I learned that doing what other hunters won't usually do because of the extra effort required will sometime get you the bird. Ex. Hunted the Black Hills for two days with the same results that the other hunters were having - Birds would answer and them go the other way! Decided to try a different tactic - took an hour to climb to the top of a small mt. and worked my way down from the top. On the trip down I had a Tom goobling like crazy below me in the first five minutes. He was headed in and I went to set up and rolled a rock from under my foot and the Tom departed. Tem minutes later another Tom answered and was coming hard. This time I got set and he steped into view at about 10 yds. and I thumped him.
I believe my making the effort to do something that required extra effort was the reason for the change. I have found that road side Toms will respond differently when I circle and approach from the side away from the road.