After they added the NFL’s biggest free agency prize and a Pro Bowl defensive tackle to a team that went 13-3 on its way to the NFC Championship Game a year ago, the Vikings head into their bye week already guaranteed to finish with fewer wins than they did in 2017.

They are 5-3-1 after their first nine games of the season, percentage points behind the upstart Chicago Bears for the NFC North lead before the two teams meet at Soldier Field a week from Sunday night. The fact the Vikings have won four of their past five games — and because the run came after their coaches took a hard look at how teams were scheming to beat the NFL’s top defense from a year ago — had General Manager Rick Spielman optimistic on Tuesday about the trajectory of the 2018 season.

“Every year is different. I know every year you want to go in and you want to win every game,” Spielman said in his bye week interview session with reporters on Tuesday. “A couple games, a ball bounce here and there and maybe it’d be a different outcome. But I know we’re 5-3-1 at this point and it’s what we do going forward here that will determine the success of the season.”

Tom Baker for Star Tribune
VideoVideo (03:09): Running back Latavius Murray knows the Vikings are dangerous, but believes there's always room for improvement when striving for perfection.

The Vikings were 1-2-1 after the first four games of the season, having given up 556 yards in a Thursday night loss to the Rams that prompted theories from around the country about whether the Vikings’ defense had been figured out. While coach Mike Zimmer publicly rejected those theories, he started in on a process of analyzing what teams were doing to beat the Vikings and devising ways for his defense to adapt.

During the Vikings’ first four games, opponents averaged 381.5 yards and 27.5 points per game against them; those numbers have dropped to 274.8 and 18.8 in the past five weeks.

“There’s a lot of smart people in this league, and in order to keep moving forward, you just can’t keep getting hit in the head with the same thing,” Spielman said. “A lot of the different adjustments he’s made, I think, has made a tremendous impact on how we’ve played over the last four or five weeks.”

Spielman still was flabbergasted Tuesday about the Vikings’ 27-6 loss to the Bills on Sept. 23, saying, “To be honest, the Buffalo game, that’s not the Minnesota Vikings that played that game.” As the Vikings defense regrouped after the game, though, Spielman praised the job offensive coordinator John DeFilippo and quarterback Kirk Cousins have done to assess their own progress in their first year working together.

“Kirk not only has done extremely well in how he’s performed, especially when he’s been getting pressured in the pocket, but you see some of the throws that he makes in games, those are some throws that are unique,” Spielman said. “There’s not a lot of people who can make those type of throws.

“But it’s also how he’s developed into a leader of this football team. I know I’ve sat in a couple quarterback meetings where they’re sitting in there going over the game, and just sitting there listening to him talk, and being critical of himself and how he can improve. He’s always looking to try and get better. It’s pretty fascinating to sit there and listen to him sitting there breaking down game tape, and how important this is to him.”

Tom Baker for Star Tribune
VideoVideo (03:37): Quarterback Kirk Cousins says he's pleased with the Vikings, despite some concerns at the start of the season about all of the changes that were being made.

The Vikings will return from their bye to a pivotal stretch of games that includes back-to-back Sunday night contests against the Bears and Packers before a trip to New England and a Monday night game at Seattle. Those games likely will determine the Vikings’ chances to win their third division title in four years, as well as where they stand in the NFC playoff field.

The five teams they’ve defeated have a combined winning percentage of just .342 this season, and the Vikings’ only two remaining games against teams that currently have a losing record come in their rematches with the Packers and Lions.

Their task after the bye week will be to take the improvements they made during the season’s second quarter and carry them on through its final acts.

“I certainly would have loved to have been better than 5-3-1, but I’m grateful we’re not 3-5-1, you know?” Cousins said. “You can look at it both ways. The point is, and I keep saying it, everything’s in front of us. We can talk about the past or where we are, but at the same time, when you have meaningful games to be played in November and December, let’s look forward and focus on that.”