when you have a left tear in the paper, this means that your arrow is entering the paper angled to the right. if you think about it it is like sighting in your bow, if you shoot high, move it high. if you shoot low, then move it low. so if you have a left tear, this means to move your rest to the left. considering you are a right handed shooter. this would correct the direction of your arrow travel. if you draw it on a piece of paper when you are doing it, you can see the corrections that need to be made.