NFL 'SNF' Week 5: Best bets and preview for 49ers vs. Cowboys

On the offensive side of the ball, the Brock Purdy experience doesn't look to be a fluke. Purdy has thrown for 1,019 yards in four games while completing 72.3 percent of his pass attempts, and he hasn't thrown an interception this season. The former "Mr. Irrelevant" also leads the NFL in quarterback rating and QBR through four weeks.

As for the Cowboys, they haven't had to do much on offense yet because of how dominant the defense has been. Dak Prescott has thrown only four touchdowns through four weeks, but he's tossed just one interception after leading the league last year. 

In a matchup between two game-changing defenses and two highly efficient offenses, which team has the advantage?

'Sunday Night Football' best bets 

Cowboys +3.5 (-108 DraftKings)

Are the 49ers a better team than the Cowboys right now? In all likelihood, yes. But are they 3.5 points better? I'm not convinced.

San Francisco has put up gaudy stats on both sides of the ball, but it's also played four below-average teams in the Pittsburgh Steelers, Los Angeles Rams, New York Giants and Arizona Cardinals. This will be by far the best defense San Fran has played, while the Cowboys have already faced two solid defenses in the New York Jets and New England Patriots.

This feels like a three-point game either way, so the only play is to take the points.

First quarter over 7.5 (-108 FanDuel)

It'd be easy to gravitate to the under in this matchup because of the 19-12 playoff game these two teams played last season, but we're going the other way. The Cowboys are averaging 9.0 points per game in the first quarter, which is the best mark in the NFL through four weeks. Meanwhile, the 49ers rank ninth in the league with 6.8 points per first quarter. 

Kyle Shanahan is a master at drawing up the first scripted drive of the game, and he'll have something special cooked up for this Cowboys defense. Look for both teams to come out firing on the offensive end.