English clubs: statistically sound or struggling to score?
© AP/Martyn Hayhow
It’s official: English football teams score fewer goals.
Soccer teams worldwide are scoring more goals than they ought to be, whereas English teams seem to follow statistical expectations. The news may delight fans outside England, but it is puzzling the physicists who have found that the chance of a high-scoring game is significantly greater than it may first appear1.
John Greenhough and colleagues at Warwick University in Coventry, England, analysed the scores of over 135,000 football (soccer) games in the domestic leagues of 169 countries, played between and 1999 and 2001.
In such a random process, bigger scores become increasingly unlikely. There are more 1-1 draws or 2-0 victories than there are 6-1 victories, for example. According to the rules of statistics, the chance of a high score should become less and less likely, the higher the scores become - something called a Poisson distribution.
But physicists have known for several decades that football games are far from normal. The chance of goal scoring doesn’t stay even throughout a match, but depends on the previous number of near-goals. The Poisson distribution can be modified to allow for this, resulting in a ’negative binomial probability distribution’.
In a further analysis Greenhough and colleagues find that for English league and championship matches for the seasons 1970-1971 and 2000-2001 the total scores of all matches fit a negative binomial distribution well. In contrast, domestic matches worldwide produce many more ’extreme events’ (high scores) than predicted by this statistical distribution.
Why the difference? Does it mean that the English defence or goalkeepers are unusually good, or the strikers are unusually poor? Possibly, but there may be a statistical explanation: in terms of probability, football games may behave more like the stock market or earthquakes.
In recent years, statistical physicists have realized that probabilistic processes underlying these complex phenomena show something called strong correlations.
Correlations arise when the behaviour of one part of a system is strongly influenced by the behaviour of other parts. In football, this suggests that goals become increasingly likely as their number mounts up. Fans and players will already have an intuitive notion of the effect. When trailing by 5-0, say, a defence is more likely to ’crack’ than when the score is 2-0. Even if the teams are well matched, the game becomes more ’volatile’ if it reaches, say, 4-4: goals then begin to flow more readily.
Why English teams don’t show this effect so strongly is a question sure to provoke endless debate among armchair strategists.
PHILIP BALL | © Nature News Service
The Internet of Things: TU Graz researchers increase the dependability of smart systems
18.02.2019 | Technische Universität Graz
Stanford researchers create a wireless, battery-free, biodegradable blood flow sensor
09.01.2019 | Stanford University
New research group at the University of Jena combines theory and experiment to demonstrate for the first time certain physical processes in a quantum vacuum
For most people, a vacuum is an empty space. Quantum physics, on the other hand, assumes that even in this lowest-energy state, particles and antiparticles...
Physicists in the EPic Lab at University of Sussex make crucial development in global race to develop a portable atomic clock
Scientists in the Emergent Photonics Lab (EPic Lab) at the University of Sussex have made a breakthrough to a crucial element of an atomic clock - devices...
Every year earthquakes worldwide claim hundreds or even thousands of lives. Forewarning allows people to head for safety and a matter of seconds could spell...
Scientists of the Department of Physics at the University of Hamburg, Germany, detected the magnetic states of atoms on a surface using only heat. The...
Combining an atomically thin graphene and a boron nitride layer at a slightly rotated angle changes their electrical properties. Physicists at the University of Basel have now shown for the first time the combination with a third layer can result in new material properties also in a three-layer sandwich of carbon and boron nitride. This significantly increases the number of potential synthetic materials, report the researchers in the scientific journal Nano Letters.
Last year, researchers in the US caused a big stir when they showed that rotating two stacked graphene layers by a “magical” angle of 1.1 degrees turns...
11.03.2019 | Event News
01.03.2019 | Event News
28.02.2019 | Event News
18.03.2019 | Power and Electrical Engineering
18.03.2019 | Materials Sciences
18.03.2019 | Physics and Astronomy