Because your eye is about 9 inches are so above your arrow. The closer your eye is to the arrow the less differences it would make. If you take a string, hold it up and the top is your eye and the bottom is the arrow. The eye will all ways be in the same spot, so move the bottom of the string the arrow and how you can see the arrow is how to the right are lift, so you can see the arrows going hit right are lift not straight under your eye when it's level. The farther away the target is the farther right are lift it is going to be. You can cant your bow if you cant the same ever time with your 4 are 5 pin sight like the string need to be in leveled up straight under your eye, not level with your bow. The sights would need to be sat level with your eye in order not to walk off the target to one side at longer yardage.