PageRank Algorithm and National Soccer Team’s Ranking
Source: https://www.technologyreview.com/s/535861/pagerank-algorithm-reveals-worlds-all-time-top-soccer-team/
The World Cup is one of the most popular sports events in the world. National soccer team players represent their country and compete for the FIFA World Cup Trophy. This article talks about how each national team’s ranking can be calculated by using the PageRank algorithm. Verica Lazova and Lasko Basnarkov at Cyril and Methodius University in Macedonia were the first to use this algorithm into finding the all-time ranking for national soccer teams. They collected data from over 7000 games between 210 countries in 20 previous World Cup tournaments since 1930 and used them to create nodes and links between teams that played with each other; in addition, they added weight to the algorithm depending on which team won over the others by how much and how many times. Using the PageRank system, they found that the result of the team rankings resembles closely to the rankings made by the official FIFA group. Their results showed that Brazil is the top-ranked team followed by Germany, Italy, Argentina, Spain, and England.
As Google’s PageRank algorithm was introduced in class as being used for ranking search results, it is interesting to see an example of such algorithm used in another context/setting like sports. We learned in class that PageRank ranks items based on the number and polarity of the links to nodes, where more important edges linked to a node suggests that the node is the more important. By applying the PageRank algorithm over multiple iterations, the normalized results determine a clear ranking of items, or in this case: national soccer teams. Brazil was no doubt the highest ranking team in the world as they played more games and stayed in the tournaments the longest (more edges), won the World Cup five times before and scored more goals against others (higher weight/importance). Some results, however, were not the same as FIFA’s official ranking, for example, Netherlands was ranked lower in FIFA than PageRank. One possibility could be that Netherlands just likes to score a lot of goals that pulled their ranking up in the PageRank algorithm as Lazova and Basnarkov assumed goals are a key component to the weighing. In conclusion, even though the weighing is relatively subjective, the PageRank system provides another way to determine team rankings in sports.