When was the last time a Wild Card round matchup featured two teams with such dramatically different thresholds for success? The Steelers believe they are legitimate Super Bowl contenders, the AFC's best chance to knock off the Patriots; anything less than the AFC Championship Game would be a major disappointment for them.

Meanwhile, the Dolphins are the team that everyone's a little baffled to see here, especially since losing its starting quarterback. If all goes according to plan, the Steelers will use this game as a warmup for a thrilling matchup at Arrowhead Stadium next week against the Chiefs, and the Dolphins will just be pleased as punch they were here in the first place. But if it doesn't go according to plan, the whole order of the AFC will be upended. 

No. 6 Miami Dolphins (10-6) at No. 3 Pittsburgh Steelers (11-5)

When: Sunday, 1:05 p.m. ET, CBS
Where: Heinz Field, Pittsburgh, Pa.
Most recent meeting: Oct.16: Dolphins 30, Steelers 15. Ben Roethlisberger had a rough game, and Le'Veon Bell hadn't quite worked himself back to game shape yet. 
Simple Rating System numbers: Pittsburgh 0.2, Miami -1.3
Current line: Steelers by 9 1/2
Ranking among four first-round matchups: Third. The biggest "mismatch" in the AFC, and maybe the whole playoffs. But it's funny how that tends to work out.

How the Steelers can win

1. Let Bell go nuts. This is the star running back's first playoff game, and he should be revved up against a Dolphins defense that, well, has not been shy about giving up some yards. Bell has the opportunity to have a pretty epic playoffs, and this is the ideal game for that to begin. He's rested after everybody got last week off, he's healthy and he's highly motivated. If you have a fantasy playoff league, he's the No. 1 pick.

2. The defense might think about showing up. The Steelers' run defense, which had struggled most of the season, had improved in the second half before giving up wayyyy too many yards to the Browns in Week 17. Sure, it was Week 17, no one was really playing all that hard, but still: Time to tighten that up. (Stephon Tuitt's return should help.) The Steelers' plan is to score so many points in these playoffs that their defense doesn't have to be perfect. But it has to be better.

3. Get ahead early. Roethlisberger, Bell and Antonio Brown have never played in a playoff game together; they're rarely even healthy at the same time. They will be shot out of a cannon to begin this one. If they can get on the board early and often, the young Dolphins could be a little too stunned to recover: Bell could run the rest of the game out himself.

How the Dolphins can win

1. Roethlisberger gets injured. I don't mean to be flippant about a man's health, but come on, this is the NFL: Knocking the other team's quarterback out of the game is practically on the NFL insignia now, isn't it? Anyway, that's how the Dolphins beat the Steelers back in October. Roethlisberger suffered a knee injury in the first half, and because he's Roethlisberger, he tried to play through it in the second half. He couldn't, and the Dolphins took advantage. The Steelers are so excited about all their weapons. The best way to stop them is to never allow them to deploy them.

2. Jay Ajayi left, right and center. Is his shoulder, which Ajayi had X-rayed after the season-ending loss to New England, OK? Only one way to find out! The Dolphins don't have a ton of weapons anyway, but Ajayi has been terrific: He's the main reason they're here. Miami will need to play a ball-control game to even have a chance, but Ajayi is the linchpin of that whole strategy. This is his first playoff game too: No better time to introduce himself to America.

3. Pray for gold from Matt Moore. Look, if you've got to go into a playoff game with a backup, there are worse guys than Moore. This is a grizzled veteran, with starting experience; he threw for 2,500 yards just five years ago. You'd rather have him than Matt McGloin or Brock Osweiler, that's for sure. Can he match Big Ben and company touchdown for touchdown? Probably not. But there's upside here, and Moore's unlikely to make a massive mistake either. The Dolphins have one of the better backup quarterback situations in the league. Which is good, because they suddenly need one.

Prediction

The assumption that the Steelers are just going to roll is a pervasive one, but I wouldn't be so sure. The Dolphins are a young, opportunistic team that won't be intimidated by going into Heinz Field, and they have a quarterback who now has a chance to salvage a once-disappointing career. Miami is just the sort of funky team that throws an odd wrench into the playoffs we thought we all had figured out. The triumvirate of Roethlisberger, Bell and Brown is too much not to pick Pittsburgh … but here's betting this is closer than anybody thinks.

Steelers 34, Dolphins 30.

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