The Baltimore Ravens and San Francisco 49ers met in a showdown Sunday that provided a reminder of how little anybody knows about the NFL. In the preseason, neither team was considered a serious Super Bowl threat — the 49ers had picked second overall in the draft. In Week 13, they played a taut game in a cold rain that left both at 10-2 and among the favorites to meet in Miami two months from now.

But their dual ascent would have been easy to predict compared with what else happened Sunday. Devlin Hodges led the Pittsburgh Steelers to their sixth win in seven games, effectively knocking out Baker Mayfield and the Cleveland Browns. The New England Patriots are 10-2 but seem as vulnerable as they have been in recent seasons. The Miami Dolphins stunned the Philadelphia Eagles, who are still hanging on in the NFC East because the Dallas Cowboys lost on Thanksgiving to the Buffalo Bills — who are 9-3.

It is, as ever, an impossible league to predict. Here is what to know coming out of the 13th Sunday of the season.

The Ravens are built to win close games. Baltimore had won its past five games by an average of 28 points entering Sunday, all of them by at least two touchdowns. The Ravens’ dominance made it easy to forget how perfectly constructed they are to close out tight games and to thrive in January. They have an elite offensive line, a powerful running game topped with a historically great running quarterback, smart coaches and, in Justin Tucker, perhaps the best kicker in NFL history.

“That’s the G.O.A.T.,” quarterback Lamar Jackson said. “I have all the faith in him.”

The Ravens scored 20 points Sunday, their lowest output of the season, in cold rain at sloppy M&T Bank Stadium against the 49ers’ excellent defense. But it was enough to hand San Francisco its second loss and earn a 20-17 victory because of how they finished.

Baltimore took over on its 35-yard line with 6:23 left. It marched 34 yards in 12 methodical plays, running nine times, pulverizing the 49ers an inch at a time, picking up one fourth down and one third down. The Ravens set up a 49-yard field goal with three seconds remaining. In those conditions, for most kickers, it would have been a risk — in the first half, the 49ers’ Robbie Gould came up well short from 51. But Tucker is on a different level than even the best NFL kickers. He blasted the 49-yarder through the middle of the uprights.

The victory became even bigger Sunday night, when the Patriots’ loss moved the Ravens into position for the AFC’s No. 1 seed. For the NFL’s contenders, the Ravens’ performance had to be demoralizing. It is hard enough to stay close with the Ravens. And if you do, they’re built to beat you anyway.

The Patriots aren’t a Super Bowl-caliber team. The Patriots have been making their detractors and doubters look stupid for two decades, but New England’s 28-22 loss in Houston on Sunday night felt more drastic than past losses which caused knee-jerk reactions that became laughable. First, it happened in December — Bill Belichick does not have the time or flexibility with personnel to fix what ails the Patriots’ offense. Second, it fit a pattern — the Patriots have lost to the past two AFC contenders they have faced.

Do not be fooled by the final score. The Patriots scored two touchdowns in the final minutes and put a brief scare in the Texans, but they were inept all night on offense, scoring three points in the first half and sitting on nine deep into the fourth quarter.

The Patriots’ problem is both obvious and intractable. They don’t have enough talented skill-position players around Tom Brady. They have not recovered from the retirement of Rob Gronkowski and the losses of Antonio Brown and Josh Gordon. The Texans double-teamed Julian Edelman and put a cornerback on running back James White, and the remaining flotsam and jetsam couldn’t provide any separation. “We got to be faster, quicker, more explosive,” NBC cameras captured Brady screaming at his receivers on the sideline. Those are not traits that change between Dec. 1 and the playoffs.

The Patriots, obviously, will not be an easy out in the playoffs. But their path to Miami is likely to include some combination of the Texans, Ravens and Kansas City Chiefs, three offenses that even New England’s defense can’t completely shut down. They are going to have to score points to make the Super Bowl. They have not shown the capacity to do so for three consecutive games.

The Dolphins scored on a mind-bending fake field goal. Let’s hope if Miami gets good in the next few seasons Coach Brian Flores stays this interesting. In the past month, Flores has attempted multiple surprise onside kicks and faked a punt. Sunday, in a 37-31 victory over the Eagles, Flores unveiled perhaps the coolest, zaniest play of the season.

On fourth and goal from the 1, the Dolphins sent their field goal team on the field. But then they lined up in a gonzo formation. Near both sidelines, three linemen lined up with a man behind them. Kicker Jason Sanders lined up in the left slot. Punter Matt Haack, typically the holder, stood behind long snapper Taybor Pepper, who was all alone in the middle of the field, with one Eagle standing up to each side.

Haack took the snap and rolled left. Three Eagles from that side of the field rushed at Haack, allowing Sanders to slip behind them into the end zone, uncovered, for a shovel-pass touchdown. Nobody ever suspects the kicker.

The Titans used a jailbreak field goal block to emerge in the AFC playoff race. Tennessee started slow in Indianapolis, falling behind by 10 points early in the third quarter. The Titans clawed back behind Derrick Henry, who rushed for 149 yards a week after gaining 159, which followed a 188-yard performance.

It was 17-17 when Adam Vinatieri attempted a go-ahead field goal. The Titans blew up the Colts’ protection, with three players bursting through the line. They blocked the kick, and Tye Smith scooped it and returned it for a go-ahead touchdown. The Titans would eventually win, 31-17, cementing them as one of the hottest teams in the NFL.

Since Coach Mike Vrabel replaced Marcus Mariota with Ryan Tannehill, the Titans have gone 5-1 while averaging 30 points. Now they control their future in the AFC South. The Titans (7-5) play the first-place Texans twice in the final three weeks.

The Jaguars have an awkward quarterback situation — and big decisions ahead. Jacksonville signed Nick Foles to an $88 million contract in free agency this offseason to give it stability at quarterback. Twelve games into that four-year deal, the Jaguars face the opposite of stability.

Foles committed turnovers on the Jaguars’ first three drives and led three consecutive three-and-outs before halftime, at which point Jacksonville trailed Tampa Bay 25-0. Coach Doug Marrone benched Foles for rookie Gardner Minshew II, injecting more uncertainty into Jacksonville’s quarterback situation heading into an offseason when everything about the Jaguars seems to be in question.

Foles’s first season has been a disaster not of his own making, but still a disaster. Foles broke his clavicle in Week 1 and yielded to Minshew, whose quirkiness and capability made him a fan favorite and momentary sensation. The Jaguars went 4-4 in Minshew’s eight starts, but the Jaguars went back to Foles once he regained health.

In three games since retaking his job, Foles has led the Jaguars to an 0-3 record, losing by an average of 19 points while gaining a paltry 6.1 yards per passing attempt. It’s not really fair to evaluate Foles based on this season, but the NFL isn’t about fairness. The Jaguars will have to decide whether to trade Foles and move forward with Minshew on a rookie contract.

They will also have to decide who makes that decision. Team president Tom Coughlin and Marrone will both be evaluated this offseason. Since the Jaguars made the AFC championship game and nearly toppled the Patriots in New England two seasons ago, they have gone 9-19 and traded cornerback Jalen Ramsey, one of the best players in franchise history. Owner Shad Khan has some mulling to do.

It’s over for the Browns. The only question left: Will Coach Freddie Kitchens survive? The Browns revived their season with three consecutive victories, and playing the Steelers with third-string quarterback Hodges gave them an ideal opportunity to sneak back into the muddled AFC wild-card picture.

Back in August, the Browns were a chic Super Bowl pick. Sunday, they couldn’t beat Hodges to save their season. The 20-13 loss dropped the Browns to 5-7 while the Steelers improved to 7-5, and though the Browns are still technically alive, the combination of their schedule, their year-long underachievement and the suspension of defensive end Myles Garrett ensures they will be home for January.

How the Browns’ promise unraveled is a complicated matter, but much of the blame falls at the feet of Kitchens, the rookie coach tasked with managing talent and expectations unfamiliar in Cleveland. The Browns have been disorganized and undisciplined, stale on offense and inconsistent on defense. Quarterback Baker Mayfield regressed, wide receiver Odell Beckham Jr. went underutilized, and penalties piled up to preposterous degrees. They were a mess, and the squandered season demands the Browns evaluate whether Kitchens is the right person to salvage things next year.

The Chargers invented another new way to lose. It is an image every bit as reliable as the ticking clock on “60 Minutes”: Philip Rivers flapping his arms and screaming around the line of scrimmage late in the fourth quarter, with his Chargers sitting on somewhere between 17 and 24 points, down by a field goal or so, about to do something crazy, brave, amazing, stupid, unbelievable or all of those things combined.

Sunday’s entry into Rivers’s Pantheon of the Insane happened like this. Down by three, the Chargers turned fourth and one at their 34 into fourth and 11 at their 24 with consecutive false-start penalties. Rather than punting, Rivers heaved a prayer deep to Mike Williams, who made a miraculous catch with one hand and a defender draped on him. The Chargers couldn’t pick up one more first down, settling for a field goal and leaving 14 seconds on the clock.

For most teams, overtime would be assumed. The Chargers live life able to assume nothing. Denver quarterback Drew Lock, a second-round pick making his pro debut, chucked a deep ball to Courtland Sutton. The officials flagged Casey Hayward for pass interference, a seemingly dubious call that set up Brandon McManus’s game-winner from 53 yards.

If someone described the above sequence without identities and asked you to guess the team, you would guess the Chargers. And you would be right. Every one of the Chargers’ eight losses this season have come by eight points or fewer, and all but two of their games have been decided by one score. At 4-8, their season is over. If a handful of plays — most of them bordering on indescribable — had gone differently, they could be a playoff team.

The Chiefs’ defense is turning into something interesting. With Patrick Mahomes running Andy Reid’s scheme with Tyreek Hill and Travis Kelce, the Chiefs require competence, not excellence, out of their defense. Under new defensive coordinator Steve Spagnuolo, they’re starting to get it.

The Chiefs entered Sunday ranked 19th in points allowed and 20th in yards per play, which is just good enough to complement Mahomes and make them a threat in the playoffs. Sunday, they allowed only cosmetic points to the Oakland Raiders in a 40-9 blowout. Juan Thornhill, a rookie second-round safety, confused Derek Carr and intercepted him for a pick-six.

If the Chiefs make any noise in the playoffs, it will be because of their offense. The defense has to be not terrible to give them a chance. And it’s not terrible.

The 2008 Detroit Lions and 2017 Cleveland Browns can rest easy. The Cincinnati Bengals will not join them in infamy as an ­0-16 team after trouncing the New York Jets, 22-6, after Andy Dalton retook the starting quarterback spot. Bengals Coach Zac Taylor got the first win of his career, and it didn’t even cost the Bengals positioning for the No. 1 draft pick — the Washington Redskins and Dolphins both improved from two wins to three. At 2-10, the New York Giants are now the second-worst team in the NFL.

The Jets continued a bizarre season in which they have beaten the Cowboys and Raiders but lost convincingly to the Dolphins and Bengals. Acting owner Chris Johnson has already ensured Coach Adam Gase will return next season, but it has been an uninspiring first act for him in New York.

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