Social net working: football ratings 2.0

Rating player performance in football (soccer for you Phillistines) games has always been a fairly arbitrary affair. It’s difficult, unless you’re going to count every pass, tackle and off the ball run, to get a fair measure on the contribution of players not directly involved in putting the ball into the back of the net – and what about all those build ups where a striker fails at the last hurdle?

Now, Luís Amaral, a “complex-systems engineer” at Northwestern University in Illinois, has applied social networking styled analysis to the interactions between players that lead up to shots on goal.

An avid soccer fan, Amaral wanted to measure team and player performance in a way that takes into account the complex interactions within the team and each player’s contribution. So he turned to an unlikely source: social networks. Applying the kinds of mathematical techniques used to map Facebook friends and other networks, Amaral and colleagues created software that can trace the ball’s flow from player to player. As the program follows the ball, it assigns points for precise passing and for passes that ultimately lead to a shot at the goal. Whether the shot succeeds doesn’t matter. “There’s lots of luck involved in actually getting it in,” Amaral explains. Only the ball’s flow toward the goal and each player’s role in getting it there factors into the program’s point system, which then calculates a skill index for each team and player.

The results:

When the researchers used the program to analyze data from the 2008 UEFA European Football Championship, the indices closely matched the tournament’s outcome and the overall consensus of sports reporters, coaches, and other experts who weighed in on the performances.

Cool. More info here.