Pagerank vs FIFA rankings
We have learned that Pagerank is a tool used by websites to rank their importance, which is dependent upon the links it has from other important sites. These links, or endorsements, are from hubs to authorities, with hub scores determining the quality of links as a list, and authority scores conveying the level of endorsement of a page. The algorithm is an iteration of counting links to a page and the importance of those links from the pages they point to. This article in MIT Tech Review explores the different uses of Pagerank, outside of websites. Some include ranking scientific papers from the references they contain, or elections where “everyone is a candidate and can vote for anybody else.”
Perhaps most interesting, Lazova and Basnarkov from Methodius University created an all-time ranking of the world’s national soccer teams using Pagerank and outcomes from the 20 World Cup tournaments since 1930. These researchers assumed that “a team should be ranked highly if they have beaten other highly ranked teams.” The network created had teams—from 210 countries—as nodes and links between them if they had played against each other. The hub and authority scores were determined by the results of which team won against the other and so on.
After a number of iterations of the Pagerank algorithm, the top ranked team was Brazil, followed by Italy then Germany. Brazil had won the tournament more than any other nation, played the most games, and scored the most goals, so being first made sense. Fifa had ranked Brazil first followed by Germany then Italy. However, when comparing their Pagerank list to Fifa’s (the international football association) all-time list there were still some differences. Netherland was 8 on Fifa and 4 on Pagerank. Czechoslovakia was 9 on Pagerank’s list, but doesn’t exist at all on Fifa’s, as its country status was dissolved in 1993. The current Fifa ranking is essentially determined a 12 month average and previous 36 month average, and takes into account the importance of a match and the strength of opponents. It’s intriguing to see the similarities and differences between rankings from Pagerank and Fifa’s own system, and the two probably would have been more similar if the researchers took into account the time of the matches. While Pagerank does not take into account the age or status of a page or link, it is still usually accounted for as the bow-tie structure of the web makes it hard for outdated pages to be strongly endorsed.