Knowledge of the rules is definitely my Achilles heel when it comes to competitive play. I have pretty good flipper skills and ball control, but if it isn't a game I've owned, I generally don't know the rules that well. I rarely play in tournaments, but I know I'd do much better in league if I took the time to really study the rules to all the games. That being said, I simply don't care enough to do it. I guess that makes me more of a casual player, and I'm fine with that.