Mcbroom is correct, everything has to work perfect to get both sides the same, string down the center, grip the same and you have to grip it the same, plus shoot it the same. all in all a challenging thing to pull off, but over time it all comes together. I found that hard aiming point on was key to addressing left and right hand form variances. I have two, I was told that one slightly favors one side. I cannot see it, but neither can I tell with my arrows, they fly the same and aim the same. It concerned me a bit at first, so I went out and did some long target shooting with new aluminum arrows to see what would show up at hard aiming at point on. Nothing was different, my point on was the same on both sides, neither left nor right issues, 54 yards with those particular arrows. Perhaps 56 with three fletch cedars and 52 yards with 5" four fletch Surewoods, still no left or right issues. The Surewoods and the aluminum arrows were the same weight, just the fatter shaft and one extra feather. I do not know how common it is but my wood arrows come out with extreme consistency with weight. I sanded about five grains off of only three of the two dozen to get them within a couple grains of the others.