The hottest unit in the league is undoubtedly the Steelers’ offense. Quarterback Ben Roethlisberger followed his masterly six-touchdown performance against the Colts in Week 8 with a six-touchdown showing against the Ravens in Week 9. He is the first player in league history to throw 12 touchdowns over a two-week span, and he now sits among the leaders in most meaningful passing categories. He ranks second in passing yards and completion percentage, third in passing touchdowns and passer rating, fifth in yards per attempt and first in interception rate.

Image The Steelers’ Ben Roethlisberger made league history with consecutive six-touchdown games. Credit... Gene Puskar/Associated Press

It is an M.V.P.-caliber season for Roethlisberger, but he might not even be the most valuable player on his own offense. Wide receiver Antonio Brown is having another magnificent season: He leads the N.F.L. in both receptions and receiving yards. Among wide receivers, only Randall Cobb (nine) has more than Brown’s eight receiving touchdowns. (Brown has also thrown for one score.) Over the last three weeks, the rookie Martavis Bryant has benefited from all the attention defenses are paying to Brown by catching five touchdowns. The Steelers (6-3) remain a work in progress on defense, but their passing attack could be enough to guide the team to the postseason.

But the team atop the toughest division in football is the Bengals. Because they won the division in 2013, it might not be surprising to see them playing well. But the Bengals (5-2-1) have been without the top wide receiver A. J. Green for most of the season, tight end Tyler Eifert for all but one game and Marvin Jones (who was second on the team to Green last season in receiving yards) for the entire year. While Green is back, running back Giovani Bernard is banged up. Even the offensive line — a strength point in 2013 — has taken a step back this year. But through it all, the much-maligned quarterback Andy Dalton has steadied the ship.

Dalton is posting career-best numbers in completion percentage, interception rate and sack rate, which means he is playing at a consistent level and avoiding negative plays. That has been necessary as the defense has fallen off: After allowing only 11 points per game through three weeks, Cincinnati has allowed 30.8 points per game over its last five games. The Bengals, despite being in first place, have the worst point differential among A.F.C. North teams.

As a result, the league’s toughest division is also its most unpredictable. All four teams have reasons for optimism: The Bengals are in the pole position and also have the best division record at 2-0. The Steelers are the hottest team right now, while the Ravens are the most balanced. And the Browns will get Gordon back for the final six weeks of the year. After nine weeks, we don’t yet know where the teams will wind up ranked inside the division. But we have a pretty good idea where this division ranks in the N.F.L.