I quote it because if you're way above average in some areas, average is acceptable. You want to avoid being grossly below average in any area, like giving Corey Patterson, Neifi Perez, and Jose Macias 676 plate appearances in the 1-2 spots of your batting order. If the Cubs had had some guys that, oh, I don't know - got on base? - in those spots, the LF situation wouldn't have been nearly as big a problem as it was.