[outfinofulpv]

I measure greens off of satellite photos and know exactly the width and depth before I play any golf course and it is rare, extremely rare, for any green to be smaller than 15 yards in any one dimension and then only on a very short par 3.

You said the average was 20 yards in the last post. Check out through the satellite images the 1st 3 holes at my course.

Par 4 - Tiny green that is less than 10 yards wide
Par 5 - Less than 12 yards wide
Par 3 - Less than 10 yards wide.

Just some examples from my course and basically all the courses around me are no where near your average of 20 x 20 yards. That is not to say that they are not 20x20 where you live, but just that they are not around here. Private clubs around here all have tiny postage stamp greens. Resort courses around here have huge greens.