What's Wrong With Dallas Cowboys Run Defense? Bills Loss Reignites San Francisco 49ers Fear

The Dallas Cowboys were embarrassed by the Buffalo Bills in Week 15, further distancing them from the NFC-best San Francisco 49ers.

The Dallas Cowboys kicked off in Western New York with a playoff berth cemented and their eyes on the top of the NFC. Instead, they fell flat, falling 31-10 to the Buffalo Bills and giving talk show hosts more ammo than the past two months combined.

Dallas’ unraveling came almost entirely from Buffalo running back James Cook. He continued his hot streak with a career day and an exclamation point, rushing for 179 of his 221 total yards and scoring two touchdowns. That would be more than enough to overcome the Cowboys’ pitiful offensive showing.

Buffalo Bills running back James Cook rushes for a gain against the Dallas Cowboys / Mark Konezny-USA TODAY Sports

Why did the Bills keep giving Cook the ball? 

"Why get away from it?'' said Buffalo coach Sean McDermott.

Sometimes, stinkers happen. But Week 15’s loss was a brutal reminder that temporarily clearing a hurdle in the NFC East means little when the NFC road - and we do mean "road'' when it comes to these Cowboys - runs through the San Francisco 49ers.

Concern after such an embarrassing loss would be mitigated if it was at the hands of some brutal injury luck or a big play botched by an official. Maybe Dak Prescott could have had an uncharacteristically off night that solely cost the team and promised to play better in the following week.

Instead, they gave up 266 rushing yards and looked like a team irredeemably thin at linebacker. Was this all about the injury absence of nose tackle Johnathan Hankins? It's got to be more than that.

Nobody wants to play a quarterback as good as Prescott in the playoffs, but San Francisco should be licking its chops at the opportunity to face this Dallas run defense.

Fans have seen the 49ers lean on the run before. It’s the engine of the offense that could win Brock Purdy an MVP. They ran for 113 yards when they eliminated the Cowboys from the playoffs last season. A year prior, they ran for 169.

San Francisco, featuring Christian McCaffrey, is a team that can – and will – happily run the ball, especially against elite pass rushes. Its run game is married to play action better than anyone else in football and has attacked vulnerable linebackers time and time again.

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On Sunday, the Cowboys’ linebackers didn’t look the part, their safeties struggled to tackle, and there was little in the trenches to provide optimism. Talks about home-road splits are necessary when they are as stark as Dallas’, but if teams can impose their will on the ground, it won’t matter where the Cowboys play.

Dallas is feeling the ill effects of its injuries and roster decisions that have left it last in the NFL in rushing success rate allowed. That’s a hard way to live in January.