I hate this system with a fiery passion. On the low end it turns a doable-but-not-great chance of hitting, say 30%, into a you-might-as-well-not-try 9%. I wanted to punch someone when I read about the fake percentages on a forum and suddenly understood why I never seemed to hit anything below 50%.
edit: My example's not averaging, forget which game I was using where they multiplied them together somehow.