Wii challenges

For those of you keeping track, I have fallen behind in the bowling challenges; however, I am now in 2nd for the Big Brain challenge. The furrent standings are listed on the right side. Yes the are scores such as B minus minus. I guess that means .... better than C++ ... but not as good as B -. I don't know... seems kinda odd but I will won't strain too much trying to understand since I am ahead of that.