Jumps were more often and sustained longer when the lake was primarily threads and gizzards so I think this is the hammer hitting the nail dead on the head. Keep in mind, these feeding battles usually start down in deep deep water and work its way to the surface. I don't think stripers can herd alewives from underneath as well as they can herd threads. I think they have more success herding alewives from the side better. Many of the jump action today comes as predatory fish pin the bait next to a bank pocket or bluff. Used to, it would happen over open water and many times it was the size of a football field. I have seen that a few times but I would think it happens when threads are schooled. As a side note, I've found that sometimes you can get largemouth, Kys and smallies all mixed in with the stripers this time of year when the bait is pinned to the bank mid creek back or better.

I have found that casting to an area that recently had pinned jumps can still get bites for another few minutes this time of year. Two years ago I picked up four fish on a red fin by continuing to cast after the jumps went down. Mind you it was four fish from four different jumps so I got one each time. And they were all smaller, but it was still a blast!