I've kind of thought that they meander their way north following bait and temperature ( near shore ) and then in the fall they tighten up and screw south more quickly. Also tend to be a little more offshore in the fall.
We used to finish our season with a charter a long way south of nantucket in mid november and the water would be black with nice bass in those far away offshore rips. Great fun as long as you weren't on the camcorder.
just an old farts two cents