I just re-cracked open my K&R Compendium (the latest one) and was reading about Perserverence. It seems obvious to me that there would be a relationship between number of shots and save percentage, and given the above post it seems that there is one.
What I'd like to know is why K&R came up with .6 ( I Think ) as the number to factor into #shots taken. It seems arbitrary to me. I'd like to see them use a number that comes out of research.