Players Required over the Years

Just was thinking about the pen and how many were used there this year and the injuries so I thought 'how has this changed over the years'?

All data via the Lahman database (http://www.seanlahman.com/)

Some basics to start...

In 1871 MLB had only 115 hitters used, 19 pitchers (14 starters, 7 relievers)

The lowest number of hitters used was in 1878 with just 77 hitters in the majors, and 1877 had just 92.

The lowest number of pitchers used was in 1974 - only 17 total (14 started, 10 relieved)

14 starters is the lowest total (1871/74), 7 relievers the lowest (1871). Huh, 7 relievers is a normal game now isn't it?

The lowest after 1900 (once the AL was formed) was 1904 with 364.1904 also was the…