In the last 20 years only one team has won back-to-back Stanley Cups.
The Pittsburgh Penguins' Cup Final victory over the Nashville Predators in 2016-17 marked the first time since the Detroit Red Wings won championships in 1996-97 and 1997-98 that a team raised the Cup in consecutive seasons.
Making two straight appearances in the Cup Final is slightly less rare. Pittsburgh and Detroit played each other to decide the 2007-08 and 2008-09 seasons, and the Dallas Stars competed for a title in 1998-99 and 1999-2000.
This season, the Washington Capitals have the look of a team that could make back-to-back Cup appearances into a trend.