Ok.. so if, for example, your 10th fret is too high and you use a fret rocker it should only rock when centered on the 10th fret. I get that. But if the 10th fret is too low a fret rocker should rock on the 9th and 11th frets. What are the odd of both 9 and 11 being high vs 10th being low? Am I over thinking this?