Sacking a manager is a very expensive business, that is one of the reasons that our Board have worked in the way they have with both Sousa and Laudrup, with Sousa they got lucky, with Laudrup they didn't, but then it will be justified if we retain our Premier League £70 Million pot of gold. As an example AVB recieved £11 Million compensation from Chelsea, then shortly after recieved another £4.5 Million from Spurs? so you can see why Huw Jenkins works the way he does. I've pulled the info below from Sporting inteligence site, which gives some insight on the cost and reasons:
This is the most extreme example of why firing and hiring with little apparent discernment is costly. But it is evident that the selection and appointment of the right manager is vital to a club’s short to medium term success, both on the pitch and financially. Players have a multitude of analysts from the disciplines of coaching, sports science, psychology and nutrition tracking their every move. So why not develop a form of analysis to gauge managerial performance? The research outlined in this article aims to achieve exactly that. A comprehensive literature review was undertaken to examine material relating to managerial dismissals and change within a sporting and business context.
Recent research showed that the average football manager in England lasts a little over two years in a job position. This is mirrored in professional US sport with head coaches averaging less than 2.5 years in their job. Managers are usually dismissed for either poor on-field performance, a breakdown in relations with club directors/owners, and / or increasing media pressure to deliver. In the modern game, spending power has become increasingly important for a club to be successful. However, there are contrasting views on whether sacking a football manager leads to improved team performance on average.
Of nine studies scrutinised from six countries, five of those nine – from England and Spain – stated that replacing a manager does improve a club’s on-field performance while four studies – from Belgium, the Netherlands, Italy and Germany – found that hiring a new manager did not improve team performance on average.
The results from England suggested that a club’s short-term performance increases when a new manager is appointed which may explain the rationale behind relegation-threatened sides changing their manager towards the end of the season.