saw an article regarding distance
pw - rolls 2 feet for 1 foot hit
9i - 3 feet per 1 foot
8i - 4 per 1
sw - i get about 1:1

so if you have 15 feet to the flag and and your are 4 feet off the green, hit the ball 1 foot into the green with a 9i and should roll up to the pin.
1:3 = 5:15 mike.