A simple trick to improve your entire fishery would be to put maximum harvest pressure on the female bluegill. Take out every single one that you can. Be relentless. This way you can never harvest over 50% of the adult fish. There will be enough males left to occupy all of the key spawning grounds which means that the smaller males will continue to add weight in order to compete next year. In a pond that is over an acre, if you keep every crappie that is under 10 inches you’ll eventually establish a small population of larger fish. I’m sure catching an 11 incher every once in a while would be a treat. Two years from now would you prefer to be catching high numbers of small bass or small numbers of big bass?