I think I remember there was a guy who used to post here that just might be able to answer that question.

I asked AEC4 for the answer and here is the way it works
The original ESC procedure called for you to be allowed to take a double bogey for each stroke of your course handicap. In other words, if you were a 6, you could take at most 6 doubles. That was way too confusing for people, so then they changed it to 6s for 0-9, 7s 10-19, 8s for 20-29, 9s for 30-39 and 10s otherwise. Well, they found that was too skewed for 0-9s, so they changed it to double.
Basically, the formula is not perfect, but the other was too difficult for golfers to use, so people were ignoring ESC. this one is simpler.