The race to the Super Bowl is getting tighter, and the Divisional Round is the second-to-last step to the big game. The San Francisco 49ers are set to host the Dallas Cowboys at Levi's Stadium on Sunday, and they'll be looking to keep their winning streak alive.

San Francisco is coming off a big 41-23 victory over the Seattle Seahawks in the Wild Card Round. The win in their playoff opener extended the team's winning streak to 11 games, dating back to the regular season.

A big part of the team's success in 2022 was the acquisition of Christian McCaffrey in a trade with the Carolina Panthers. In 10 games with the Niners in the regular season, he finished with 149 carries for 701 yards and six touchdowns. He also added 49 catches for 430 yards and three scores.

While McCaffrey's impact on offense is crucial for the 49ers, the defensive unit also deserves some praise. With that being said, here is the San Francisco 49ers’ X-factor against the Dallas Cowboys, but it is not Christian McCaffrey.

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49ers X-Factor vs. Cowboys: Nick Bosa

In the regular season, San Francisco held opponents 20 points in 14 opportunities. The team ended up winning 12 of those games. Overall, the Niners had the best defense in the league with only 16.3 points allowed per contest.

Additionally, they placed in the top 10 in multiple defensive categories. Their 1,321 rushing yards allowed was the second-best in the NFL and their 20 interceptions were the most by a team in the regular season. Additionally, San Francisco's 44 sacks were good for the top 10 in the league.

While they have stars across the defense, no one stands out more for the 49ers than EDGE rusher Nick Bosa. The defensive end led the NFL with 18.5 sacks, which was also a career-best. Bosa also added 51 total tackles with 41 being solo and 19 tackles for loss. He ended up forcing two fumbles as well.

For his performances, Bosa earned his first First-team All-Pro honor and his third selection to the Pro Bowl.

In the Wild Card Round, he had five total tackles with three solos plus a tackle for loss. Most importantly, he recovered a fumble late in the third quarter when the Niners were leading 23-17. The possession led to a touchdown for San Francisco, and the team maintained a double-digit lead for the rest of the day.

On Sunday, Bosa and the 49ers will have a tough challenge. The Cowboys only allowed 27 sacks in the regular season, the fourth-best mark by an offense in the league. Also, they had 2,298 yards on the ground, good for the top 10.

Against the Tampa Bay Buccaneers in the Wild Card Round, quarterback Dak Prescott was only sacked once. Dallas ended up averaging 6.2 yards per play. For comparison, the 49ers held the Seahawks to 5.3 yards per play.

With Prescott coming off one of the best games of his career with five total touchdowns (four passing and one rushing), San Francisco will need to find a way to pressure him during their Divisional Round matchup. Because of that, now more than ever, Bosa needs to show why he is a contender for the NFL Defensive Player of the Year award.

Although McCaffrey and rookie quarterback Brock Purdy should lead the offense, Bosa will be the anchor of the defense. With the defensive end pressuring Prescott, the Niners will force the Cowboys to bad throws. This could cause many punts, sacks or even interceptions and fumbles.

If Bosa plays as he did in the regular season, San Francisco will have a better chance of beating Dallas. Then, the 49ers will be one step closer to reaching the NFC Championship Game and the Super Bowl.