The board panics and fires the manger, it seemed the only remaining option. Granted, he did well last season – bought in some good players and promoted others, got them playing attractive football. But now the team needs defibrillation: a new manager with fresh ideas, inspiring players keen to prove themselves to him. A five game honeymoon period and, come spring, everything will be rosy again. After all, it worked so well for Sunderland last season.
This story seems to play out several times each season, but does it actually make any sense to fire a manager mid-season? A few years ago, Dutch economist Dr Bas ter Weel compared points-per-game won immediately before and after a manager has been fired in the Eredivisie. He demonstrated that, while there does tend to be an uptick in results in the following six or so games, it has nothing to do with the change in manager -- it's just mean reversion. Analogous to having rolled 6 ones in a row, the results were very likely to improve in the next 6 matches (or rolls) irrespective of whether the manager was fired or not.
In this blog I’m going to focus more on the longer term. Specifically, I’ll look at league rankings, comparing each team’s position at the end of the season against its position at the point when the manager was fired. In the harsh light of data, is there any evidence that clubs that sack their manager before April perform better over the remainder of the season than their closest competitors?
Mid-season sackings in the EPL and Championship
To answer this question, I identified every in-season manager change that has occurred in the EPL since the 1996/97 season, and in the Championship since 2006/07. Discarding outgoing caretaker managers (which I define as managers in position for four weeks or less) gave me a sample of 259 changes: 117 changes in the EPL and 142 in the Championship.
I then classified each manager departure into one of three categories: sacked, resigned, and mutual consent. For example, of the 117 in-season manager departures in the EPL over the last 20 seasons, 71 were fired, 36 resigned and 10 left by mutual consent. In this analysis we’re only interested in those that were forced out, which I will define as either sacked or leaving by mutual consent (the latter typically being a nice way of saying that he was sacked).
Managerial changes occur throughout the season, however I’m going to focus on those that occur in the middle portion of the season, from November through to March. Manager firings that occur early in the season can be due to reasons other than the team’s recent performance. Likewise, those that occur late in the season tend to be with an eye to the summer and following season. Retaining only the mid-season sackings left me with a final sample of 111, with just over half being at EPL clubs.
Finally, I also identified a sample of clubs that were in a similar league position to those that fired their manager (within 3 points on the date it was announced) but retained the same manager for the entire season. We’ll compare this baseline sample with the manager-change sample and see if the latter did any better.
Figure 1 plots the league position on the date the manager was removed (x-axis) against league position at the end of the season (y-axis), for each team in the manager-change sample. The black circles represent EPL clubs; the blue triangles Championship clubs. The red diagonal line indicates the same league position at departure and season end. The shaded regions above and below the line encompass teams that finished 3,6 or 9 places higher or lower than their position when the manager was sacked.
It’s clear that the majority of mid-season manager firings occur at clubs in the bottom half of the table. Of the EPL firings, 89% were at teams below 10th, and 66% were at teams in the bottom five places. Likewise, in the Championship 82% of sackings were at teams below 12th, and 51% at teams in the bottom 6. Of the 6 sackings that occurred at EPL teams in the top-half of the table, 4 were at Chelsea.
There is no evidence that teams gain any kind of advantage by sacking their manager. The median position change is zero, i.e. no change. Specifically: 30% of teams end in a lower position than when the manager was sacked, 23% see no change in their position and 48% see an improvement. If we compare this to the baseline sample -- clubs in similar positions in the table that retained the same manager for the entire season -- we find roughly the same proportions: 38% ended the season in a lower position, 17% saw no change in their position and 45% improved their position.
We can be more specific and look at clubs in the relegation zone when the manager departed. As the table below shows, of those that fired their manager 34% survived; of those that did not 39% survived. There is no evidence that firing the manager helps avoid relegation.
But what about Leicester?
Leicester fired Ranieri more than a month ago and have not lost since. They’re currently 2 places above their league position after his last game and seem likely to continue their recovery up the table. Didn’t they benefit from firing their manager?
While Figure 1 demonstrates that, on average, a club’s league position is not expected to improve after their manager is sacked, some individual clubs clearly did go on to significantly improve their league position. For instance, when Brendan Rodgers was fired from Reading in 2009/10 they were in 21st position; under his replacement, Brian McDermott, they went on to finish in 9th. Crystal Palace sacked Neil Warnock just after Christmas in 2014 when they were in 18th position; by the end of the season Alan Pardew had guided them to 10th.
On the other hand, clubs that do not switch manager also undergo miraculous recoveries. In the 2001/02 season Blackburn Rovers rose from 18th place in mid-March to 10th place by the end of the season. In late November 2008, Doncaster Rovers were rooted at the bottom of the Championship in 24th place; an eight match unbeaten run lifted them up to mid-table and they finished in a respectable 14th place. Both teams retained the same manager for the entire season: Graeme Souness and Sean O'Driscoll, respectively.
There are clearly circumstances that might necessitate a managerial firing in the middle of the season -- Leicester may be an example of this. But to pull the trigger without a clear diagnosis of what has gone wrong is a sign of desperation and poor decision-making. Indeed, over the last twenty seasons, EPL managers appointed during the summer months have, on average, lasted over 100 days longer in their jobs than those appointed during the season. Coupled with the large compensation payments that are often necessary to remove a manager, mid-season changes may actually end up harming the long-term prospects of a club.
 Specifically: Gullit in 97/98, Scolari in 08/09, Villas-Boas in 11/12 and Di Matteo in 12/13.