Expansion Era
This period of the league's history is named for two separate expansion periods.
Following the 2016 season, six managers left the league, reducing the total number of remaining active managers to ten. Four new managers were added for 2017: Logan Camillo, Ryan Cutino, Matt Hogan, and Mike James. Matt and Mike would leave the league after one year, while Ryan left after two. Cody Marshall, Trent Pickett, and Ders Velischek joined to replace them respectively.
Due to the Major League Baseball season being shortened by the COVID-19 pandemic, the PLFB would operate a six-week regular season in 2020. In an effort to maximize competition in such a short season, it was decided to have four divisions of four managers, with each manager playing each other member of his division twice in the regular season. To do this, two new managers were needed to bring the total to sixteen, thus Dylan Davies and Eric Miele were added. As the league returned to a normal schedule in 2021, both Dylan and Eric would remain in the league.