It should be hit as a 20-22 footer roughly and it will roll roughly 30. Who'd want a 30 foot putt to roll 42?
What I meant by clear was the method for remembering such as a 1/2 or 50% more power, a 1/3 or 33% less etc, just like the examples below, This link also from Druss to a spreadsheet: https://docs.google.com/spreadsheet/ccc?key=0Apk9DKK3f4CHdHVzVWNubEJZZkZSSkFvWEJtVk9YNlE&usp=sharing
DrussTheLegend has been very helpful, I hope these help you improve your putting.
I will keep updating this post as I get the info/tips.
Black grid = Flat ~ Blue = Uphill ~ Red = Downhill
Yellow or brighter = PRAY! :-)
Below is for a 30 foot putt on black ie: flat greens.
Champ Speed (13 stimp) = 72% or 30% less power.
Tournament (12 stimp) = 74% or 25% less power
Fast (9 stimp) = 97% or 3% less power
Slow (7.4 stimp) = 113% or extra 15% power.