Firstman: Are expanded rosters leading to longer games?

From SABR member Diane Firstman at Value Over Replacement Grit on September 13, 2016:

Much has been written about the ever-increasing length of ballgames.  Attention has recently turned to the impact of expanded September rosters on game length and “level playing fields for both teams”. Here I’m only focusing on the game length issue vis-a-vis September callups.

Using game length data culled from the Retrosheet game logs for 1920 through 2015, here are the month-by-month average game lengths in minutes, by decade (March and October games excluded due to their relative small number of data points). The final column here, “APR-AUG vs. SEP” takes the average game lengths for the first five months and compares it to the average for September. Negative numbers mean that September games were shorter on average.

Read the full article here:

Originally published: September 13, 2016. Last Updated: September 13, 2016.