The world of management is full of constant movement with sackings and appointments as commonplace as player transfers.
However, like the players they manage, there are a chosen few that stand head and shoulders above the rest.
Wherever they go, they find success and will never be short of a job offer should one chairman grow impatient.
The likes of Arsene Wenger, Jose Mourinho, Sir Alex Ferguson and Jupp Heynckes have defined a generation but they will soon be gone and will need replacing.
Here we look at 10 managers under the age of 50, who are the likely heirs to their wrinkling masters.
Have we missed anyone glaringly obvious? That's why we have a comment box! Let us know your suggestions. Remember, they've got to be under 50!