Some bow manufacturers recommend that you have the arrow set at a particular height for the optimum tune with their bows. For instance, Ross recommends that the bottom of the arrow be even with the middle of the Berger hole. Some want the middle of the arrow through the middle of the hole and so on.

My question to the manufacturers is, are the recommendations to get optimum efficiency or straightest nock travel? I'm suspect and am hoping it's the latter.