I've never read anything that would confirm that suspicion, but average season length has definitely reduced over time, at least according to the data I crunched.
I've never read anything that would confirm that suspicion, but average season length has definitely reduced over time, at least according to the data I crunched.
Just looking back at some of the more popular series, it's obviously a recent trend:
Tenchi Universe - Ended September 1995 - 26 Episodes
Neon Genesis Evangelion - Ended March 1996 - 26 Episodes
Trigun - Ended September 1998 - 26 Episodes
Serial Experiments Lain - Ended September 1998 - 13 Episodes
Cowboy Bebop - Ended April 1999 - 26 Episodes
Love Hina - Ended Sept. 2000 - 25 Episodes
Blue Gender - Ended ??? 2000 - 26 Episodes
Last Exile - Ended September 2003 - 26 Episodes
Burst Angel - Ended September 2004 - 26 Episodes
Sunabozu (Desert Punk) - Ended March 2005 - 24 Episodes
Negima - Ended March 2005 - 26 Episodes
Lain was the only 13 episode series out of all of the ones I just listed. Now, occasionally you would get a series like Eureka 7 or Code Geass that go on for even longer, but 24-26 episodes was the standard.
Today, outside of the big serials like Bleach or Naruto, it's getting harder to find one that runs on longer than 13 episodes.