If it feels like we still don’t know how good the Minnesota Vikings are after 15 weeks of football, it’s probably because … we still don’t. With their playoff hopes on the line Sunday, the Vikings cruised past the Miami Dolphins — a team whose own playoff future was in flux — in a 41-17 rout. According to the FiveThirtyEight Elo prediction model, Minnesota now has a 58 percent chance of making the postseason, giving the Vikings an edge in playoff odds over Philadelphia (39 percent), Washington (11 percent) and Carolina (less than 1 percent) in the battle for the NFC’s second and final wild card spot.

And yet, the Vikings have been one of the tougher teams to figure out this season. (As if they would have it any other way.) Surprise Super Bowl contenders last year, they pre-emptively moved on from journeyman quarterback Case Keenum to the highly paid Kirk Cousins — a move that seems to get second-guessed on a weekly basis. But every time this team is written off, Minnesota has responded with a performance like Sunday’s win. So why have these Vikings been so mystifying? Did the recent firing of offensive coordinator John DeFilippo do anything to fix the team’s malaise? And is Minnesota still in a position to realistically contend for that elusive first Super Bowl ring in franchise history?

One reason the Vikings have seemed so disappointing is that expectations were very high after last season’s miraculous run to the NFC title game. This time last year, Minnesota’s Elo rating was 1639, tied for fourth-best in the NFL. And before the 2018 season began, its Elo was 1602 — the highest it had been before any season since 1999. (That year, the Vikings went 10-6 and lost in the divisional round, which was also disappointing relative to expectations.) Compared with either lofty standard, the Vikings’ current rating of 1560 — 11th-best in football — hasn’t really hit the mark. Among teams that are still above a 1500 (i.e., average) Elo right now, only Philadelphia has fallen short of its preseason rating by a wider margin than the Vikings have.

Minnesota hasn’t been able to gain much ground in Elo in part because it only ever beats the opponents it’s supposed to. (Except when it loses to them as 16½-point favorites.) The Vikings’ wins have come against a group that has a combined .313 winning percentage in games against other opponents, which is second only to the Cardinals (.269) for lowest in the league in terms of opponents a team has beaten. Meanwhile, the teams who have beaten the Vikings have a combined winning percentage of .704, fourth-highest in the league. (Their tie was against a Packers team with a .385 winning percentage in other games.)

Minnesota beats the bad teams, loses to the good ones Average opponent winning percentage* for 2018 NFL teams, by team’s outcome in game Team Wins Opp. WPct Team Losses Opp. WPct Arizona 3 .269 Kansas City 3 .795 Minnesota 7 .313 L.A. Rams 3 .741 Washington 7 .329 L.A. Chargers 3 .718 Atlanta 5 .329 Minnesota 6 .704 Seattle 8 .331 Seattle 6 .679 * Excluding games against the team in question. Source: ESPN.com

A vaguely above-average team that can only beat inferior opponents is not what the Vikings were envisioning when they signed Cousins to that massive contract — which, of course, the 2018 Vikings’ entire season will ultimately be viewed as a referendum on. Though it was later surpassed by a number of other deals, Cousins’ three-year, $84 million contract was the largest in NFL history when he put pen to paper in March. With it came the weight of the franchise and the responsibility to improve on last year’s offense, which was seen as the team’s weakness relative to its top-ranked defense. And by that standard, Cousins has failed. This season, Minnesota is down from 10th in points per game to 17th; from tied for 11th in yards per play to a tie for 14th; from eighth in expected points added to 23rd.

Cousins’ individual passing numbers aren’t so different from Keenum’s a year ago, though. In fact, Cousins beats his predecessor’s 2017 stats in terms of completion percentage (70.5 percent to 67.6), touchdown percentage (4.8 percent to 4.6) and passer rating (99.0 to 98.3), while sticking relatively close on interception percentage (1.8 percent vs. 1.5). The only area in which Cousins hasn’t really matched Keenum is sack rate — Minnesota’s 2018 starter has hit the deck on 5.9 percent of his dropbacks (compared with 4.4 percent for Keenum in 2017). Even granting that passing standards have gotten higher since last year, Cousins has done a good job of roughly approximating Keenum’s 2017 output according to Pro-Football-Reference’s advanced passing indices, which scale everything relative to a league average of 100 (where 15 points in either direction equals one standard deviation of performance):

Cousins has held the Vikings’ passing stats steady Advanced passing index numbers for Minnesota Vikings starting QBs from 2017 (Case Keenum) and 2018 (Kirk Cousins) Adv. Passing Index* Year Player Record Cmp% Y/A TD% Int% Sack% QB Rtg ANY/A 2017 Case Keenum 11-3-0 115 104 102 115 114 111 111 2018 Kirk Cousins 7-6-1 124 100 103 109 105 111 105 2018 Case Keenum 6-8-0 95 92 85 100 104 90 92 * Advanced passing indices are scaled where 100 is league average, and 15 points in either direction represents 1 standard deviation. Source: Pro-Football-Reference.com

And that’s to say nothing of Keenum’s own nosedive in performance after leaving Minnesota for Denver, where he has strongly reverted back to the form he’d shown in four seasons leading up to 2017 as a mediocre spot-starter. Keenum’s passer rating this season (82.1) has a lot more in common with his 78.4 career mark before 2017 than the out-of-nowhere 98.3 rating he posted last season. Had the Vikings brought Keenum back, their offense would likely be in even worse straits than it has actually been this season.

Instead, Minnesota paid the going rate to Cousins, easily the best available option on the QB market, in order to keep the passing game afloat — and in the big picture, that plan basically worked. But Cousins and the Vikings haven’t been able to convert those raw numbers into points as readily as they did last season. Minnesota already has six more turnovers this year than last; it’s also fallen from the league’s third-best third-down conversion rate to 19th, and from the ninth-best red-zone scoring percentage to 21st. (Cousins’s own penchant for taking ill-timed red zone sacks — he’s tied for the third-most in the NFL — hasn’t helped there.)

The offense boasts plenty of talent between Cousins, running backs Dalvin Cook and Latavius Murray — a pair collectively averaging more yards per carry this year (4.4) than last (4.1) — and wide receivers Adam Thielen and Stefon Diggs, who are on pace to become the 68th teammates in NFL history to each average at least 70 receiving yards per game in a season. Yet the moments of excellence have been few and far between. In Weeks 11 through 14, Minnesota averaged just 15.3 points per game, culminating in a 7-point disaster against the Seahawks that ultimately cost DeFilippo his job.

It wouldn’t be a Vikings season without a hint of hope, however — this time in the form of that 41-point outburst against Miami under new play-caller Kevin Stefanski. Tasked with running the ball more, Stefanski had Cousins hand off 40 times and throw just 21 passes, a reversal of the team’s tendency toward the pass on nearly 70 percent of plays under DeFilippo. Some of the newfound run-heavy game plan owes to the quick 21-0 lead Minnesota jumped out to over the Dolphins, but it also represents a change in offensive philosophy for a team generally built to pass the ball.

Said tight end David Morgan after the Miami game: “In days leading up, [Stefanski] was talking about kind of the identify we wanted to be and be physical and kind of run the ball really well and kind of just set it how we used to run it.”

We’ll find out over the next two weeks how much the Vikings’ new identity sticks — and, perhaps more importantly, how well it works. Their next game, against Detroit, carries plenty of playoff implications not just for fans in Minnesota but also those in Philadelphia and Washington. That’s a big part of why, according to our combination of matchup quality (i.e., the harmonic mean of the teams’ Elo ratings in each game) and game importance (how likely it is to swing every team’s odds of making the playoffs), Vikings-Lions is the fourth-best game of Week 16:

The best matchups of Week 16 Week 16 games by the highest average Elo rating (using the harmonic mean) plus the total potential swing for all NFL teams’ playoff chances based on the result, according to FiveThirtyEight’s NFL predictions Playoff % Playoff % Team A Current Avg. Chg* Team B Current Avg. Chg* Total Change Game Quality BAL 40.7% +/-29.2 LAC 100.0% +/-0.0 58.6 1614 PIT 74.7 11.6 NO 100.0 0.0 24.1 1664 PHI 38.9 18.6 HOU 99.7 0.2 38.3 1569 MIN 57.5 25.9 DET 0.0 0.0 52.9 1510 TEN 46.5 19.0 WSH 11.0 10.8 59.7 1495 SEA 96.4 3.3 KC 100.0 0.0 7.6 1624 DAL 95.2 7.2 TB 0.0 0.0 14.9 1493 NE 99.5 0.9 BUF 0.0 0.0 2.6 1505 IND 34.0 6.4 NYG 0.0 0.0 13.6 1477 CHI 100.0 0.0 SF 0.0 0.0 3.0 1492 MIA 5.0 3.9 JAX 0.0 0.0 9.0 1421 CAR 1.0 0.8 ATL 0.0 0.0 2.5 1492 CIN 0.0 0.0 CLE 0.0 0.0 4.4 1415 ARI 0.0 0.0 LAR 100.0 0.0 1.7 1464 GB 0.0 0.0 NYJ 0.0 0.0 1.8 1402 DEN 0.0 0.0 OAK 0.0 0.0 1.6 1398 Game quality is the harmonic mean of the Elo ratings for the two teams in a given matchup. Total Change adds up the potential swing in playoff odds for every team in the league (not just the two teams listed). *Average change is weighted by the likelihood of a win or loss. (Ties are excluded.) Source: ESPN.com

That will set up what might be an even more crucial matchup in Week 17 against the Bears, where the fate of this baffling Vikings squad could be decided once and for all. In a way, the Vikings were always primed to regress in 2018 — it was just a question of how much. Their defense was unusually great last year, and it has fallen from first in points allowed last season to 12th this year. The offense was going to need to sustain its efficiency despite breaking in a new QB and coordinator. The expectations might have been unrealistically high; either way, they haven’t been consistently met. But despite everything, the Vikings have still given themselves a chance to play their way into the postseason. Although their destiny could be redemption or it could be doom — at least they control it.

FiveThirtyEight vs. the readers

For up-to-date playoff probabilities and Super Bowl odds, Check out FiveThirtyEight’s Elo ratings in our NFL prediction interactive. It simulates the rest of the season 100,000 times and tracks every team’s chances of winning it all. You can also pick against the Elo algorithm in our prediction game, so give it a shot and try to climb up our giant leaderboard.

Based on data from the prediction contest, here are the matchups in which Elo made its best — and worst — picks against the field of readers last week:

Elo’s dumbest (and smartest) picks of Week 15 Average difference between points won by readers and by Elo in Week 15 matchups in FiveThirtyEight’s NFL prediction game OUR PREDICTION (ELO) READERS’ PREDICTION PICK WIN PROB. PICK WIN PROB. Result READERS’ NET PTS DEN 69% DEN 57% CLE 17, DEN 16 +12.4 – HOU 64 HOU 72 HOU 29, NYJ 22 +3.2 – KC 66 KC 62 LAC 29, KC 28 +2.8 – NO 69 NO 72 NO 12, CAR 9 -0.6 – DET 51 BUF 50 BUF 14, DET 13 -0.9 – DAL 53 DAL 52 IND 23, DAL 0 -1.1 – TEN 51 TEN 51 TEN 17, NYG 0 -2.5 – BAL 76 BAL 74 BAL 20, TB 12 -2.6 – ATL 73 ATL 71 ATL 40, ARI 14 -2.7 – JAX 60 JAX 63 WSH 16, JAX 13 -5.3 – CHI 74 CHI 69 CHI 24, GB 17 -5.4 – MIN 72 MIN 66 MIN 41, MIA 17 -6.2 – CIN 66 CIN 59 CIN 30, OAK 16 -7.4 – SEA 71 SEA 75 SF 26, SEA 23 -8.2 – PIT 51 NE 56 PIT 17, NE 10 -9.7 – LAR 70 LAR 76 PHI 30, LAR 23 -10.2 – Home teams are in bold. The scoring system is nonlinear, so readers’ average points don’t necessarily match the number of points that would be given to the average reader prediction.

Just when readers pulled closer to the Elo model in Week 14, our algorithm struck back in Week 15, winning by an average of 44.4 points over the typical reader. The field picked up points for believing in the Browns against the Broncos — or at least considering Cleveland less of an underdog. (Cleveland won, continuing its incredible turnaround season.) But that was one of the week’s few bright spots for readers, as Elo had the better pick on average in 13 of 16 matchups, including Pittsburgh’s upset win over New England and the Eagles’ victory at the L.A. Rams.

Despite the carnage, congrats are in order to James Hare, who won Week 15 with a tally of +123.9 points. And let’s give yet another round of applause to Greg Chili Van Hollebeke, who stayed at No. 1 for the season with +960.2 points. Thanks to everyone who has been playing — and if you haven’t, get in on the action before it’s too late! You can make picks now and still try your luck against Elo, even if you haven’t played yet.

Check out our latest NFL predictions.