I made a league using
Tiger Fan's Fictional 30's League Template and am noticing an obsurd amount of middle relievers being released by every team in the league on the 1st of each month.
The league setup looks like this (if it helps):
Use of relievers: rarely
Use of closers: rarely
Pitcher endurance: normal
Typical rotation size: 4 man
Also, there are 3 levels of minors and I've noticed that there are roughly 3x as many middle relievers in the league than starters. Here are some sample transaction pages for one team.
http://suicane.com/jeffsdirlol/team_...ns_5_1943.html
http://suicane.com/jeffsdirlol/team_...ns_6_1943.html
http://suicane.com/jeffsdirlol/team_...ns_7_1943.html
http://suicane.com/jeffsdirlol/team_...ns_8_1943.html