It was certainly a wild Week 1 of the 2018 NFL season. The biggest underdog on the schedule found a way to win, while a couple of other heavy underdogs experienced devastating losses. Some of the league’s best quarterbacks had big performances in their season openers, though questions remain going forward.

What did we learn from all of Sunday’s games? Here are five takeaways from Week 1:

The Buffalo Bills are who we thought they were

No team entered Week 1 with more negative buzz than the Bills, who have the league’s worst Super Bowl odds. Starting the year with lower expectations than anyone, all Buffalo did Sunday was finish on the wrong end of the afternoon's most one-sided game.

The game between the Bills and Baltimore Ravens was essentially over at halftime when the Ravens had a 26-0 lead. A fourth-quarter field goal allowed Buffalo to avoid a shutout as they were defeated 47-3 in an embarrassing loss. Nathan Peterman didn’t make it through the whole game, being replaced after going 5-18 for 24 yards and two interceptions. Josh Allen posted a 56.0 passer rating in his debut, going 6-15 for 74 yards and no scores. Buffalo’s quarterbacks were sacked six times, and the Ravens ended the game with 216 more total yards than the Bills.

The Bills have a decision to make at quarterback. Peterman isn’t the answer, but Allen is their future and could be in trouble behind a bad offensive line. Whoever gets the call in Week 2 will probably be starting for the worst team in football.

Andrew Luck looks good with room for improvement

Even though he was declared healthy, there were still questions regarding Luck’s shoulder in the preseason. The quarterback passed his first test Sunday in the Indianapolis Colts’ 34-23 loss to the Cincinnati Bengals.

Luck played well in defeat. He certainly wasn’t perfect, and things started off poorly with a red zone interception, but he finished with a career-high 39 completions for 319 yards, two scores and just the one pick. Luck did hit Eric Ebron with a 26-yard touchdown pass early in the second quarter that was right on the money, though most of his throws were of the short variety. Only two of Luck's 53 pass attempts traveled more than 20 yards in the air, and it’ll be interesting to see if the quarterback airs the ball out more in the coming weeks.

As is often the case with Indianapolis, a strong performance by Luck wasn’t good enough to give the Colts the win. A poor defensive effort and a late fumble cost them the game. Luck’s shoulder is near the bottom of the list of the team’s issues.

Andrew Luck Indianapolis Colts Andrew Luck #12 of the Indianapolis Colts pass the ball in the game against the Cincinnati Bengals at Lucas Oil Stadium on September 9, 2018 in Indianapolis, Indiana. Photo: Bobby Ellis/Getty Images

Points could be hard to come by in the NFC East

There was a similar theme in all four games that included an NFC East team. None of those contests featured more than 35 total points, and those kinds of offensive struggles could plague the division for much of the year.

The Philadelphia Eagles only scored 18 points behind Nick Foles in their season-opening victory, and there’s a chance Carson Wentz could miss the first month while still recovering from last year’s torn ACL. Saquon Barkley and Odell Beckham Jr. will break their share of big plays, but the New York Giants still have a mediocre quarterback playing behind a poor offensive line. The Dallas Cowboys had no semblance of a passing game in their 16-8 loss to the Carolina Panthers. The Washington Redskins had the best Week 1 performance, beating the Arizona Cardinals 24-6 after being projected to finish in last place.

Let’s see what the Cowboys and Giants can do when they meet on “Sunday Night Football” in Week 2 after facing two top defenses in Week 1. Philadelphia reportedly hopes Wentz will soon be cleared for contact to potentially return in Week 3.

Jacksonville and Minnesota still have elite defenses

The Jacksonville Jaguars and Minnesota Vikings had the NFL’s two best defenses a season ago, making it all the way to their respective conference title games. If Week 1 was any indication, the two units could be just as good in 2018.

Saquon Barkley’s highlight-reel 68-yard run was the only touchdown the Jaguars allowed in their 20-15 road win over the Giants. The team put constant pressure on Eli Manning and held the running game in check on all but one play. Minnesota made Jimmy Garoppolo look nothing like the quarterback that received so much hype in the offseason. He completed fewer than 50 percent of his passes, was sacked three times and threw three interceptions in the San Francisco 49ers’ 24-16 defeat.

The Jaguars are alone atop the AFC South, and the defense will have to carry them this season. With Kirk Cousins leading an offense that has a few dangerous playmakers, the Vikings might have the most well-rounded team in all of football.

Every NFC North team is a playoff contender

A few hours after Minnesota won, the Green Bay Packers defeated the Chicago Bears in Sunday’s best game. There are reasons for both teams to have a positive outlook on the season following a crazy “Sunday Night Football” matchup.

It looked like Green Bay’s season was over when Aaron Rodgers left the game with a leg injury and the Packers trailed the Bears 17-0 at halftime. The quarterback was unstoppable when he returned in the second half and threw three fourth-quarter touchdowns to lead his team to a 24-23 victory. Rodgers had a 130.7 passer rating while banged up and playing against a tough defense, proving that—as long as he’s healthy—he alone makes the Packers legitimate Super Bowl contenders.

As disappointing as Sunday’s loss was for Chicago, it showed that this is a different team than the one that went 5-11 a year ago. Mitchell Trubisky made some big plays in Matt Nagy’s offense, and Khalil Mack’s impact was immediately felt as he recorded a sack and returned an interception for a touchdown. The Bears could be better than the Detroit Lions, who have had two straight winning seasons, making them part of arguably the NFL’s best division.