Everything default. I've had Beanie Wells break the record for most yards in a game. Albiet my front 7 sucked but he broke off huge yardage.
There are a few games that I can shut down the run but I've had a bunch of games where they just abuse me in the run.
I'm telling you unless you are somehow god at this game or just find a way to cheat the ai (which then just really amounts to you cheating yourself out of some fun games) Complete default All-Madden (yes default sliders, default penalties, default speed threshold, etc. Especially if started fresh in a CFM without messing with any settings as adjusting them at all can make the game easier) should make the game fairly competitive.
Disclaimer: Beanie Wells was the only one who ran for THAT many yards on me. Generally it was about 150 yards per a game against me. Also in skill level I'm about a 3.5 out of 5 so I'm good but not the greatest so your results may vary a bit but most people I've talked to who play default all-Madden have preferred that over anything else this year.