David Moyes will be in a familiar dugout tomorrow evening when West Ham take on Everton.
It is his third visit to Goodison Park with a new club, following unsuccessful trips with Manchester United and Sunderland.
Allardyce was the manager of West Ham between 2011 and 2015.
This crossed over with Moyes' stint at Everton from 2002 and 2013.
If you had suggested that between 2011 and 2013, Moyes and Allardyce would end up swapping jobs a few years later, you would have received funny looks and a few choice remarks from supporters.
Even just a few weeks ago, David Moyes was hardly the popular choice for the West Ham job.
Two games into the role, supporters are open minded but yet to be convinced.
The prospect of Everton handing the keys to Allardyce seems even more unlikely, but it suddenly seems like a real option, which is reflective of their worrying league position.
Moyes was previously derided by Everton fans after his failed spells elsewhere, while Allardyce was fired by West Ham.
Now both could have the chance to re-write their own legacies, in unlikely circumstances.