The division of the mountain direction and the division of the 8th house are not the same concept. The division of mountain direction is very simple, just use the door as the direction. As for the middle palace, it is the center and center of gravity of the house. For regular houses, the center and center of gravity often coincide. For irregular houses, both points must be considered, because there are also differences in the 8th house, but in both cases, things will be done.