You say you know ipattern well and if you "drive" by they are where they should be. So in my opinion they obviously know you are there when you "walk" in to hunt or when sitting. Are you considering the wind direction carefully, especially from where you walk in to where they bed. Is your scent drifting right in on them so they know you are there and therefore avoid you. Consider this for both the walk in and where you sit to ambush. Perhaps as mentioned above you are fidgety when sitting They can pick off movement in a heart beat Maybe a ground blind can cover that up or a tree stand to get you above their line of site. Change your approach to your ambush spot, only hunt when wind direction is good. Turn off that AC/DC CD
Hopefully a few suggestions
Gord