Analysis of 88,000 matches shows soccer outcomes have become increasingly predictable

A pair of researchers at the University of Oxford has found that over the past few decades, the outcome of European League professional football (soccer in the U.S.) matches has become more predictable. In their paper published in the journal Royal Society Open Science, Victor Martins Maimone and Taha Yasseri, describe how they analyzed the outcome of 88,000 matches over the years 1993 to 2019 for multiple teams playing in professional football matches and what they found.

Over the past several years, some in the media have suggested that professional football matches are becoming less exciting because the outcome for many of them has become more predictable. Some have suggested that teams from wealthy countries or who are backed by wealthy entities have become better as they attract the best players with high play, while the skill levels of those less well off has leveled or fallen. The result, many fans have noted, is matches where everyone knows who will win before the match even starts. In this new effort, the researchers wondered if such suggestions were based on reality or if they were more the result of sour grapes. To find out, they studied football matches involving teams from Scotland, Greece, Turkey, Spain, Belgium and England’s Premier League over the years 1993 to 2019. Their analysis consisted of comparing scores of matches with predictions. The researchers then used what they had learned to build a model that could be used to predict the outcome of matches. They then ran the model on matches conducted over the study period and compared its results with the actual results of the matches.

In looking at their data, the researchers found that as the years unwound, their model’s predictions became better, which meant that the matches were becoming easier to predict. They also found that the model was quite accurate in general, correctly predicting the outcome of all matches with approximately 75% accuracy. They also noted that the model was able to correctly pick which team would win a match for some teams better than others, with inequality of resources as the biggest factor. Those teams that were well financed were more likely to win most of their matches. They also found that over time, home team advantage has waned to the point that it is no longer a factor in match outcomes.

Reference

Royal Society Open Science, Royalsocietypublishing