Dead center of the pin was how I've always done it or understood it . . however you're going to see absolutely zero difference in ball reaction either measuring from the center of the pin or the edge, so I wouldn't worry too much about it if I were you. 

Wow

I guess I should have just asked the question if a 34 degree Val makes any difference compared to a 40 degree Val....but then again I might have gotten a double wow

Ok here's a legit answer
Every 1 1/16" is 15 degrees in movement
Flare is predicated on pin to pap distance, which most realize
If the pin is placed in a position of higher flare potential, then a mass bias position will have less factor in influencing flare, due to already maxing out
It also depends on the strength of the mass bias...under .010 is minimal or closer to symmetrical
I was always taught, many years ago, if you were within the size of a quarter of your desired position, you were fine...
Don't over think it...surface is 70-80% in effect of reaction

Not exactly sure what that references...

I guess I should have just asked the question if a 34 degree Val makes any difference compared to a 40 degree Val....but then again I might have gotten a double wow

 Ric,

 Pretty sure its a reference to this remark..................".

Quite possibly, but then again maybe. .....just pokin a little fun.Trying to lighten up the room

Are those LED bulbs your sporting? Glad they are, because someone hit the dimmer by mistake it seems.