They probably did that by keeping the bass population in check by adding a second predator (pike). The reason the bass are typically stunted is that they are stocked with panfish (bluegill, crappie, etc.) and catfish. The bass produce without anything eating them, and compete with the catfish for the panfish. Therefore, you are left with a lot of bass that can't grow due to food being a limiting factor, which is why they must be culled. In that case, humans must act as the bass predator. So it all goes back to what we both were originally saying: it all depends on the body of water (size of water, other species present, etc.)