At least half the time that I've shot deer while still-hunting in heavy cover the deer were either alert to my presence or already hauling ass to get away from danger.
I hear this over and over. It's the biggest reason why a rifle with rapid repeat fire capabilities is preferred for still hunting. If you're doing it right, you should be spotting most of the deer before they see you. If you're mostly seeing tails, you know you're doing it wrong. Most of your shots should not be hurried or at running deer. The truth is, most guys absolutely suck at still hunting. They move too fast, make too much noise, don't pay mind to wind direction, stop in the open to look around and don't use binoculars to effectively see into/through cover.
