Stanley Cup Champions Since 1915:
Average Location of Stanley Cup Champions Since 1915:
The average locations were created using a window function in PostgreSQL. We can utilise the geography type to take into account the curvature of the earth and make the calculation on a spheroid.
So for the average location of the last five years:
select id, ST_Centroid(st_collect(geom) over (ORDER BY id ROWS BETWEEN 4 PRECEDING AND CURRENT ROW)::geography, True)::geometry as five_year_cent from nhl.winner_1915