[cpsempek]

Unsure of the exact metric you're referring to, and I'm about to be just as informal, but sports teams swing much more wildly and often than universities. In the NBA, most recently GSW, going from 5 straight finals with 3 wins to last in western conference. See also CHI before and after MJ era. LAL most recently after Kobe's retirement and pre-Lebron. In the NFL, SF post-Young pre-Harbaugh. I agree, there are often dynasties and teams can sit in the tops ranks for quite a while, however it is not at all uncommon to see once top ranked teams vying for lottery draft picks. Maybe the over-all mix does not churn that much, but I can't recall the last time a top 10 school dropped out of the top 100 without a scandal involved.

[Rury]

Generally speaking, it's just how networking/reputation works.

Talent goes somewhere -> successful things happen there -> reputation is spread -> some of that success gets associated with the place -> which attracts more talent there. Like a self-feeding loop.

Happens to pretty much every social organization - neighborhoods even. Just look at top tech companies. They attract a lot of talented tech people just because in the past talented people made those companies very successful. Conversely, if they were failures, not many people would be attracted to go there...

Anyhow, that's not to say networks can decline (as reputation also attracts less talented people). Obviously careers often span longer than sports team dynasties so it might take longer to see shuffles happen in school rankings.

[jedberg]

I would say sports just moves faster than academics. The average sports career is only a few years with a few exceptions, the average academic career is much longer.

[ghaff]

That's true and, furthermore, a big part of why a university is well-ranked in year N boils down to it being well-ranked in year N-1 and N-2. With a sports team, if you have some critical injuries or otherwise lose important personnel from the prior year or two, no one cares that you won the championship a couple years back if you have a mediocre record this year. There's just a lot more inertia in university rankings both on objective factors and on things that basically depend on being a good university because they're a good university.

[Retric]

The same could be said of students. Universities are made or broken by their recruitment, coaching/professors, administrators, and facilities. Sports may be slightly more volatile, but I doubt it’s nearly as much as people assume.