Methodology

What the epicenter represents

The epicenter is the equal-season-weight geographic mean of the historically correct home playing-surface locations of the champions in the selected span. It is not the championship game site, the population center of a fan base, a measure of recruiting territory, or a claim that the named town caused the championships.

One season, one unit of influence

Every championship season contributes a total weight of exactly one. A sole champion uses that program's season location. A split-title season first collapses its recognized champions into one season point, so a split season does not count twice merely because two teams were recognized.

Two recognized champions collapse to the WGS84 geodesic midpoint of their home locations; three or more collapse to their equal-weight WGS84 Frechet mean. The 1997 season (Michigan AP, Nebraska Coaches) is the split season in this dataset.

Which champion counts

Championship rules vary by sport and era. Champography therefore publishes a sport-specific championship policy instead of pretending one rule applies to every league and century. For modern college football, the default analysis begins with the 1998 season because the BCS and later CFP systems crown a singular champion through a designated title game or playoff.

For 1998-present, the singular BCS championship-game or CFP champion counts. The 2003 AP recognition of USC is recorded but excluded by this policy; the 2003 champion point is LSU. The 2004 point is USC, whose BCS title was vacated in 2011 while its AP championship was retained; the status is recorded verbatim.

Claims that are historically relevant but excluded by the active policy remain visible in the champions record. They are labeled recorded, not counted rather than silently erased.

Historical home-location policy

The champion's primary home playing surface for that championship season, never the championship-game site, a bowl site, or a later stadium. 1992 Alabama split its regular-season home slate 3-3 between Bryant-Denny Stadium and Legion Field, so its season location is the equal-weight (geodesic midpoint) construction of the two surfaces, flagged multi_venue_equal_weight. 2001 Miami is placed at the demolished Miami Orange Bowl, its home through 2007.

The coordinate target is the center of the playing surface, not a ticket office, street address, campus centroid, or current replacement venue. When a team used multiple legitimate primary home venues during a championship season, the data record explains how that season location was constructed.

Geographic calculation

ECEF Cartesian-mean initialization followed by iterative geodesic tangent-plane refinement of the Frechet objective, with a 0.005 m step-convergence bound and a 100-iteration limit. Displayed coordinates are quantized to microdegrees (max induced error under 0.08 m).

The authoritative calculation runs offline on the WGS84 reference ellipsoid. The browser does not average latitude and longitude while the user drags the timeline. Instead, every solvable contiguous range is calculated, tested, assigned a locality label, and published in advance.

Precomputed range lookup

For a sport with n seasons, there are n(n+1)/2 inclusive contiguous ranges. Champography stores one result for each solvable range. That makes slider movement a local, constant-time lookup and eliminates runtime geocoding, database queries, and server-side calculation for historical views.

Each published result carries the champion dataset version, source-data hash, algorithm version, locality dataset version, range status, and basic dispersion measures. A range is not quietly published as complete when a champion location required by the policy is unresolved.

Town and locality labels

Labels resolve offline against the GeoNames cities1000 populated-place gazetteer (CC-BY 4.0). This release emits qualified nearest-place and rural-area labels only; it never claims that a point lies inside a municipal boundary, because polygon containment data is a documented deferred input. Bearings read from the named place toward the epicenter.

The numeric coordinate is the authoritative result. The town name is a human-readable label produced by a separate resolver. This distinction matters because a point can lie outside an incorporated municipality even when a nearby city is widely recognizable.

Uncertainty and interpretation

Mean, median, RMS, and maximum geodesic distances from the epicenter to each contributing season location. The epicenter is a mean, not evidence of clustering.

A single mean point can result from a tight regional cluster or from distant locations that balance one another. Champography therefore reports the number of contributing seasons, unique programs, mean distance, median distance, and maximum distance alongside the point. Those measures describe spread; they are not a formal confidence interval.

Quality controls

• Every expected season is present or explicitly classified.
• Every counted claim links to a season, team identity, venue, and source record.
• Venue dates are checked against the championship season.
• Coordinates are validated and tested against venue-city sanity bounds.
• Every precomputed range is compared with direct recalculation test vectors.
• Published artifacts are deterministic and content-hashed.
• Python and TypeScript implementations are parity-tested within defined tolerances.

Current release

Dataset

2026.1

Coverage

1992–2025

Algorithm

wgs84-frechet-v1

Locality resolver

nearest-place-v1

Range records

595

Champion data hash

sha256:f010689f65d6da10c99e0cd3e3a0d6aaab3d1722db2c96b6fff3b095219d478b

Current limitation: Coverage begins with the 1992 Bowl Coalition season. Pre-1992 eras are configured but disabled pending the historical dataset extension. The public site identifies this boundary rather than presenting the available window as complete all-time history.

Independence and corrections

Champography is an independent analytical project and is not affiliated with, endorsed by, or sponsored by the NCAA, the College Football Playoff, any conference, league, team, school, or venue. Sources do not control the interpretation or the calculated result.

Material corrections are versioned, rebuilt through the same pipeline, and documented rather than edited silently in the browser.