While all the elements of good form can get complicated, let's not lose track of the fact that if all forces are straight forward and straight back, the arrow will always go in the direction of the forces. If you line up your eye with the forces, the arrow will go where you're looking. Push directly toward the target, pull directly away from the target, put your eye over the arrow, eliminate forces in any other direction, and you will always be on line with the target. When you miss, what kind of force did you introduce that was out of line with the target? Did you move your eye away from over the arrow? Did you give a slight off-line jerk as you released the arrow? Did you torque the string or the bow? Learn to be aware of these forces and you won't have to read anything I or anyone else has to say on back tension or anything else.
I think we sometimes use an intellectual understanding of something as a substitute for the real thing, and I am as guilty of this as anyone else. I enjoy using my mind, but I will have to admit that I would probably be a better shot if I thought about things less and learned to be more aware of what my body is trying to tell me on a physical level.