(AP Photo/Don Wright)

The Baltimore Ravens will once again face the New England Patriots in the playoffs, and they are perhaps the one team Coach Bill Belichick did not want to see.

The Patriots have been installed as seven-point favorites at multiple sports books, but the Ravens have won twice at New England as underdogs in the postseason. The first was in 2009 during the wild-card round and again three years later in the 2012 AFC title game. Baltimore lost as seven-point underdog in New England during the 2011 AFC championship.

Everybody knows the history,” Ravens linebacker Terrell Suggs said. “We’re going to play a football game, and it’s the Ravens versus the Patriots. Everybody knows the story lines with this.”

The fact the Ravens have made it this far should not come as a surprise. Back in early November, advanced stats pointed to Baltimore making a playoff run despite sitting in last-place of the competitive AFC North.

Perhaps it is surprising to see Baltimore at the top of the standings, but it shouldn’t be: they may have a 5-4 record but they have the third highest point differential in the league, and that correlates to winning games.

Here are three reasons the Ravens will continuing their surprising run to the AFC title game:

They are tough to run against

The Ravens allowed the third fewest yards per carry during the regular season (3.6) and were rated as the third best run-stopping unit by the game charters at Pro football Focus during the regular season.

Plus, Baltimore hasn’t allowed a 100-yard rusher in the past 27 games, the longest active streak in the NFL.

The player to watch is Brandon Williams, who has been superb at stopping the run this season. Among defensive tackles taking at least half of their teams snaps, only the Jets’ Damon Harrison (31) has more stops against the run than Williams (29). Williams was also instrumental in the Ravens’ most recent victory over the Pittsburgh Steelers.

Breakdown: Last year’s third round pick has in some senses provided the Ravens an upgrade at two positions this season and put in another strong display last night limiting the Bell-less Steelers’ ground attack. Providing a stout and active run defender at the nose tackle position Williams has allowed Ngata to return to a defensive end spot ensuring that, in spite of his suspension, the Ravens did not notice the departure of Arthur Jones.

Signature Stat: Williams had three stops in run defense last night adding to the 29 he had in the regular season, a mark bettered by only Bennie Logan (33) and Damon Harrison (31).

They get pressure on the quarterback

No team was better at getting to the quarterback than the Ravens. They had 49 sacks for a total loss of 362 yards and were the highest rated pass rushing team by Pro Football Focus. Three of their linebackers, Pernell McPhee, Terrell Suggs and Elvis Dumervil, ranked in the top five for most total pressure among linebackers playing in a 3-4 defensive scheme.

That pressure could knock Patriots quarterback Tom Brady from his lofty playoff perch. For example, when not under pressure this season, Brady had a 113.1 passer rating. It was less than half that this season with defenders in his face.

Joe Flacco is at the top of his game

The Ravens quarterback finished eighth in ESPN’s Total Quarterback Rating metric (67.3) , which incorporates the contexts and details of throws and what they mean for wins. He leads the league in QBR during this year’s playoffs after the victory over Pittsburgh.

Flacco also stretches the field, ranking fifth in accuracy percentage (50.0 percent, which includes dropped passes) on passes 20 or more yards downfield among quarterbacks making at least half of their team’s passing attempts. He was rated above average on all throws traveling 10 or more yards through the air.

Joe Flacco passes by direction, 2014 regular season (Source: Pro Football Focus)

He’s unbelievable,” said Ravens offensive lineman Gino Gradkowski. “He definitely doesn’t get the credit he deserves, and yeah, he isn’t fazed by anything. He’s the same no matter what the situation is, and we feed off of that.”

Why the Ravens won’t win: Rob Gronkowski

Perhaps the biggest challenge facing this Ravens defense is Patriots’ tight end Rob Gronkowski.

Gronkowski wasn’t suited up for either the 2012 AFC championship game or last year’s regular season contest because of injury. However, this year the Pro Bowl tight end will be on the field, and that could cause a matchup problem for Baltimore.

Gronk caught 82 passes for 1,124 yards and 12 touchdowns this season and the Ravens ranked 20th in the league against the opposition’s tight end, allowing nearly seven passes and 49 yards per game, on average.

The Ravens secondary was rated 18th in pass coverage and while inside linebacker C.J. Mosely has been solid in his rookie campaign, one area he can improve on is in pass coverage. He allowed the fourth most yards per cover snap (1.2) among inside linebackers this season (minimum 50 percent of the team’s snaps) and allowed an opposing passer rating of 100.6 in coverage.

“We’ve got to play well,” Brady said. “Baltimore’s got to play well if they want to win. That’s just the way it goes.”