Crappie don't outproduce bluegill, they outcompete them. Both of those species are predator fish, limited by mouth size. Since crappie have a larger mouth, they can eat larger prey. My experience with crappie reproduction is that it isn't predictable. We never know if they'll spawn each year. But, when they DO spawn, they are first in warmwater ponds. Their babies can easily outcompete baby bluegills...heck, they can eat baby bluegills. The biggest problem with crappie in small ponds is the fact they overeat the food chain at a critical link in the chain. With mouths smaller than bass, crappie eat lots of small meals. Those small meals never get the chance to become larger meals, which means a significant part of a developing food chain disappears before it gets the chance to become significant for intermediate and larger fish.
Will overcrowded bass control crappie? I expect they would, for a while. The dynamics of overcrowded bass dictates a fight for food. So, not only will overcrowded bass help control crappie, they'll eat them, too. Plus, overcrowded bass eat similar food items that larger crappie eat. So, they compete. That's another reason to expect crappie to stunt. It ain't easy to compete with big numbers of skinny bass.
