O.K. I'll take another shot at this
Lets say that when the reluctor is lined up with the pick up, a spark shoots out of the coil.(it may happen on the rising edge or falling edge, but lets make this easy)

When the distributor is at rest, and the pick up and reluctor are lined up with each other, the rotor is aimed dead center at the cap terminal.
I have the distributor here and I see this as true.

Now lets add 10 (distributor)degrees of mechanical advance.

This seems to be where everyone starts to disagree.

The way I see it: The coil will only fire when the reluctor and pick up are aligned.

The way some see it: The rotor is 10 degrees ahead of a cap terminal when the spark occurs.

Since a spark only occurs when the reluctor and pick up align, how can this be?

How is the spark triggered if the reluctor is not in line with the pick up?