The ‘managerial bounce’ is a myth: this phantom bounce is nothing more than regression to the mean

Getting rid of managers mid season can work – but not for the reasons people think. Some teams who get rid of managers do benefit from a short-term improvement in their results. But this has nothing to do with the new man in charge.

Managers are not only sacked when their teams are at a low ebb. They also tend to be sacked when their teams are being very unlucky. Looking at analysis of points earned by teams in the big five European leagues in the eight games before and after sacking a manager, In the eight games before a manager leaves, the team averages 0.8 points per game. In the eight subsequent matches, they average 1.2 points per game – an improvement. But based on expected goals – the quality and quantity of chances created and conceded – the team actually ‘deserved’ 1.2 points per game in the eight points before the manager left, exactly the same as they actually got under their new boss.

So what really changes with the new manager?

Well it isn’t the new tactics or motivational team talks. It’s simply that they don’t suffer from the old manager’s bad luck.

Except, if a struggling manager is persisted with, the team’s luck improves anyway – and their results improve by as much as if they had been sacked. That’s why, on average, Premier League sackings make no difference at all to a team’s performance.

Looking at Premier League sackings from 2000-2015, comparing underperforming teams who sacked their managers after a terrible run to those clubs who kept their managers after the same dire form, results improve, and by the same amount, regardless of whether or not the manager is sacked. Analysis of other leagues have shown the same.

The ‘managerial bounce’ is a myth: this phantom bounce is nothing more than regression to the mean. On average, an in-season replacement of the manager has zero effect on performances, either during the season or in the long run.

Its not to say that managers can’t make a difference at all. It’s just that you have to be a very good (or bad) manager to do so, and the vast majority of managers are bunched in the middle, where replacing one with another will statistically have no more impact than fans starting to go to games in a pair of lucky socks.

In English football from 1973 to 2010 only 10 per cent of top-flight managers consistently overachieved when wages were taken into account, and panic-stricken teams who sack their managers after a dodgy period in mid-season hardly have their pick of that top 10%. Instead, unless they are prepared to spend a lot poaching another club’s manager – and most teams either aren’t, or don’t have the means to – they are left looking at a pool of unemployed managers.

Most are unemployed for a very good reason. In English football, clubs who have just sacked a manager tend to replace them with a “lower ranked, experienced” replacement. In a quarter of cases, the new manager actually has a lower estimated ability than their predecessor. So much of a managerial merry go round is is change for change’s sake, without clubs giving any proper regard to whether the new boss will genuinely be any better than the old boss.

Why does the never-ending cycle continue? The reasons go beyond football.

90 per cent of drivers believe they are above average: people are not very good at realistic self-assessment. This goes for football also: owners and fans are often incapable of seeing where their team actually stands, rather than where they would like it to. The truth is that there is a 90 per cent correlation between teams’ wages and their results.

Clubs also misinterpret randomness. Because football is a low-scoring game, a lot of results hinge more on chance than other sports. Who wins a football game is determined by 50 per cent skill and 50 per cent luck, largely because about half of all goals occur after a moment of fortune – ball deflections, lucky bounces, bad decisions from a referees, or even the impact of a stray balloon on the pitch. And the football season also has comparatively few games – each Premier League teams plays under half as many league games as NBA teams and under a quarter as many as MLB teams – so judgements are made on a smaller sample size. Add in the financial consequences of relegation from the Premier League, and you have an attitude towards short-termism.

None of this is suggesting that all managers bullet-proof. Some sackings are justified. West Ham, for instance, 18th on expected goals models this year, after an underwhelming 2016/17 season, suggesting Slaven Bilic was rightly removed.

Yet the point remains that the median length of an English football manager is only a year. Most of these sackings are undeserved (they are overrated solutions).

Rather than be seduced by the myth of constantly changing their manager, clubs who spend so much cash on sackings would be better off instead investing in areas – scouting, youth coaching or improving facilities – where it could actually make a difference.

Garry Monks team were criticised heavily for not taking their chances and Tony Pulis has to work with the same group of players, so far we are seeing the same pattern, which is not the fault of the new manager, it is that basic regression to the mean.
Middlesbrough now need to stick with Tony Pulis, believe in his template and look to next season for him to build a promotion winning squad.


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