Kirk Cousins will almost certainly play for a new team in 2018. (Toni L. Sandys/The Washington Post)

The Kirk Cousins era is over in Washington. The 29-year-old quarterback will all but certainly enter free agency after the Redskins acquired quarterback Alex Smith from the Kansas City Chiefs Tuesday night for a third-round pick and cornerback Kendall Fuller. He ends his six-year run with the franchise, three years as a starter, with the fourth-most passing yards (16,206) and sixth-most touchdowns (99) in team history.

With Smith off the market and Drew Brees likely staying with the New Orleans Saints, Cousins will be the only high-end passer available in free agency in March, and the only upper-tier quarterback in recent memory to reach the free agent market while still in his prime. Cousins is already the only quarterback ever to be saddled with the franchise tag in back-to-back seasons and figures to ink the biggest contract in NFL history.

To determine where he fits best, I am going to use a weighted three-year average of team ratings produced by the game charters at Pro Football Focus, with the most recent season, 2017, getting the most weight. Specifically, I am going to look at a team’s overall passing support — their receiving corps and pass-blocking ability — and run support. I will also look at the potential suitor’s defense since that, too, can play a big role in how successful a quarterback can be. Then, these opportunities will be assigned an overall letter grade, with better grades indicating more-attractive options.

With that in mind, here are the seven best landing spots for Cousins in 2018 among teams having both a need and salary cap resources to add him to the roster.

Minnesota Vikings

Grade: A
Salary cap space in 2018: $52.5 million

The Vikings are going from having three quarterbacks to having none — Case Keenum, Teddy Bridgewater and Sam Bradford are all set to become free agents in March. None are attractive as a long-term option, making it a nice fit for a franchise-caliber passer like Cousins.

They do have a very-talented group of pass-catchers featuring Adam Thielen, Stefon Diggs and tight end Kyle Rudolph.

Rudolph caught eight passes for touchdowns in 2017, the most for him since 2012, and led the team with 16 red-zone targets. Thielen and Diggs were the 10th and 11th best wideouts last season per PFF with Thielen producing 2.1 yards per route run from the slot, the second-best mark among slot receivers.

The Vikings also have a suffocating defense, ranked No. 2 overall behind Jacksonville in 2017 per Football Outsiders’ defense-adjusted value over average, which measures a team’s efficiency by comparing success on every single play to a league average based on situation and opponent.

And lastly, Minnesota has the sixth-most cap space next season.

Jacksonville Jaguars

Grade: B+
Salary cap space in 2018: $16.5 million ($35.4 million if they cut Blake Bortles)

Cousins said on Pro Football Talk Live it isn’t only about the money.

“Is money a part of it? Sure. Is it the only thing? No,” Cousins explained. “It is about winning, and that’s what I want more than anything, so I’m going to be willing to make sacrifices or do what has to be done to make sure I’m in the best possible position to win, and that’s what the focus is going to be.”

The Jaguars reached the AFC championship game in 2017 with Blake Bortles thanks in large part to a historically good defense. Bortles is under contract for 2018, but that money is guaranteed for injury only. If the team wanted to, it could move on from him with no cap hit if the Jags decide to take that route before June. Replacing Bortles with Cousins could elevate the Jags even further in terms of being a Super Bowl contender.

A team’s net passer rating, dubbed the “Mother of All Stats” during the 2012 Pro Football Researchers Association biennial meeting, has been a good litmus test for Super Bowl-caliber teams. Since 2002, 22 of the past 30 Super Bowl participants had a passer-rating differential among the top five in the league, including 10 of the past 15 winners.

If you substitute Cousins’s performance for Bortles in 2017, Jacksonville’s net passer would jump from 15.9, seventh, to 25.4, second, overall.

Buffalo Bills

Grade: B+
Salary cap space in 2018: $29.4 million

The Bills have one of the best offensive lines in the NFL, having allowed 124 total sacks, hits and hurries in 2017. Only the New Orleans Saints’ pass-blocking unit allowed fewer pressures last season. Two starters on the line, center Eric Wood and right guard Vladimir Ducasse, allowed just one sack each all season, though Wood may retire.

Cousins showed this season he doesn’t need an all-star cast to throw to, and receivers Kelvin Benjamin and rookie Zay Jones plus tight end Clay Charles form a decent nucleus. Benjamin averaged 1.7 yards per route run in 2017 for Buffalo with Tyrod Taylor under center and would give Cousins a 6-foot-5 red-zone target he’s never had in Washington.

There’s also LeSean McCoy in the backfield keeping opponents honest. McCoy rushed for 1,138 yards and six touchdowns last season and caught 59 of 77 targets for 448 yards and two more touchdowns. Cousins’s passer rating when targeting running backs was 106.3 from 2015 to 2017, the fourth-highest among quarterbacks over that span.

Unfortunately, the math might not work. According to Mike Rodak of ESPN, Buffalo is not expected to be part of the bidding war that could make Cousins one of the highest-paid players in the NFL.

Cleveland Browns

Grade: B+
Salary cap space in 2018: $109.6 million

The Browns enter the 2017 offseason with the second-most effective cap space in the NFL at about $109 million, more than enough to pay Cousins and upgrade the roster around him. Cleveland also has the No. 1 and No. 4 pick in the 2018 draft.

Cleveland’s offensive line was ranked fourth overall by PFF in 2017 and starters Joe Thomas, Shon Coleman, Spencer Drango, JC Tretter and Joel Bitonio are all signed through 2018 and beyond, as are backups Zach Banner, Geoff Gray, Joseph Cheek and Victor Salako. Thomas, the team’s left tackle since 2007, went down with a season-ending injury in October and could retire, which opens a huge hole. But with the team’s cap space and draft picks, the line likely won’t be a disaster in 2018.

Keeping Cousins clean in the pocket has the obvious benefit of better production: His passer rating dropped from 109.4 to 70.6 under pressure over the past three seasons.

Wideout Josh Gordon was reinstated by the league after a two-year absence and led the team in yards per route run (2.0) last season. He ranked 15th overall out of 93 receivers lining up for at least 25 percent of the team’s offensive snaps.

The Browns defense is also coming together: They stuffed a league-high 30 percent of rushers at or behind the line of scrimmage.

Denver Broncos

Grade: C+
Salary cap space in 2018: $26.8 million

It’s hard to know how good Denver’s offense can be because they have had terrible underwhelming quarterbacks running the offense. Trevor Siemian posted the worst Total Quarterback Rating as a starter in 2017, with his 27.7 QBR suggesting his team would be expected to win about 28 percent of the time given that level of performance. Paxton Lynch was even worse with a 22.8 QBR in two starts last season. Brock Osweiler was the best of the bunch with a 47.2 QBR.

The Broncos do have two solid, albeit aging, receivers in Demaryius Thomas and Emmanuel Sanders — both under contract until 2020 — and it is possible Cousins could get the best out of them since Peyton Manning left in 2015.

Arizona Cardinals

Grade: C+
Salary cap space in 2018: $22.7 million after Carson Palmer’s retirement. ($33.7 million if Larry Fitzgerald also retires)

Quarterback Carson Palmer played in just seven games in 2017 and retired in January. The franchise faces a real possibility that receiver Larry Fitzgerald will also choose to retire, leaving new head Coach Steve Wilks — Bruce Arians  retired in January as well — to figure out how to make the most out of this roster.

Arizona should see do-it-all running back David Johnson return in 2018. Johnson dislocated his left wrist in the Cardinals’ season opener and was out for the season. In 2016 he led the league in yards from scrimmage (2,118) and total touchdowns (20).

The offensive line is an issue: They allowed 217 total sacks, hits and hurries last year, second only to the Houston Texans (252).

New York Jets

Grade: C-
Salary cap space in 2018: $72.6 million

The Jets have a porous offensive line and allowed a sack rate of 8.6 percent after adjusting for down, distance and opponents according to Football Outsiders, making them the sixth-worst unit in football last season. Pro Football Focus was equally unimpressed and also had them as the sixth worst pass-blocking unit.

And who would Cousins throw to? The team’s most-targeted receiver, second-year pro Robby Anderson was ranked 37th by PFF for his 2017 performance, and journeyman Jermaine Kearse was rated only slightly better at No. 36. The good news is Anderson managed to get an average of 3.4 yards of separation between him and his defender last year, the ninth-best mark overall, which could help him improve on his already robust 4.3 yards after contact per catch should he get a better quarterback in 2018.

The team has enough money to improve the roster, almost $73 million in cap space next season. They also hold the No. 6 pick in the 2018 NFL draft, with most mocks projecting them to select Wyoming quarterback Josh Allen in that slot.

Read more:

Kirk Cousins’s tenure in Washington comes to an unofficial end

Kirk Cousins responds to ‘special’ assessments from Scot McCloughan, Mike Shanahan

Roger Goodell’s opinion of Redskins’ name unchanged after Chief Wahoo decision

Doug Williams’s Super Bowl win 30 years ago changed the game for black quarterbacks