You're not reading what I'm saying correctly.
A small change in scoring can cause a huge change in traffic.
But a huge change in traffic does not mean you need to make a huge change on your site to get the traffic back.
If you drop from position 1 to position 3 on average the average score awarded to your pages changed 0.03% relative to the other pages you're competing with. (Yes, the traffic will change more than that % in almost every case, but that doesn't mean you need to make huge changes to your site to get the traffic back.)
Increasing your average score by 0.03% relative to other pages you're competing with does not usually require a huge change on your site.
Changing your average score by say 3% or 10% (going from 1 to 30 or 1 to 100) usually requires a larger change.
In one case (0.03% difference) you're really close to ranking #1 and the traffic that comes along with it. In the others (3%, 10%, some other larger % difference relative to the whole of the pages in the index) you're "out of the top spot" (and the traffic that comes with it) by more than "just a little adjustment" in most cases.
[edited by: TheOptimizationIdiot at 8:08 pm (utc) on Mar 9, 2013]