the more coarse the hair the better. the bigger the volume of hair, the bigger the chances are that it is going to shut out the reflection of light from the scalp and look like a full head of hair. the reflection of light from the scalp through thin hair (therefore light reflecting in-between low calibre hair shafts) creates the perception of hair loss. for every 10 microns increase or decrease in the hair shaft calibre, there is a 35% volume effect, either way. the average persons’ hair shaft calibre is around 68-70 microns. if for example, the calibre goes down to 58 microns, then literally 36% of the persons’ hair volume gets lost
this being sad other factors such as skullsize play also important role. when you say "I have seen results with patients who have had half the number of grafts from the same surgeon yet achieve superior results than patients who have fine hair." id take this with a grain of salt. people can be the same norwood level but the area which has to be covered can vary drastically due to different skullsize and shape
nontheless the ideal candidate for a haitransplant is probably and indian person with a small skull, quiet coarse hair and a low hair-to-scalp contrast