During World War II, the competition was put on hiatus; the last pre-war winners, Birmingham Athletic Institute, retained the trophy for the duration of the hostilities.
[2] This structure continued through the introduction of the independent, franchise-based British Basketball League in 1987, though the cup was eventually truncated to a 16-team event for 1998 onwards, with the clubs holding a BBL franchise being joined by the top teams from the previous year's NBL Division 1 standings.
These changes led to conflict with the British Basketball League, which withdrew the support of all top-flight clubs and started their own breakaway competition.
[3] The withdrawal of the top-flight clubs led to the National Cup returning to a more open structure, with teams able to enter from all divisions of the NBL.
The current competition structure is a knockout tournament with pairings drawn completely at random – there are no seeds, with the draw for all the rounds up to and including the quarter-final taking place in May.