Bitter NFC East rivals meet in an important early-season clash when the Washington Redskins host the Dallas Cowboys on Sunday. The Cowboys came out on fire, rolling the New York Giants 35-17 in the season-opener, while the Redskins finished flat in theirs, blowing a 17-0 lead in a 32-27 loss at Philadelphia. Kickoff from FedEx Field is set for 1 p.m. ET. Dallas has won seven of the last nine games in the series and is 5-1 in the last six games played at Washington. Accordingly, Jerry Jones' squad is a 5.5-point favorite in the current Cowboys vs. Redskins odds. The over-under, or total number of points Vegas thinks will be scored, is 46.5. Before you make any Cowboys vs. Redskins picks or NFL predictions for Week 2, see what famed pro football expert Mike Tierney has to say.

An acclaimed sportswriter whose work appears in the New York Times and Los Angeles Times, Tierney has reported from seven Super Bowls. Now a SportsLine expert, Tierney was all over the Patriots, enabling him to finish the season with a sparkling 63-46 record against the spread. Over the past three seasons, he is 197-162 in the NFL, returning over $1,800 to $100 players. Anyone who has followed him is way, way up. 

Now, with the regular season in its second week, Tierney has evaluated Cowboys vs. Redskins from every angle and locked in a strong pointspread pick. He's only sharing it over at SportsLine. 

Tierney knows the Cowboys want to assert their dominance in the NFC East, especially with one divisional win under their belts already. Quarterback Dak Prescott completed 25-of-32 passes for 405 yards and four touchdowns against the Giants a week ago. In six career starts against Washington, he has thrown for 1,294 yards and six scores. 

Running back Ezekiel Elliott shook off some rust as he returned from a preseason holdout and responded with 53 yards and one touchdown on 13 carries. He is only going to get stronger as the season progresses and he returns to game form. In 41 career games, he has rushed for 4,101 yards and 29 touchdowns. He's also caught 136 passes for 1,209 yards and six more scores. 

But just because Dallas has plenty of firepower doesn't mean it'll cover the Cowboys vs. Redskins spread. 

Tierney knows that despite the loss, the Redskins have plenty of weapons. One of those is quarterback Case Keenum, who was sharp in his Washington debut, completing 30-of-44 passes for 380 yards and three touchdowns. He had a quarterback rating of 117.6.

Helping spark Washington's offense in the opener were wide receiver Terry McLaurin and running back Chris Thompson. McLaurin, the Redskins' third-round draft pick, had a successful debut with five receptions for 125 yards, including a 69-yard touchdown. Thompson, a six-year veteran, added seven receptions for 68 yards. With running back Derrius Guice sidelined with a knee injury, the team will turn to veteran Adrian Peterson, who rushed for over 1,000 yards last season.

We can tell you Tierney is leaning under, but he's isolated a critical X-factor that has him going big on one side of the spread. He's only sharing what it is, and who to back, at SportsLine. 

Who wins Redskins vs. Cowboys? And which critical X-factor makes one side of the spread hit hard? Visit SportsLine now to see which side of the Redskins vs. Cowboys spread to back on Sunday, all from the acclaimed expert who went 63-46 on NFL against the spread picks last season, and find out.