Fatherbrown:
I'd like to learn that-that she did.
they are dividing up the power scale. so here, for woods and irons, the scale is 77mm long, each 7.7mm is 10% of the scale (use a scale of your choice)
.......though of course, 50% power doesn't = 50% distance
i don't use this myself, but it could be useful for pitch, chip, flop etc the shots that you don't play often.
eg marking points on the scale for flop shots that are not full power