There are plenty of candidates for longest suffering American sports fans. Chicago Cubs fans held the title by acclamation until the World Series win of 2016. The Seattle Mariners have the longest streak without postseason play. The Buffalo Bills get sympathy for their four straight Super Bowl losses.

But for real anguish, consider the St. Louis Blues.

Immediately after joining the N.H.L. in 1967, the Blues made three straight Stanley Cup Finals. But they have not been back since. That’s 48 years of frustration, despite suiting up Hall of Famers like Brett Hull, Chris Pronger, Al MacInnis and Bernie Federko over the years.

Now, after coming back from a three-games-to-two deficit against the Dallas Stars and winning Game 7 in double overtime on Tuesday night, the Blues are one series away from that elusive Stanley Cup Finals.

Their appearances in three straight finals as an expansion team back in the ’60s may seem like an incredible feat. But it occurred because of a quirky decision by the N.H.L. The original six teams were all placed in one division, the East, while the six new teams were placed in the West, no matter the geography. So for three years an expansion team was guaranteed to make the finals.