>Incerteza, previsão e futebol, II

Simon Kuper and Stefan Szymanski, em Why England Lose, desenvolvem um algoritmo de computador que prevê resultados de jogos de futebol. Para essa copa, o algoritmo prevê a vitória do Brasil. Veja a ilustração da simulação abaixo, e a reação inglesa, à época do lançamento do livro, mais abaixo.

By SectionDesign, in Information is Beautiful.

Why England Lose by Simon Kuper and Stefan Szymanski
Two authors bravely attempt to explain England’s footballing failure and, like the team, ultimately lose, says David Runciman
The Observer, Sunday 9 August 2009
Michael Lewis’s Moneyball (2003) is one of those rare books that changed the way an entire industry operates. It told the story of Billy Beane, general manager of the Oakland Athletics baseball club, who turned a poorly resourced side into perennial winners by ditching the traditional tools of sports management – gut instinct, camaraderie, riding your luck – in favour of hardcore statistical analysis (known in baseball as sabermetrics).
steve mcclaren

Former England manager Steve McClaren speaks to the press after being sacked for failing for qualifying for Euro 2008. Photograph: Tom Jenkins

Once Lewis had explained how Oakland did it, their rivals started to follow suit and baseball teams began replacing gnarled old scouts with pointy-headed number-crunchers (which meant, among other things, that Moneyball cost Oakland its competitive advantage and the team is now back at the bottom of its league). Soon, other sports wanted in. The back offices of basketball, American football and ice hockey franchises are all filling up with maths graduates poring over spreadsheets of player performance looking for the secret of success.

At the same time, Moneyball changed the way publishers approached sports-writing. A good sports story needs plenty of human interest to sell and that has usually meant trying to see things from the players’ point of view. But Lewis revealed that the players often have no idea what they are doing and that sometimes only the numbers can tell the true story. Well before Freakonomics appeared on the scene, he showed how statistical analysis can provide all the human interest you need, just so long as you understand what the numbers are telling you.

Inevitably, these trends have crossed the Atlantic. For the past couple of years, the more progressive English football managers have been name-checking Moneyball and hinting at a statistical management revolution, though it’s not clear any of them has worked out what kind of statistics they are looking for. And now we have Why England Lose, a self-conscious attempt to write the Moneyball of football. If anyone can do it, it ought to be these two authors – Szymanski has recently published the best introduction to sports economics, Playbooks and Checkbooks, while Kuper is probably the smartest of the new generation of super-smart sportswriters. Unfortunately, their new book is a bit of a mess. It shows that doing a Moneyball is not as easy as it looks.

It doesn’t help that the weakest chapter is probably the first, in which the authors set out to answer the question that gives the book its title – why do England always lose at major tournaments? Given that it is one of the requirements of the genre that the numbers should tell us things we can’t see for ourselves, they have to pretend there is something utterly confounding about England’s failure. They quote tabloid expectations of England success before each World Cup as evidence that we go into every tournament expecting to win and are baffled when we don’t. But this is patronising as well as lazy; tabloid jingoism isn’t evidence of anything much except a desire to sell newspapers. Most England fans hope that England will win, but they hardly expect it, which is why it would be such a treat if it ever happened.

The real problem, though, is that Kuper and Szymanski can’t decide what it is they are trying to explain. On the one hand, they show that England’s record in all competitive matches, including qualifying tournaments, is actually slightly better than one might expect, given size and resources, meaning that on the whole England don’t lose. On the other hand, they argue that England’s record of failure at major tournaments can be put down to class and geography. English football remains a resolutely working-class sport, which means it is excluding middle-class talent, while England’s position on the fringes of Europe means we are not plugged in to the right networks for coaching and tactical innovation. So England are over-performing and underperforming at the same time.

But the truth is that England’s failure to win a World Cup since 1966 is really not that statistically significant. World Cups are eventually knock-out tournaments and knock-out competitions, especially since the introduction of penalty shoot-outs, depend a great deal on chance. Billy Beane never worried about Oakland’s failure to win the World Series (the knockout competition that rounds off the baseball season) because that was too often a matter of luck; it was only over the regular league season of 162 games that a small statistical advantage had the time to tell. Kuper and Szymanski admit as much (they even quote the relevant passage from Moneyball), so one finishes this chapter not with a sense that something curious has been explained by statistical analysis, but that the relevant statistical sample is simply too small to bear much explanation at all.

In their desire to ape an approach that was developed to analyse the highly distinctive sport of baseball, Kuper and Szymanski seem to lose sight of what is distinctive about football. They devote a chapter to explaining why the regular complaint that football has become too unequal (ie the rich clubs always win) is self-defeating, because inequality is part of football’s appeal. But though this is true, they miss the most obvious reason for it. Unlike baseball (indeed all other American sports), football is a low-scoring game that can end in a goalless draw. Every goal is an event, no matter how unequal the contest. Frankly, a Major League baseball game that ends 9-0 is a bit of a bore, but a Premier League game that finishes 9-0 lives on in the memory.

Equally, unlike baseball, football is not a sport that can easily be broken down into self-contained slices of action. It moves around the field in long, often chaotic sequences that, despite ProZone’s best efforts, are very hard to capture on statistical spreadsheets. The one part of the game that is clearly amenable to this sort of analysis is the penalty shoot-out and Kuper and Szymanski devote a chapter to it here. But it’s pretty elementary stuff and the conclusion – that the best penalty-takers don’t always shoot to their best side but randomise the sequence so as to keep the goalkeeper guessing – is hardly a tale of the unexpected. Serious sabermetrics really does look like rocket science in comparison.

There are still plenty of good things in this book. The best chapters are more conventional economics than freakonomics, explaining how and why money flows through the game, including an eye-popping account of how poorly the financial side of the sport is still managed by people with much more money than sense. There are also some fascinating stories, of which the most tantalising is a brief account of the rise of Olympique Lyonnais from relative obscurity to total dominance of French football, under their innovative owner, Jean-Michel Aulas. The success of Lyon and Aulas is probably the closest football has to the story of Oakland and Billy Beane, but Kuper and Szymanski are so keen to touch base with everything that they don’t give it the space it deserves.

It would also have been nice to hear more about the very few managers who seem to have found something in the numbers that everyone else is missing. The authors describe Arsène Wenger as one of the heroes of this book, but we learn almost nothing about him or his methods. No doubt access was a problem – managers such as Wenger are notoriously secretive. We also hear almost nothing about the most interesting man currently working in the football business, Jose Mourinho. Like Wenger, Mourinho has turned football management into a cross between an economics seminar and a personality cult. Neither man has won the Champions League with an English club, but then the Champions League becomes a knockout tournament in its later stages, so it doesn’t count. Instead, Mourinho is the possessor of one of the most remarkable statistical record in world sport – no team he has managed (Porto, Chelsea, Inter) has lost a league match at home since February 2002, a scarcely credible run of 117 matches. That is a truly curious football phenomenon that would be worth trying to explain, if only anyone could get close enough to find out how he does it. The Moneyball of football remains to be written.