The deer i shot last year had an arrow stuck in its neck (not my own).
Need i say more??
You can practice all you want brother but this sport is not archery, its bow hunting, and when your bowHUNTING stuff happens, you may look through a twig and not see it, causing a small deflection, or you just may pull off a bad shot. I know were not all as perfect as you but come on, you owe it to the deer to go for the highest percentage shot.