For what it is worth, I believe Peter Dobereiner once wrote a column on that subject. If memory serve his "yard like" definition:
1) On the tee extend your arm and cover with your hand the area you should land into
2) If on the majority of holes, 2 fingers are enough to cover the area, this is a championship course
3) I forgot the name given for the palmed, 4 fingered, and three fingered course, I may have an idea
for the one finger case which was not covered in the column
I assume that split fairways go to the highest finger tally, i.e. 2 and 2 is championship and 2 and 3 would end up in the three fingered basket.
Olivier