to publish the full report, but I obtained a copy. There are many different threads in the report, some of which can be addressed with careful data analysis in the future. For now, I’ll go through the principal findings and the major implications of each in the following sections.

Read the full article here:

Originally published: December 12, 2019. Last Updated: December 12, 2019.