Thats WHY it is important in my opinion to get a dog from dogs that work so you have some basis for knowing your dogs potential VS. picking up dogs at the pound, off the side of the road, or any scatterbred dog a friend might offer you for free.
Which is my arguement as to why I only get papered dogs. It shows the consistency in the line, or inconsistency, but either way it lets you know what you get out of your dogs.