Defenses win football tournaments, or so conventional wisdom holds. And that colloquialism is supported by overwhelming data. The winners of the last three World Cups and three European Championships conceded a combined two goals in 21 knockout round matches.
In some instances like the 2010 World Cup and Euro 2004, the winners scraped by their opponents with minimal offense, claiming the title after a series of 1-0 wins. In others, like Euro 2008 and 2012, there were a mixture of very convincing, multi-goal wins and close calls. But in every case, a tournament-winning team had to negotiate stubborn opponents at least once. In those fixtures, the importance of their strength in defense was paramount; a silly conceded goal could have spelled the end of their title aspirations.
Germany know all too well the importance of defense. They had arguably the best squad at Euro 2012, but a malfunctioning defense saw them knocked out in the semifinal by an Italy side whose worldliness was highlighted in their 4-0 loss in the final.
All tournament long, Germany's shakiness at the back was evident. Holger Badstuber and Jerome Boateng were dreadful, but Philipp Lahm and especially Mats Hummels helped the Mannschaft's defense do just enough to get by.
When Hummels made his first mistake of the tournament, which led to Italy's first goal in the semifinals, it put Germany against the wall. And despite all the attacking talent the DFB team possessed, the game changed drastically and Joachim Low's men were never able to recover.
Before the Italy match, the 25-year-old Hummels was perhaps the best player at Euro 2012. His performance was near-flawless on an individual level. And thus it was no surprise that Germany fell apart when he finally erred.
In spite of his mistake, the Dortmund defender is almost sure to be in Low's first XI at the 2014 World Cup. He is comfortably his country's most talented defender, and plays in a position where there is much less depth available than, for example, attacking midfield.
For better or for worse, Hummels is Germany's most critical figure heading into the 2014 World Cup. His brilliant man-marking has stifled the world's elite strikers into anonymity. But his mistakes have been crippling. Low will need him to be at his very best if Germany are to claim their first major international title since 1996.