I only use live bait for smallmouth. Fished every tailrace from Watts Bar to Pickwick. I hired guides on most when learning the technique. Although the tackle rigging is a little different every single guide had strong preference for threadfin (yellowtails to the folks from bama) and totally refuse gizzard shad. When trying to catch my own I tried the gizzard with not much luck. Of course, a gizzard in the right place at the right time will get eaten. I believe a threadfin will catch 10x more smallmouth. As jp1 stated yellowtails are the best live bait on the river. But hard to get and hard to keep alive. I am retired now, 40 years and thousands of smallmouths later, I have a 100 gallon tank on my back porch. If I fish the tailraces that are hard to get threadfin, I make the trip to Jack's Bait shop in Chattanooga and buy 5-inch shiners, there is also a great bait shop below Fort Louden that I forget the name of. The big shiners are easier to keep alive on the hook and in the tank. But not as good as yellowtails for catching. I never leave home without the baitwell in my boat full. I get terribly upset when I can't get bait. I consider gizzard shad as not having bait. Maybe it is just an old man's prejudice. I have yet to catch a smallmouth that did not refuse to talk to me about it.
I have not chased hybrids very much. Ten years or so ago, I fished with a guide below Wilson. It was 0 dark thirty and we were waiting for daylight to go to the dam face to throw for yellowtail. As this guy charged a lot for a trip, he had several dozen shiners in his tank in case we could not get any threadfin. We had drifted a mile or so below the dam and heard a heck of a commotion on the surface around the boat. He told us to be very quiet saying we were in a striper school. I told him to give me a shiner. He told me that if I hooked one it would spool my line or break my rod or reel and the big girls would not hit a shiner. But hybrids are a different animal. I rarely catch hybrids although the tailraces are full of them. Maybe they don't like the big shiners, maybe I make too much noise. I have been told that a trolling motor scares them away like a stick of dynamite. Size matters (twss) I have seen people use small greenback shad (river herring) 10 inches or so and catch hybrids. You gotta match the hatch as the flyfishers say.I fish a lake in central Kentucky with an amazing population of large hybrid striped bass. They LOVE to eat shad. I am terrible at capturing shad.
A large shiner would at least approximate the size of some shad, and can be purchased at marinas all over the lake. Is there a reason that predator fish won’t hit them as readily? Maybe the different body shape?
Thanks all…