I used to try to put the bullet or arrow right behind the shoulder and not quite halfway up the body but I have killed enough to know that the higher up in the vitals the poorer the blood trailmight be. What I mean is the same shot a little lower seems to leak more blood. My firstbow kill was a perfect double lung shot and I saw her fall and its a good thing because after I recovered the deer I went to follow the trail and therewas no, I mean not a drop of blood on the ground from the arrow for 50 yards where she piled up. I think you hit the nail on the head when you said hit the opposite shoulder on a quartering away shot. In fact I aim for the opposite side of every deer I shoot, it forces me to pick a spot. But please too anyone who reads this I have have found deer for myself and other hunters that "missed". Half a day on your hands and knees is no fun but it beats the long walk back to the truck with that horrible feeling in your gut. D.