as for this little subject.
It is my understanding that all beings have a relationship with the force, but only certain beings are born force sensative, this seems to be genetic. As for how the midis work, i realy dont know, but would assume the higher your count is the great probablity you would be force sensative.
I hate the PT version myself. Yoda speech about the nature of the force is wonderful, where as qui gons musings over medicalorian counts is terrible. sad sad sad it is...