Some managers seem to get jobs in the top flight despite their abilities. This baffles me why the same group of managers are employed over and over again.
I remember when Bryan Robson had been given the managerial role at West Brom (I think) and some pundit had said "if anyone can keep them up, Bryan can". This was the man who managed Middlesbrough, the (then anyway, I don't know if this has changed) most expensively assembled team to have been relegated.
Most of his career as a manager has been embarrassing, but he actually did keep the Baggies up. It's one of the few times (perhaps even the only time, I don't know) that the team which was bottom at Christmas didn't get relegated at the end of the season.