This sounds like they are reversing the likely cause-and-effect:<p>"Even in larger teams, high-impact teams have core and support cadres. A small number — sometimes just one — of the team do the majority of the work, while other, non-core members act in support roles."<p>Successful projects will tend to bring in a larger number of contributors, most of whom will only make a few contributions. So successful projects will tend to have this pattern. But it is the success of the project that creates that pattern, not the other way around. Lots of projects are not successful, so no one ever contributes to them.