One of the NFL's storied rivalries will be renewed when the San Francisco 49ers and Dallas Cowboys collide in a Divisional Round playoff game on Sunday. It will be the ninth playoff matchup between the teams, with the Cowboys holding a 5-3 edge. This season, San Francisco (14-4) and Dallas (13-5) meet again with a spot in the NFC Championship Game on the line. 

Kickoff is 6:30 p.m. ET. San Francisco is a four-point favorite in the latest 49ers vs. Cowboys odds from Caesars Sportsbook while the over/under for total points scored is 47.

Before you make any Cowboys vs. 49ers picks or NFL Divisional Round predictions, you need to see what SportsLine senior analyst Larry Hartstein has to say. 

A former lead writer for Covers and The Linemakers, Hartstein combines a vast network of Vegas sources with an analytical approach he honed while working for Pro Football Focus. He entered the 2022 NFL season 427-344 all-time on NFL side picks (plus $3,764 for $100 players), including 394-330 against the spread. Hartstein went 68-50 ATS and 8-3 on money-line plays last season for a profit of $1,552.

Hartstein also is 14-4 on his last 18 against-the-spread picks involving the Cowboys, meaning he's uniquely qualified to make this pick.

Hartstein knows that San Francisco has arguably the best defense in the NFL. The 49ers led the league in both scoring defense (16.3 points per game) and total defense (300.6 yards per game). They also tied for the NFL lead in interceptions (20) and tied for second in takeaways (30).

Hartstein also knows that Cowboys quarterback Dak Prescott is coming off one of the best performances of his career. In the 31-14 Wild Card win over the Buccaneers, Prescott completed 25-of-33 passes for 305 yards and four touchdowns. He also ran for another score, becoming just the fifth player in NFL history with at least four passing TDs and one rushing TD in a playoff game.

Now, Hartstein has locked in another confident against-the-spread pick for Cowboys vs. 49ers. We can tell you he's leaning Over the point total, but he knows a crucial X-factor makes one side of the spread a MUST-BACK! You ABSOLUTELY need to see what it is before locking in any picks of your own.

Who wins the NFC Divisional round game and 49ers vs. Cowboys on Sunday? And what critical X-factor makes one side of the spread a must-back? ... Join SportsLine right now to see which side of the Cowboys vs. 49ers spread to jump on, all from the expert who's an outstanding 14-4 on his last 18 against-the-spread picks involving Dallas!