Building upon my previous post, the table above shows the residuals for each team after their first match (except South Africa and Uruguay, who played their second match today) in the 2010 World Cup. A residual is the difference between an observation (goal differential in the first match) and the predicted value of the model (predicted goal differential of the first match according to the Soccernomics model). Residuals are useful in:
- Determining which observations are over- or under-performing versus the model
- Determining whether the model (regression equation) satisfies the statistical tests required of it
I will continue to use the residual approach to quantify how each team is doing against their corresponding Soccernomics predicted performance as both the second and third matches are completed for all teams. At the end of group play, I will be able to comment as to which teams were the biggest over- and underachievers in the tournament, as well as comment as to whether or not the Soccernomics model actually applied well to the tournament.
Before getting to that point, however, we can gain some useful observations from each team's first match. Germany's top position in the list, given a 4-0 drubbing of Australia, is not a surprise. As I have said in previous posts, Slovenia can easily play this tournament's "giant killer" role if they keep up their great start and tie or beat the US and England. Finally, even though the Dutch and Danes only had a 0.2 predicted goal differential, Holland's 2-0 win moved them to the third spot in the ranking.
At this point, as only one game has been played, the list is basically a reflection of who won and lost. The bottom three teams are the teams who lost to the top three - the bottom half is an inverse of the top half. As group play goes on, this list will get more jumbled and I will provide commentary as to the bottom three teams.
Finally, how about the Swiss upset of Spain today? Spain, favored by nearly a full goal in the Soccernomics model, finds itself in the bottom of the rankings around Algeria, Serbia, and South Africa. They will be playing catch up to Chile and Switzerland the rest of the way, hoping one of them stumbles in their next two matches. Perhaps there is hope for the rest of the world against the Spanish juggernaut that the press wants to prematurely crown champions.