One thing to keep in mind is there are different kinds of rubs. If I were going to hunt rubs, I would hunt a rub that has been used for a few years. Most of the time, these rubs are used by a number of deer.
I am hunting this deer now. I have my stand set up on his rub line, but as stated above, his rub line is from his bedding area to where he is feeding. I had an encounter with him last week, but he was not walking his line. He came in down wind of it. I have my stand set up b/c its b/t his feeding area and bedding area, not b/c his rub line also comes through my area.
As for scrapes, most scrapes are made and never returned to. I have read alot that says that deer may scent check scrapes from a distance.
My advice for you would be to do some more scouting. Try to find where the deer are bedding. I have had 17 deer, all within 30yds of me, in the past two weeks. I found a great bedding area and a good spot that I can get high and the wind seems to favor this spot most of the time.
