It all has to do with noise of bow, felt impact, shot placement, and the deer's sense of awareness at impact...ie..A deer that had been meandering through an oak ridge eating acorns gets smoked by a VERY quiet bow with a VERY sharp Bhead through the center of the lungs will run way less distance than a deer that got driven or bumped to a hunter that shoots an unsilenced dual cam with vortex heds and hit the same spot.....