Sprow: Defense will define Dallas

The Dallas Cowboys last went to the playoffs in 2009. That 2009 season wasn't the last time we've seen a steady run of peak by quarterback Tony Romo. No, it was the last time Dallas has fielded an above-average defense. That 2009 defense finished second in the NFL in points per game allowed (15.6), seventh in weighted defensive efficiency and was fourth overall against the run.

If the 2013 Cowboys are going to return to the playoffs, it won't just be because Romo reaches a new peak, it will be because the defense finally comes back to a form worthy of a playoff team. The good news is they have the talent do so. The bad news is they face three critical questions in their attempt to make that happen.

In this Insider story, ESPN's Chris Sprow explainsInsider why defense, not Tony Romo, will define Dallas this season.