NHL
Stanley Cup eras
Era presets are tied to structural changes in who could compete for the Cup and how the league was organized. They are not arbitrary decades and they are not defined by which club happened to win.
Default analytical range
2005-06–present
Salary Cap Era
Since the lockout the league has operated under a hard salary cap, the structure that still governs how contenders are assembled.
The analytical default, because the rules that shape a champion have been broadly stable throughout.
Era definitions
Inter-League Cup Era
The Stanley Cup was not an NHL trophy yet. The league's champion met the champion of a rival western league, so a club outside the NHL could win it — and in 1925 the Victoria Cougars did.
An epicenter from this period reflects a genuinely continental competition, with Ottawa, Toronto, Montreal and Victoria all in play. Several of these champions no longer exist.
Boundary basis: First NHL Cup win in 1918 through 1926, the last year a non-NHL club competed for the CupNHL-Exclusive Era
From the 1927 Final onward only NHL clubs competed for the Cup, through a period when the league expanded into the United States and then contracted through the Depression.
The map moves south and west here for the first time, as New York, Boston, Chicago and Detroit begin winning.
Boundary basis: First all-NHL Final in 1927 through the last season before the Original SixOriginal Six Era
Twenty-five seasons in which the same six clubs played for the Cup every year: Montreal, Toronto, Detroit, Boston, Chicago and New York.
The tightest geography in the dataset, and the most concentrated: Montreal and Toronto took 19 of the 25.
Boundary basis: Brooklyn Americans suspended operations in 1942; expansion doubled the league in 1967Expansion Era
The league doubled in 1967 and kept growing, absorbing four WHA clubs in 1979 and carrying the Cup to Philadelphia, Long Island, Edmonton and Calgary.
The widest swings in the dataset. Montreal still won nine, but Edmonton's five and the Islanders' four pull the point in opposite directions.
Boundary basis: 1967 expansion from six to twelve teams through the last season before the Canadiens' 1993 titlePre-Cap Modern Era
Sun Belt expansion and unrestricted free agency reshaped the league between Montreal's last Cup and the lockout that cancelled a season.
The era in which the Cup first went to Dallas, Denver, Raleigh and Tampa — the sharpest southward move in the sport's history.
Boundary basis: 1992-93 season through 2003-04, the last season before the salary capWhere this timeline starts, and why
The Stanley Cup is older than the NHL. It was first awarded in 1893 and spent its early decades as a challenge trophy contested by clubs from several leagues. This dataset begins with 1917-18, the NHL's first season and the first Cup won by an NHL club, because that is where a continuous, consistently documented championship record starts.
It does not begin with an NHL-only record, though. For nine seasons the Cup was still contested between leagues, and in 1925 the Victoria Cougars of the Western Canada Hockey League won it — the last club outside the NHL ever to do so. That title is counted here, because what this dataset tracks is the Stanley Cup rather than the NHL playoff championship. Each claim records whether the winner was an NHL member, so the alternative reading stays available in the data.
Two seasons crowned no champion at all and remain on the timeline carrying no weight: 1918-19, when the Final was abandoned tied during the Spanish flu epidemic, and 2004-05, cancelled by a lockout. The Cup is physically engraved with both facts, and dropping either season would quietly distort any span that crosses it.