The circuit is the collective name for the group of schools and teams that regularly participate in weekend quizbowl tournaments. By general consensus, "the circuit" does not include CBI-only schools or high schools that only participate in local quizbowl leagues. When referring to the circuit or one of its divisions, it is proper to call it by its name of "the circuit" or "the [insert geographic division here] circuit", and never just plain "circuit".
Divisions of the Circuit
Due to obvious geographic restrictions, "the circuit" is divided into several more-or-less autonomous areas, each of which is nevertheless connected by common national tournaments the teams that travel outside of their primary area.
The College Circuit
The college circuit is divided into the Northeast, Mid-Atlantic, South, Midwest, Southwest, West Coast, Pacific Northwest, and Canada circuits.
The Northeast Circuit consists of teams in New England and New York. The nominal center of this circuit is the Boston area. Tournaments in this circuit often end early or are cut short due to many teams' need to take limited-hours public transportation back from the tournament.
The Mid-Atlantic Circuit consists of teams in Pennsylvania, New Jersey, Delaware, Maryland, Washington DC, and Virginia. Were there actually quizbowl-playing colleges in West Virginia, they would most likely associate with this circuit. To a lesser extent teams in New York and North Carolina belong to this circuit, though they are primarily associated with other circuits. The nominal center of the Mid-Atlantic Circuit is the DC area, in particular Maryland.
The Southern Circuit consists of teams from Kentucky, Tennessee, North Carolina, South Carolina, Mississippi, Alabama, Georgia, and Florida. Although more associated with the mid-Atlantic, some Virginia schools also associate with this circuit. Due to the vastness of the circuit and number of teams on the circuit, tournaments are occasionally held in both the South and "mid-South" (traditionally Kentucky, Tennessee, and to a lesser extent North Carolina and Virginia). The nominal center of the Southern Circuit is Chattanooga, largely due to the myriad tournaments run by Charlie Steinhice and UT Chattanooga.
The Midwest Circuit consists of teams in Minnesota, Iowa, Missouri, Illinois, Wisconsin, Michigan, Indiana, and Ohio. Teams in the western part of Pennsylvania often associate with this circuit, and any possible quizbowl-playing schools in the Dakotas would likely associate with this circuit as well. Due to the number of teams associated with this circuit, it is occasionally divided into the "North" (primarily the schools on or west of the Mississippi River) and "Great Lakes" (primarily the schools east of the Mississippi) circuits. The nominal center of the Midwest Circuit is Chicago, which in addition to hosting many regional tournaments hosts the premier masters tournament in the nation, the summer Chicago Open. For a time the Midwest Circuit was the epicenter of the so-called difficult packet movement. Due to its roughly central location, at least one national tournament is typically held each year on the Midwest Circuit.
The Southwest Circuit consists of teams in Texas, Oklahoma, Kansas, Arkansas, and Louisiana. Teams in Mississippi and Missouri occasionally associate with this circuit as well. Due to being ridiculously spread out, nine hour drives to and from tournaments are not uncommon, and there is no true "center" of the Southwest Circuit.
West Coast Circuit
The West Coast Circuit consists of teams in California and any extant teams in Arizona, Nevada, and Utah. There are two nominal centers of the West Coast Circuit, the Bay Area and the greater Los Angeles area, which are separated by roughly a six to eight hour drive.
Pacific Northwest Circuit
The Pacific Northwest Circuit consists of teams in western Canada as well as any extant teams in Washington, Oregon, and the rest of the northwest U.S. The nominal center of the Pacific Northwest Circuit is Seattle. Since 2008, the circuit has grown thanks to teams like University of Washington, Boise State and Gonzaga University.
The Canada Circuit consists primarily of teams in Ontario and Quebec. The nominal center of the Canada Circuit is probably the Toronto area.
The High School Circuit
The high school circuit is largely divided into a separate circuit for each state, although there is substantial overlap between circuits on the east coast (thus the creation of a "DC area circuit") and California is divided into the Northern California and Southern California circuits. The nominal head of each circuit is probably the person in charge of whatever association governs quizbowl in that state, with the exception of states that have no unifying association. Note that in states that have archaic circuit rules like Alabama and Missouri, the best-known member of a state circuit may have little to no connection to its nominal head.