I play with fictional players and play as the in game manager, letting the AI be the GM and handle everything else. I play out all of my games - it's a challenge because the computer GM makes curious decisions now and then.
I've always played this way and have made the playoffs a few times but I have never won it all, yet.
I just started a new league and I am 11-4 in my first 15 games, so maybe this will be the season