ORIGINAL: r33h
We have determined that there is actual contact because he uses green fletchings and the fletching is turning the forks on his drop away green from brushing past. As to how high the nock point is on the string from center...I am not sure. Could you explain a little more on what you mean by this question? If I am thinking correctly on this question, I believe you are wanting to make sure that the arrow is ninty degrees perpendicular to the string when nocked and when the arrow is resting on the arrow rest in the "up" position...is this a correct take on the question? If so, I am pretty sure that the arrow is square to the string (I will need to double check though).
I would actually have that nock about 1/8-1/4" above being level. Otherwise the nock travel throughout the draw/release cycle may slam the arrow down and into the rest. This is important on single cam bows, you get more nock travel throughout the cycle than in a properly timed dual, or a binary cam.