Also I would say that KNOWING the land you are hunting plays a big part in it. which goes with what Eric said.
Yeah, that helps too, it seems like the hogs like to hang out in a few spots time after time. Also, something Ive wondered, a few places I hunt, when the hogs run, 95% of the time, they run to the same place. I know it must be different hogs, I just cant figure on how they know to run SW instead of NE or some other direction