Fastest 1st-worst-1st or worst-1st-worst

[Duke]

My adopted county cricket side, Glamorgan, were last in the entire County Championship in 1994, won the Championship in 1997, and were last again in 2007.

If there’s a county that managed that trifecta in fewer than 13 years, I don’t know of it.

[DSYoungEsq]

@RickJay

I thought the OP was pretty clear.

In baseball, for first-worst-first, I’m sure it’s got to be the Twins, who did it in a span of five seasons from 1987 (World Series champions) to 1990 (last place) to 1991 (World Series champs again.)

(A noteworthy bit of trivia is that both competitors in the 1991 World Series, the champion Twins and NL champ Braves, had finished last the previous year. The Braves, however, hadn’t won a championship in many years so don’t qualify for the OP’s challenge.)

For worst-first-worst, the Marlins have already been cited, having gone from last in 1994 to World Series champions in 1997 to dead last again in 1998.

<sigh> The Twins were already cited. But they don’t count, because they weren’t the worst in MLB.

[Cugel]

@mrpayday

In the NSW Rugby League South Sydney managed to go from 1st to last in one year.

1989 18 wins 1 draw 3 losses
1990 2 wins 20 losses

To satisfy the OP (Ameri-centricism aside), Penrith last in 2001, Minor Pemier 2003, last 2007.

Canterbury MP 1942, last 43 & 44, MP 1947.

[Cullain]

Miami Heat had the worst record in the league in 88-89. Won the championship in 2006, and had the league’s worst record in 2007-2008. It’s a 19 year gap, but I don’t believe any other NBA team has ever gone from worst - champion - worst ever.