Marco Silva was praised too quickly then sacked too soon

When a football manager is sacked I think of David Hume and Pierre-Simon Laplace. They lived before there was football. Hume was born in 1711 and Laplace died in 1827. Hume was a philosopher, Laplace a scientist. Each in a different way pondered the causes of effects, and the difficulty of establishing them.

And that is where we make mistakes not only when evaluating the performance of football managers but also when evaluating the performance of football teams. Our mistakes can cost us money if we are football club owners or football bettors.

We make mistakes by assuming that if this happened after that happened then this must have happened because that happened.

Take as an example Watford’s sacking of Marco Silva.

Watford got Silva last summer. They started this season with four wins, three draws and one loss in their first eight Premier League games. Those results were surprisingly good.

Shortly afterwards Everton sacked their manager and tried to sign Silva. Watford, in effect, said Silva was too good a manager for them to let him leave. Two months later, in effect, they said he had become too bad a manager for them to let him stay.

They said Silva had been distracted by Everton’s bid and his work had suffered. They might have been right. But in such circumstances nearly everything that everyone says is wrong.

Watford started the season unexpectedly well. People said: “Hey, what has changed? Watford have a new manager. He must have made the difference.”

Everything happens for a reason, people say. They are right. They are wrong only in thinking that when something happens they can identify the reason. For many effects there is more than one possible cause. And as Hume realised after scratching his head until it hurt, there is no way of proving which one it is.

B might happen after A but that does not mean B happened because of A. Outside my bedroom window early in the morning birds sing. Then the sun rises. Do the birds think their song makes the sun rise?

Watford lost only one of their first eight Premier League games. Of the next 16 they won three, drew two and lost 11. Those results were surprisingly bad. Watford’s owners were not the only ones to conclude that Everton’s approach had got into Silva’s head.

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Old managers who look back honestly over a long career will usually admit that there were times when things went well or badly but they did not know why. Things can happen for reasons that are too complicated for us to work out. An effect can have many causes, mixed in an elaborate combination. We will not know which ones they are or what it is.

I am not saying that we can never form any understanding of anything. What I am saying is that our conclusions should be hazier than they are. If they were less specific, paradoxically, they nearly always would be more accurate.

Watford replaced Silva with Javi Gracia. Someone who writes about Spanish football said Gracia was in demand and you could tell why if you looked at what has happened to Malaga since Gracia left. Last season they dropped below mid-table and this season they are bottom. I shook my head and sighed. It sounded like another oversimplified diagnosis of cause and effect.

So I looked at Malaga’s results – not those after Gracia had left but those before he had arrived. Gracia managed Malaga for two seasons, during which they averaged 49 points. Over the six previous seasons Malaga had averaged 50 points. Malaga’s results with Gracia were the average of their results with his five predecessors.

Malaga’s decline since Gracia left probably has little if anything to do with any difference between him and his four successors.

There is a branch of mathematics called Bayesian inference. It is named after an 18th century clergyman called Thomas Bayes. It should have been named after Laplace. What is called Bayes’s theorem should be called Laplace’s theorem.

Bayes wrote a paper that Laplace read. But neither the theorem nor the sums behind it come from Bayes. They come from Laplace. It is yet another illustration – a particularly apt illustration – of how the origin of things can be confusing.

Results are a funny business

Often when a club sack their manager they say football is a results business. This is funny because they do not act as though it is.

Michael Mauboussin, head of global financial strategies at Credit Suisse, wrote a book called The Success Equation. Its subtitle is Untangling Skill and Luck in Business, Sports, and Investing.

Mauboussin said that in sport and in investment you do not always get what you deserve. There can be a mismatch – sometimes a huge mismatch – between input and output.

Someone can make bad decisions but get good results. Someone else can make good decisions and get bad results. Owners would not be acting in the best interests of the business if they sacked everyone who had bad results and gave a pay rise to everyone who had good results.

Instead they should identify what each employee had done and then ask themselves whether there were reasonable grounds at the time to think that input would produce a good output. This is not easy. But it should be done. It is fairer and likely to be better for the future of the business.

Paradoxically the owners of results-based businesses should not judge their employees on results.

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