The Cowboys defense is dominant, but is it enough to win a championship?

Cooper Rush is 4-0 as the Cowboys' quarterback in place of the injured Dak Prescott, but a dominant defense has been the biggest reason why. Since Prescott went down, Dallas has allowed an average of 13.3 points per game, second to only the 49ers in the NFC over that span. 

Dan Quinn's unit has come up huge, but is it dominant enough for the Cowboys to win a championship without more help from the offense?

The answer to that question might not be in the defense, but instead in the offense. The Rams finished near the middle of the pack in total defense last season and won the Super Bowl anyway. Through five games, the Cowboys are 24th in points per game and 27th in total yards per game. The running game has done a nice job with Prescott out, but it still only comes out to 15th in yards per game. 

The last six Super Bowl champions have finished ninth, seventh, sixth, fifth, seventh and fourth in total offensive yards, respectively. Twenty-seventh isn't good enough for the Cowboys to make that kind of run, and it's so far off from the top 10 that it's hard to believe Dak Prescott's return can make such a massive difference. 

Dallas' offense struggled in Week 1 even with Prescott under center, and offensive line issues could be a roadblock to achieving last season's offensive success.

If the Cowboys want to seek inspiration from another defense-first champion, they'll have to go back to the 2015 Broncos. The Broncos finished 16th in total offensive yards but allowed the fewest yards per game of any team and rode a historically good defense to a Super Bowl win. 

As good as Dallas' defense has been, it's not quite at that level yet, sitting seventh in yards allowed per game. While the Cowboys have a ferocious pass rush similar to the 2015 Broncos, they might not have the secondary to match them.

The road to a defense-first championship is daunting. If the Cowboys are going to do it, it's going to take improvement all-around.