Valve train geometry

comp says
What is correct valve train geometry? When the rocker arm roller tip rolls from the intake side of the valve tip, across the center of the tip (at approximately mid-lift), to the exhaust side of the valve tip (at full lift) and back. See Diagram A.
now how is that helpful?
I've found a couple of things in the Comp literature that is bad/wrong/foolish but this takes the cake. Wow....no wonder folks are confused.