In preparation for the 2015 NFL season, FiveThirtyEight is running a series of eight division previews, each highlighting the numbers that may influence a team’s performance (including projections and rankings based on ESPN’s preseason Football Power Index). Today we focus on the AFC North, where Baltimore, Cincinnati and Pittsburgh have all taken the division title twice over the past six seasons. Will the defending-champ Steelers hand it off again this year? And can the Browns finally break into that group?

Baltimore Ravens

2014 Record: 10-6 | 2015 Projected Wins: 9.0 | Playoff Odds: 54.7%

Offensive Rank: 15th | Defensive Rank: 5th | Special Teams Rank: 2nd

A slight favorite in the AFC North according to ESPN’s preseason Football Power Index (FPI) ratings, Baltimore is more likely than not to make its seventh playoff appearance since 2008. In part, that’s because general manager Ozzie Newsome is playing his own brand of Moneyball. One of his favorite strategies: using free agency to build depth and plug roster holes, rather than trying to sign big-name players at a premium. It’s an approach that keeps the Ravens out of boom-and-bust rebuilding cycles, and keeps generating tickets to the Plinko game that is the NFL playoffs.

For instance, Baltimore needed to address its weakness at secondary this offseason. Although the Ravens were tough against the run and consistently put pressure on opposing QBs, they also allowed the league’s 10th-most expected points added (EPA) through the air because injuries forced them to field a handful of scrap-heap defensive backs. So Newsome added cornerback Kyle Arrington and safety Kendrick Lewis in free agency to bolster the secondary — moves he could afford to make because of cap room freed up by trading defensive tackle Haloti Ngata for draft picks. The deft deal-making is a big reason experts think Baltimore will reclaim elite-defense status this season.

Another signature Newsome move was to let free-agent wide receiver Torrey Smith walk, rather than paying the $22 million sticker price he was eventually guaranteed by San Francisco. While other teams shell out for expensive free-agent receivers such as Smith, Vincent Jackson and Mike Wallace, Newsome has had success with cheaper options. Take Steve Smith, whom the Ravens were able to sign on the cheap a year ago because of his advancing age (he was 35 last season). All Smith did in his Baltimore debut was produce one of the top receiving seasons in Ravens history — and help quarterback Joe Flacco post the best Total Quarterback Rating (QBR) of his career.

Even running back Justin Forsett, whose breakout season lifted Baltimore’s yards per carry from last in the league in 2013 to a tie for sixth last season, was paid only $730,000 a year ago — a pittance by RB standards. Forsett got a raise for 2015 but should benefit from another secret weapon smart teams often use: continuity. All five starters on the Ravens’ offensive line are also returning, and incoming offensive coordinator Marc Trestman is expected to keep predecessor Gary Kubiak’s running scheme.

Newsome appears to recognize a few fundamental truths about the NFL: namely, that bank-breaking offseason pickups are rarely worth the trouble and that teams are better off using their money to build depth and bolster multiple positions. It’s a formula that has served the Ravens well over the years and should continue to pay off in 2015.

Cincinnati Bengals

2014 Record: 10-5-1 | 2015 Proj. W: 8.4 | Playoff Odds: 42.1%

Off. Rank: 14th | Def. Rank: 12th | S.T. Rank: 8th

FPI predicts that the Bengals will be solid again in 2015, and one of the primary reasons is continuity. Twenty-one of their 22 starters are back from a year ago, which ties for the second-most returning starters any NFL team has carried into a season since 2006. Plus, prodigal defensive end Michael Johnson returns after a season in Tampa Bay, and linebacker Vontaze Burfict might (eventually) come back from the knee injury that cost him most of 2014.

While researching FPI, we found that consistency like this, especially when the team is already decent — as the Bengals were last year — is a small but reliable predictor of success. And in the absence of a first-class quarterback, Cincinnati needs all of these small things to go its way if the team wants to stay competitive.

Bengals starting quarterback Andy Dalton has a lifetime QBR of 51, which pretty much makes him the definition of average. (QBR is scaled where the league-wide mean is 50.) Fans and observers have spent years wondering if Dalton can become a top passer, but four seasons of consistently middling numbers probably suggest that we’ve seen his best. He’s dependable, and even good enough to make a winner out of a team if it surrounds him with talent. But rarely do quarterbacks blossom into something new after four full seasons in the NFL.

So instead of counting on Dalton to be great, Cincinnati has built a balanced roster that doesn’t need a star turn at QB. Wideout A.J. Green, for instance, picks up the slack by serving as Dalton’s target more than 30 percent of the time, one of the highest shares for any receiver in the league. Although Dalton played well enough to win two of the three games Green missed last season, it would be unwise to think the Bengals offense would prosper for long without Green’s ability to stretch defenses downfield.

And defensively, FPI projects the Bengals to bounce back after a down year in 2014. Cincy’s defense had allowed the NFL’s second-fewest overall EPA and fifth-lowest rate of yards per attempt two years ago, but they fell to 16th and 20th, respectively, after the departure of defensive coordinator Mike Zimmer a year ago. Losing a coordinator can be surprisingly traumatic for a defense (more on this later), so they should be better in Paul Guenther’s second season at the helm.

Continuity, on both the roster and coaching staff, is one of several small factors Cincinnati will have to rely on this season. Because unless, by some miracle, Dalton turns into a top passer, the Bengals need all the advantages they can get.

FiveThirtyEight is previewing the 2015 NFL season ahead of the first game of the year. Check out our coverage of every division »

Pittsburgh Steelers

2014 Record: 11-5 | 2015 Proj. W: 8.3 | Playoff Odds: 41.4%

Off. Rank: 9th | Def. Rank: 24th | S.T. Rank: 4th

The Steelers had a very un-Steeler-like team in 2014. The offense was white-hot: Antonio Brown led all NFL receivers in fantasy scoring by a wide margin, Le’Veon Bell finished second among running backs, and Ben Roethlisberger ranked fifth among quarterbacks. The defense, on the other hand, was full of holes, as age and free agency caused a unit once nicknamed the “Steel Curtain” to allow the league’s third-worst rate of yards per play.

Pittsburgh still used that bizarro-world formula to squeak past its rivals for the division crown. But it doesn’t bode well as a blueprint for sustainable winning, because there are reasons to think the defense won’t rebound even as the offense falls back to earth.

By virtue of regression to the mean, we usually expect defenses to bounce back from uncharacteristically bad seasons, but Pittsburgh’s situation is complicated by the departure of legendary defensive coordinator Dick LeBeau. When developing FPI, we found that defensive coordinators have a similar (albeit smaller) impact on defense as quarterbacks do on offense — namely, that when a team has a returning coordinator, its defensive performance tends to be better and more consistent between seasons. Conversely, when a new coordinator comes in, the defense usually declines a bit and generally is harder to project. So it’s difficult to say whether the 2015 Steelers will be any better defensively than the 2014 team.

And Pittsburgh might not be able to afford another down defensive year. Although the Steeler offense was surprisingly strong in 2014, it’s probably not realistic to expect a repeat performance — most obviously because Bell will be suspended for the season’s first two games, but also because the team is unlikely to be as healthy as it was last season. Not only was Pittsburgh’s offensive “injury score” the lowest of any team a year ago, but the team also lost less than half as much playing time to injury as the average NFL offense from the past nine years. It’s highly unlikely that they’ll be so fortunate again.

This doesn’t necessarily mean Pittsburgh needs a complete rebirth of the Steel Curtain defense. (The FPI projections still point to the Steelers being a top-10 team, after all.) But with Baltimore and Cincinnati each boasting a slightly higher probability of winning the division, the defense probably has to improve if the Steelers want to repeat as AFC North champs.

Cleveland Browns

2014 Record: 7-9 | 2015 Proj. W: 6.2 | Playoff Odds: 9.7%

Off. Rank: 31st | Def. Rank: 11th | S.T. Rank: 14th

As usual, the Browns’ quarterback situation is dismal. Backup Johnny Manziel gets most of the headlines despite (or, perhaps, because of) a spectacularly trying rookie campaign, but new starter Josh McCown isn’t much better. The 36-year-old journeyman showed unexpected flashes of brilliance in eight games as a Bear in 2013, but he returned to form — ranking second-worst in the NFL in QBR — with the Buccaneers last season. Judging from the rest of his career, it would be unrealistic to expect much more from McCown in 2015.

We all know that the NFL is a passing league, so Cleveland’s QB predicament puts them at a disadvantage. But if there’s any good news for the Browns, it’s that you don’t necessarily need a great passing attack to build a winning team. And with McCown and Manziel unlikely to lead the Browns out of the quarterback wilderness, it falls upon the team’s defense to provide an edge instead.

The Browns return nine starters from what was an effective, and unusual, defense in 2014. Typically, defenses that limit opponents’ passing also have an edge against the running game, and Cleveland was excellent versus the pass — it was third-best in EPA allowed on passing plays, trailing only the Texans and Bills. But the Browns had trouble slowing down opposing runners. Against rushing plays, they ranked 31st in EPA allowed, ahead of only the Saints.

Again, the NFL is a passing league, so Cleveland had a top-10 defense despite its weakness against the run. But given the Browns’ lack of offensive playmakers, their defense can’t afford to have any vulnerabilities if they hope to win games. That’s why Cleveland drafted nose tackle Danny Shelton 12th overall and added defensive lineman Randy Starks in free agency, with an eye on getting tougher against the run and building an elite all-around defense.

It’s an unconventional formula for team-building, but a roster engineered to keep the score low and close can make for upsets. Just last year, the Buffalo Bills used a similar blueprint to win nine games despite having the league’s fifth-worst offense. So if the Browns defense is better than their offense is bad, and they get a few lucky bounces of the ball on special teams, Cleveland might have a winner for just the third time since the franchise was reborn in 1999.

Read more: 2015 NFL Previews