As with basketball

Mark Pesce notes,

  Jimbo has learned, through experience, that the “minor” language versions of Wikipedia (languages with less than 10 million native speakers), need at least five steady contributors to become self-sustaining. In the many wikis Jimbo oversees through his commercial arm, Wikia, he’s noted the same phenomenon time and again. Five people mark the tipping point between a hobby and a nascent hyperintelligence.