I had never heard of the concept of closest average neigbor before. When I read it, I assumed it meant: draw a straight line between the two bodies, that is the

I had never heard of the concept of closest average neigbor before. When I read it, I assumed it meant: draw a straight line between the two bodies, that is the current distance between the two bodies, now average it over a couple of years of motion of these two bodies in space.