Wills: Uncovering the secrets of the 2019 postseason baseball

From SABR member Meredith J. Wills at The Athletic on April 6, 2020:

There are some undeniable facts about the baseballs used during the 2019 regular season. Compared to previous years, the balls were rounder, the seams were lower, and the leather was smoother. The first two characteristics were ultimately connected to the lower drag that produced the 2019 home run surge. The second two characteristics led to the grip issues reported by some pitchers.

Identifying truths about the 2019 postseason baseball has proven to be more difficult. On Oct. 1, the ball seemed to suddenly deaden, and data showed the higher drag wasn’t consistent, but varied game-to-game. When questions were raised about this, MLB stated that all balls used during the postseason were pulled from regular season batches, something I attempted to verify by looking at postseason balls purchased directly from Rawlings. My results found those baseballs were a mix from both the 2018 and 2019 regular seasons. However, when asked about the findings, MLB and Rawlings insisted that, despite their apparent marketing as game balls, the baseballs used for that study were intended strictly as “commercial” or “memorabilia,” and therefore were not representative of anything used in actual games.

Read the full article here (subscription required): https://theathletic.com/1723029/2020/04/06/uncovering-the-secrets-of-the-2019-postseason-baseball/

Originally published: April 7, 2020. Last Updated: April 7, 2020.