Since the 31st Premier League campaign ended on 31 May, three managers have signed up for the merry-go-round of running a Premier League team.

With Ange Postecoglu, Andoni Iraola and Mauricio Pochettino taking on a new challenge, the number of clubs hiring managers since the start of last season stands at a mind-boggling 11 out of 20.

Looking at the trend over the past few decades, you can be confident, the flow of managerial casualties will continue this season as teams fight for the ever-increasing financial rewards on offer.

BBC Sport takes a look at how increasingly insecure a manager's job is, when most sackings happen and whether pulling the trigger actually has the desired effect.

A total of 41 Premier League managers last season

The 55% of Premier League teams making a change last season is the largest percentage of the 'big five' European leagues. France and Spain were close behind with 50%, Germany was at 44% and Italy 35%.

These numbers follow a trend across the continent where some leagues had more than 90% of teams change their manager during 2022-23, according to the CIES Football Laboratory in Switzerland.

The impatience of owners has been growing: the number of teams making a change is almost double what it was in the 1980s.

In fact, 40 years ago only five teams made a change. Even the first year of the Premier League in 1992-93 featured only four changes, and this was when the division consisted of 22 teams.

The average number of changes per season during the 1980s was 6.5 (30%). During the past decade that figure is 8.3 out of 20 teams (42%), with highs of 55% last season and in 2021-22.

While changing a manager during the summer can be understandable, making a switch mid-season usually means something is going wrong. This trend has also been growing.

Over the past decade 83 Premier League managerial changes have taken place during the season. Not surprisingly, most of the changes come around the middle of the season. Few owners are trigger-happy in the first two months and by April and May it's usually too late.

The latest in-season sacking, by date, was Nigel Pearson being sacked by Watford in July 2020 (after the Covid-19 restart). He had two games left to play, while Roberto Martinez departed Everton with a single game left in May 2016.

Last season wasn't just noteworthy because of the number of clubs making a change. There was an unusually high number of clubs making multiple changes and even more installing interim managers.

In all a total of 41 managers were in place at some point, and some held positions at more than one club.

The top half of the table had an average of 1.4 managers, the bottom half an average of 2.4. Stability can be important, as Nottingham Forest proved when keeping faith with Steve Cooper, while all three relegated teams made changes to no avail. Leeds United and Leicester City were still making changes in April and May.

How well (or otherwise) did teams do after making a change?

As can be seen from the table, it's a coin flip as to whether a change will be beneficial.

Aston Villa, Bournemouth, Everton and Crystal Palace can feel vindicated, while Chelsea, Tottenham, Leeds and Brighton (while it wasn't their choice) all did worse. For Southampton and Leicester, it made virtually no difference and their downward spiral was too far gone to be averted.

Manchester City and Liverpool have been two of the best Premier League teams of recent years and they have the longest-serving managers.

Arsenal have one of the next longest. Will their upward trajectory continue next season? Will the promoted teams keep faith with their managers when things get tough?

These and many more questions will be addressed as the season unwinds, but what is very likely is that half of the managers on the opening day will not be in the job by the time the season is over.