Is there a limit to total improvement in a season?
It seems its 100 though I would welcome any evidence to refute that assertion.

There's no limit, though unlike when potential first came out, it's VERY unlikely that you'll see any improvements above 100.  Though when potential was still going haywire some players increased as much as over 150 points in one season. 

Typical (overall) improvement for a solid, high potential player is probably in the 50-70 point range, though it is possible to see improvements around and potentially even above 100. 

I just had a DII sophomore finish the season with 99 points of improvement.  Most I've seen since they adjusted potential.

http://www.whatifsports.com/hd/PlayerProfile/Ratings.aspx?tid=0&pid=1698382

http://whatifsports.com/hd/PlayerProfile/Ratings.aspx?tid=0&pid=1750396

This guy went up 116 in Tark. So no 100 is not the limit, and overall there is no limit. I had a guy go up 100 and he only started 12 games including exhibition, had he started every game I'm sure he would've gone up around 110.

I just had a guy go up I think 102 points. He started every game(and is a freshman) and had a very good starting WE

I had a guy go up 112 points last season.  He was an international guy with a bunch of high potentials and 80ish WE.  With a lot of high + lots of minutes + WE>70 you should see at least 80+ point improvement.  As evidence by a couple guys in this thread, triple digits is very possible.

Posted by kmasonbx on 1/26/2011 4:52:00 PM (view original):
http://whatifsports.com/hd/PlayerProfile/Ratings.aspx?tid=0&pid=1750396

This guy went up 116 in Tark. So no 100 is not the limit, and overall there is no limit. I had a guy go up 100 and he only started 12 games including exhibition, had he started every game I'm sure he would've gone up around 110.

hey i know that guy

I had a dII player at St. Josephs (IN) from FR-SO improve around 110.