Mainstream quizbowl

Mainstream quizbowl consists of teams which are permanent enough to hold regular practices and compete in Saturday tournaments featuring academic content. Implicitly, such teams are affiliated with a school - active players who have graduated are often considered part of the parallel open circuit. Not included in this category are participants in other formats, those who play inappropriate difficulties, and those who play predominantly pop culture questions.

Tournaments played in mainstream quizbowl are produced by NAQT for all levels, by ACF for the collegiate level, and by various members of the community for various target difficulties in the case of housewrites. These three groups have gradually taken over market share from question providers which do not adhere to the principles of "good quizbowl" and the need to distinguish between mainstream and non-mainstream quizbowl has consequently declined.

High school

In high school quizbowl, most teams in the mainstream play NAQT sets. Common examples are IS and IS-A sets, which are played by hundreds, if not thousands, of teams across the nation. NAQT has also become the provider for the state formats like Virginia, Illinois, and Missouri (though they reverted to Academic Hallmarks in 2021), which are thus considered to be part of the mainstream as well.

There are also schools which primarily play in after-school leagues or televised competitions or do other academic extracurriculars like Academic Decathlon. Teams from these schools that do attend mainstream tournaments are often recruited on a one-off basis and may simply be a collection of top students with no preparation.

College

In collegiate quizbowl, the implosion of the College Bowl campus program means that the majority of teams are part of the mainstream community. There remains the Honda Campus All-Star Challenge, which targets historically black colleges and universities, as well as the recent revival of the College Bowl televisions how; however, the latter does not involve enough teams to be considered a major alternative. The phenomena of trash capture and of teams playing exclusively NAQT high school questions have largely died out, though there are still sporadic accounts of schools hosting tournaments on IS sets.