The folks at The Washington Post have jumped on an idea of mine from two and a half years ago: greatest teams never to win a championship. (See here.) Chris Rukan considers the Nationals of the past seven years versus other teams over such a period. That piece is here, limited to baseball and going back only to 1969, the first year of the League Championship Series.
Rukan identifies seven teams with better overall records than the Nats who didn’t win championships. The Nats, however, are the only team with the sad distinction of never winning even one playoff series.