It is a long held belief, among owners and fans, that sacking the manager will have an impact on playing performance. It seems in no other walk of life is the manager held so responsible for the results of his underlings. There are a couple of factors that make measuring the rights and wrongs of this decision difficult.
- What effect does any manager have on the team?
- How do you predict what would have happened if you hadn’t sacked the manager?
What effect does any manager have on the team?
Although I couldn’t find any studies about English Football there are studies done on Baseball and Basketball. A recent paper written by J.C. Bradbury. In “Hired to be Fired: The Publicity Value of Free Agents”, Bradbury looks at how a baseball’s players performance is impacted by a change in managers. – It doesn’t.
Another study looked at 62 NBA coaches across thirty years of data. Across this sample, only 14 coaches were found to have a statistically significant and positive impact on player performance. So most NBA coaches – like most baseball managers — do not appear to make their players more productive.
Do football (soccer) managers make much of an impact? I suppose that is still and may always remain an unanswered question.
How do you predict what would have happened if you hadn’t sacked the manager?
Luckily for us there is a study that has looked at this. I recently came across a fantastic piece of research examining results and sackings in English Football from 1972 to 1993. ‘Team performance and managerial change in the English Football League’ by Richard Audas, Stephen Dobson and John Goddard (link). They examined 42,624 match results and 821 managerial spells. The main problem to avoid is ‘a selection problem’. Let’s take tossing a coin to explain this a little more. Let’s decide that Heads = Won and Tails = Loss. If we decide that we will toss a coin 30 times – at any stage in that process 4 tails in a row might occur. If we changed the coin tosser at that stage and suddenly there is a run of heads would we think the guy flicking the coin was the reason?
The same situation has to be avoided when examining a managers performance. See table 1 for the results found in this study.
Average Win Ratio
|6 matches before||6 matches after||12 matches before||12 matches after||18 matches before||18 matches after|
|Teams which terminated||0.37||0.44||0.40||0.45||0.42||0.46|
|Teams which did not terminate at comparison point||0.37||0.48||0.40||0.48||0.42||0.49|
The upper panel of table 1 reports the average win ratios for selected numbers of matches (6, 12 and 18) preceding and following each termination of a spell. At first sight these figures appear to substantiate the view that termination creates a short-term improvement in performance, because no matter whether the comparison is done over 6, 12 or 18 matches before and after termination the post termination results demonstrate a clear improvement over those preceding termination.
Do these figures constitute convincing evidence that managerial termination has a favorable short-term impact on team performance? The authors believe not. The results are shown in the lower panel of table 1. Here, we find that the average improvement recorded by the teams which did not terminate after the point of comparison is in fact greater than that recorded by the teams which did terminate, no matter whether the comparisons are made over 6, 12 or 18 matches before and after.
So it seems if you can get past the first hurdle – that managers do in fact make a difference!, you are faced with some grim facts about how sacking your manager will turn your season around. Something for all owners and fans to ponder.