Same here. I usually have a team set up early season and leave it, bar a signing due to injuries or a non performer. Whenever my opps are starting to upgrade I start to slump. Doesn't even matter if I actually play them or another team. It almost makes you wonder if it calcualtes an entire season match after match.
Having said that, the beauty of randomness is that one can find evidence and arguments to support any theory you can think of...