The more consistent your efforts are towards successful results, then I would say the more scientific you are.
Based on my study the closer you reach your potential, the less range your sales would have over a group of contacts. So if you're a weak seller, then your results may range from 0% to 6% from one day to the next (the difference between high and low is 6%). If you're a strong seller, then it may range from 7% to 9% (the range here is 2%). I realize that the numbers may vary depending on your job and business, but overall I have found the range to narrow as you get better at selling, all else equal (e.g. the offer).
I may go out on a limb, but I believe that when you hit your full potential in selling, your range may be 0% beyond which you can't improve. (scientific perfection?)
Anyone want to comment?