How important is winning your group?
At the World Cup, group winners are better than group runners-up. An advanced statistics degree or thorough knowledge of soccer isn't necessary to figure that out.
Yet every tournament inevitably raises questions about how important it is for a team to win its group after locking up a knockout-stage berth before its final match. Some analysts advocate resting players or allowing youngsters to gain experience. Others encourage strategic maneuvering to obtain specific matchups in the round of 16.
A simple look at recent history reveals what is expected: Group winners fare better in the knockout stage than runners-up.
The 1998 World Cup was the first tournament played under the current eight-group format in which the top two finishers advance to the knockout stage. The group winners are then paired against the runners-up to form the eight round-of-16 matchups.
In the past three World Cups, the first-place finishers won twice as many round-of-16 matches as the runners-up. Three times as many winners reached the semifinals, and five of the six finalists won their groups.
As for the 2010 champion, the ultimate victor likely will be one of the eight group winners. Each of the past six World Cup champions won its group. Since the group stage was introduced in 1950, 11 of the 15 champs have won their groups. The last group runner-up to win the World Cup was Italy in 1982.
Determining how much of this disparity is due to the quality of the group winner and how much is due to the inferiority of the runner-up is impossible. But the combination of playing well and playing an opponent that hasn't played quite as well undeniably indicates that a country would much rather win its group.
This is a fairly intuitive point. Teams that earn more points in the group stage are generally better teams and get to face teams that are playing a notch worse. In this case, recent history supports conventional wisdom, which should put to rest any notion that a team ought to ease up in its final group match.
Paul Carr is a researcher for the ESPN Stats & Information group.