Cam centerline question

[Verne_Frantz]

There are 2 ways to measure this. (maybe a third) I can go by I & E opening and closing points, then find the two centers, subtract and divide by 2 - OR I can find the I & E points of max lift, subtract and divide by 2.
My cam has very gentle opening and closing ramps (especially the closing side) so the opening and closing points get stretched out a lot. I'm afraid that won't be a "real life" centerline if calculated that way. Due to the late closing, I get 16deg retarded on the cam centerline.
IF I use the max lift points, I get 5deg retarded. OR............I could use opening and closing at say, .050" lobe lift.
Which would be the best "real world" way to know how to predict what rpm the cam makes its torque? Do the beginning of the ramps really have that much to do with it? I think their purpose is to just take the shock out of the lifter acceleration.

Thanks
Verne