I'm no engineer, but I hardly see how that would make a difference. Physics are physics, and the dot on the end of the pin is in the same place regardless of whether it's mounted on a verticle or horizontal pin. The reason you shoot high out of an elevated postition is twofold. First, line of sight distance is not actual yardage. You being higher in the tree makes you "farther" from the deer than you actually are. Distance is added by height, but you really aren't any farther away. I didn't word that very well, but I know what I mean by golly....[&:]

In other words, actual distance is the distance from the BASE of the tree to the deer, not from YOU to the deer. Also, gravity has a different effect if you are shooting down as opposed to horizontally. It doesn't lose horizontal altitude as quickly therefore you shoot high. Holy cow, I may have just confused myself. [&:]