At any given time, not many more than half of the managers in the Premiership and Football League have been in their current positions for more than a year. This has been the state of affairs for no less than several years now.
Halfway through the current season, 25 clubs have so far replaced or removed their managers.
The pressure to succeed is very great, and increasing all the time.
Currently, only 21 managers have been in office 2 years or more. Long serving managers such as Sir Alex Ferguson and Arsene Wenger are by far the exception.
What is apparent is that clubs which have kept the same manager for 3 or more seasons have either been successful or made good progress during the tenure of that manager.
Whether a manager is any good or not, if the chairman and the board decide within a year of appointing him that he is so bad that he should be sacked or replaced, why was he appointed in the first place?
It is more likely to be the case that the fit between the manager and the club was not right in the first place. That is the responsibility of the chairman and the board. The process by which the manager was selected should be the first to be questioned.