All-Pro is tough. That's about it.
Rookie is like playing against toddlers, and Pro is relatively easy, but actually requires that you pay attention.
I couldn't consistently win All-Pro games until I was almost at 85 overall, and even then, I'm choosing not play any teams rated over about 82, because they will run all over you.
Stick to Rookie and Pro until you're closer to the high 70s, early 80s. And play poorly rated teams at first.
