How is cut angle related to ball-hit fraction?
Illustrations, equations, plots, and numbers on this topic are available here:
Here’s a useful illustration from “Aim, Align, Sight – Part I: Introduction and Ghost Ball Systems” (BD, June, 2011) defining the standard ball-hit fractions:
For more information and demonstrations, see the fractional-ball aiming resource page.
from Bob_Jewett (from AZB post):
Here is a plot of the cut angle you get versus the fullness of hit. For example, a fullness of 0.5 — an exact half-ball hit — gives a cut angle of 30°. (This ignores throw which can be several° depending on speed, spin, cut angle and ball conditions, but that is mostly a separate issue.) A couple of other fullnesses to note are 3/4 full which gives an angle slightly under 15° and 1/4 full which produces about a 48° cut.