## Connecting network theory with futbol

http://www.technologyreview.com/view/428399/pagerank-algorithm-reveals-soccer-teams/

The year 2012 was a great year for soccer lovers, as millions of people worldwide gathered to witness the dominance of Spain in the Euro 2012 soccer championship. After defeating Italy 4-0 (a rather rare and one-sided result), Spain has successfully won three major titles in a row (Euro 2008, World Cup 2010, and Euro 2012) and established  the  team as one of the best teams in history.

Spain’s massive success was thought to be the direct result of Tiki Taka, its possession-oriented style of play (as demonstrated here by the Spanish club Barcelona F.C.: http://www.youtube.com/watch?v=lGuaQ1khn2k). To analyze Spain’s style, Javier Lopez Pena at University College London and Hugo Touchette at Queen Mary University of London have developed a way to visualize the Beautiful Game:

“Their idea is to think of each player as a node in a network and each pass as an edge that connects nodes. They then distribute the nodes in a way that reflects the playing position of each player on the pitch. “

Interestingly, although this seems to be an extremely simple approach, the resulted networks have revealed many reasons why Spain was more effective as a team/network. For instance, in the picture above which compares Spain with Netherlands (the final of the 2010 World Cup),   Spain is obviously more connected as a component, which means that the ball is distributed evenly among the teammates and it is very hard for the opponent to obtain possession, since Spain is playing as one (instead of simply 11 individuals). In addition, one can also observe the formation of many strong triadic closures in the midfield area, which points to Spain’s deadliest weapon: their midfielders who can control the ball and trust each other comfortably. Along with other superior properties mentioned in the article, such as closeness centrality (“how easy it is to reach a given node in the network”) and  betweenness centrality (“the extent to which a node lies on a path to other nodes”), one can easily see why Spain is quantitatively better than any other team in the world at the moment: As a highly connected network, Spain is able to keep the ball to themselves without relying heavily on any individual player, and as a result, create countless scoring opportunities and frustrate its opponents throughout the game.

Personally, I am a big fan of Manchester United and am fond of the English playing style, which emphasizes on pure power and speed (as demonstrated here: http://www.youtube.com/watch?v=yoUaAvbfVlg). However, one must admit that the style of Tiki Taka is scientifically more efficient (although it may or may not be the most exciting player style, as it is subject to individual’s preference), and thus was able to put Spain into its golden era in the world of futbol.

– JeffWhy