h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Does anyone know the answer to this? Its been bugging a few of us at work for a while now and noone knows the answer:

Liverpool haved done it more times than anyone else. Manchester united have only done it once. Arsenal can only do it if Arsene Wenger leaves. Crystal Palace and Oldham Athletic have also done it.

All we can think of is that it might be something to do with groud sharing or playing at a ground that used to be owned by someone else or something in that vein.

I reckon its that they have appointed an ex-player as their manager

Hmmm. Could be but surely almost every club has done that at some point. Was Matt Busby the only ex-player to manage Man U?

hmmmm ... this is a toughie!

Are these the only clubs to have done IT?

Not sure, sorry. I would hope so or the question is really hard.
Believe me, we can't get it here and there are some serious Statto's knocking about. Just thought someone here might know.

I too think it's something to do with ground-sharing or playing elsewhere, but can't quite remember. In the case of Arsenal & Arsene Wenger would it be something to do with playing at Wembley? That said they've already tried that.