Statistical guru Nate Silver, known previously for his work with baseball (PECOTA) and the 2008 election (fivethirtyeight.com) has unveiled a Soccer Power Index (SPI) for ESPN.  Rating international teams ahead of the 2010 World Cup, Silver’s goal is to “provide the best possible objective representation of a team’s current overall skill level.”

Essentially, the system calculates team performance, by weighting matches based on a competitiveness coefficient.  It also inputs as much international and club-based player data to provide accurate ratings and assess a country’s overall ability, trying to project future performance rather than merely rating the past. Full explanation here.

The SPI has weaknesses which are acknowledged.  International teams do not play many meaningful matches.  Soccer also doesn’t have many statistics, at least ones that are made readily available.  Those statistics it does have don’t necessarily indicate anything.

Michael Owen scores goals at a high rate making his numbers look awesome, but he does nothing else.  He doesn’t create space.  He forces his team to play in a way to facilitate him.  He may score more goals than Striker X, but Striker X may do more away from the ball to make the team better.  He’s earned fame and fortune.  He’s won the Ballon D’Or.  But, it’s worth noting Liverpool, Real Madrid, Newcastle and England all played better after he left.

As in most sports, soccer analysts unduly credit talent and individual agency over tactics.  The current German squad has one player playing outside Germany, Michael Ballack.  The French squad contains regulars at the top clubs in Europe (Barcelona, Real Madrid Arsenal, Manchester United, Chelsea).  Despite the talent disparity, Germany would be favored.

Lionel Messi and Steven Gerrard don’t undergo mysterious transformations when they put on the national team jerseys.  Their national teams just don’t play systems as complimentary to them as their club teams.

The ratings seem fair so far.  Few would seriously question the top five: Brazil, Spain, England, Netherlands and Argentina.  The one mild shock is that it promotes a few Non-European sides.  Chile, Uruguay and Ivory Coast are all in the Top 11, while Italy and Croatia are excluded.

Will it be as accurate as Silver’s election predictions?  Probably Not.  But it should improve on the asinine and irrelevant FIFA rankings.