I worked the numbers for each league to identify teams that have never won and the team that has gone the longest since winning.
A third idea: How many teams in each league are in the midst of “historic” droughts. As I said, we have no clear line past which a gap becomes “historic.” It may depend on other factors: Team history matters; a +15-year gap for the Celtics or Yankees differs from a +15-year gap for, say, the Pistons or White Sox). Or consider how often a team came close without winning. Of course, that can cut in either direction–would you rather be a Bills fan (62 years, but four Super Bowl losses, including “wide right,” and some other stunning playoff defeats) or the Browns (62 years, a few stunning playoff defeats, and years of awfulness).
For present purposes, I will set the line at 40 years. This seems a reasonable line, in which multiple generations of fans have suffered–Fan X is 13 (peak fandom) when the team win the title in Year I; over 40+ years, Fan X has suffered the failure with his grandparents, parents, and children old enough to have invested in the team, as well (perhaps) as great-grandparents and grandchildren. Plus, this will make Mets fans happy, as they can enter long-suffering fandom come November (assuming they do not win this year). For those who want a higher line, you can see the smaller group in the later threshold.
So here goes:
MLB (4 teams):
• Tigers (41 years)
• Orioles (42 years)
• Pirates (46 years)
• Guardians (77 years)
NFL (9 teams):
• Bears (40 years)
• Raiders (42 years)
• Dolphins (52 years)
• J-E-T-S Jets Jets Jets (57 years)
• Bills (62 years)
• Browns (62 years)
• Titans (65 years)
• Lions (69 years)
• Cardinals (79 years and two cities ago)
NBA (6 teams):
• Sixers (43 years)
• Wizards (48 years)
• Nets (50 years)
• Pacers (53 years)
• Hawks (68 years and one city ago)
• Kings (76 years and three cities and a name change ago)
NHL (3 teams):
• Islanders (43 years)
• Flyers (51 years) (like the ’70s Knicks, the ’70s “Broad Street Bullies” remain city icons)
• Maple Leafs (59 years)