NBA
Championship eras
Era presets are tied to structural changes in the rules or the league's membership. They are not arbitrary decades and they are not defined by which franchise happened to win.
Default analytical range
2004-05–present
30-Team Era
The league has had its current 30 franchises since the Charlotte Bobcats began play in 2004-05.
The analytical default, because league membership and playoff structure have been stable throughout. It is also the era of the Warriors' and Spurs' repeat titles, which pull the point west.
Era definitions
Pre-Shot-Clock Era
The BAA's founding seasons and the early NBA, played in a compact northeastern and midwestern footprint before the 24-second shot clock arrived.
Several champions of this era — the Philadelphia Warriors, the original Baltimore Bullets, the Rochester Royals, the Minneapolis Lakers — either folded or later moved, so the map shows cities the league no longer occupies.
Boundary basis: BAA founding in 1946-47 through the last season before the shot clockShot Clock Era
The 24-second shot clock arrived for 1954-55 and the league settled into a small, stable set of franchises — the period of Boston's eight straight titles.
The epicenter here is dominated by one dynasty; it describes where the league's winning was concentrated, not where the league was evenly distributed.
Boundary basis: Shot clock introduced for the 1954-55 seasonABA Rivalry Era
From 1967-68 to 1975-76 the rival American Basketball Association competed for players and markets while the NBA expanded west.
This span includes the Lakers' first Forum title, Milwaukee's 1971 championship, and the geographic broadening that expansion produced.
Boundary basis: ABA play began in 1967-68 and ended with the 1976 mergerPost-Merger Era
The three seasons between the 1976 ABA merger and the arrival of the three-point line, which absorbed four ABA franchises into the NBA.
A short preset, useful mainly as the boundary between the rivalry years and the modern scoring era. Its champions — Portland and Washington — are two of the league's rarest.
Boundary basis: ABA merger in 1976; three-point line added for 1979-80Three-Point Era
The three-point line arrived for 1979-80, spanning the Magic and Bird rivalry, the Jordan dynasty, and the league's growth toward 29 teams.
The longest preset in the dataset. Its epicenter reflects a genuine coast-to-coast distribution of champions for the first time.
Boundary basis: Three-point line introduced for the 1979-80 seasonThe BAA seasons, and franchises that moved
The first three championships on this timeline (1947, 1948, 1949) were won in the Basketball Association of America, which merged with the National Basketball League in 1949 to form the NBA. The league counts those titles as its own, so Champography counts them too.
The NBA has relocated more championship-winning franchises than any other league in this project, and the map follows the champion to the city it actually played in. The Lakers appear in Minneapolis for five titles before Los Angeles; the 76ers appear in Syracuse for 1955; the Warriors appear in Philadelphia, then Oakland, then San Francisco; the Hawks won their only title in St. Louis; the Royals won theirs in Rochester. Two cases needed an explicit decision, both recorded in the champions table: the 1948 Baltimore Bullets are treated as a defunct franchise unrelated to the modern Washington club, and the 1979 SuperSonics title is credited to the franchise that became the Oklahoma City Thunder, with Seattle's retained heritage noted.