Like everyone said - judging a buck's rack while it's still on his head and he's walking around can be a tough thing. Sometimes a big-bodied deer's rack will appear smaller than it is, and a small deer's rack will appear bigger than it is. A small rule of thumb I was taught a long time ago that usually holds fairly true is that if a buck's inside spread is out to the tips of his ears you're looking at about 18". Most bucks with an 18" spread, at least 8 points, and somewhat decent mass will score every bit of 110". So I guess unless you have a buck coming in with a tight, massive rack with points sticking out all over the place - try to hold out for one that's about out to his ears. That's pretty much the standard I've always gone by anyways.