Welcome to the first of our 2018 Vikings grades. We'll start with the defensive line, which accounted for 34.5 of the Vikings' 50 sacks this season (third in the NFL). The blue-chip defensive line was also a driving force for the NFL's best touchdown-to-field goal ratio (0.85), according to Football Outsiders, fronting goal-line stands against San Francisco and Detroit.

Grades are based on a 1-to-5 scale, with '5' marking excellence, '4' for above-average, '3' for average, '2' for below-average and '1' for failure to perform. Players that did not accrue a season (weren't on the active roster for at least six weeks) or played in three games or fewer are not graded. Below are individual grades, based on game and practice observations, weekly film reviews and interviews with coaches, for 13 defensive linemen who finished the season on the Vikings' active roster, injured reserve or practice squad. Unofficial NFL stats, such as QB pressures, missed tackles and targeted passes, are compiled by ProFootballFocus.com.

DE Danielle Hunter (4.5) — Immediately rewarded the Vikings' trust with a career-best season after signing a five-year, $72 million contract extension in June. Hunter, 24, would've banked even more in free agency this spring had he not signed the contract. But the former third-round pick has expressed gratitude to the Vikings coaching staff for seeing his talent and helping mold him into a future perennial all-star pick, hence his willingness to sign the contract. Led the Vikings defensive line with 877 snaps [84.4%]. Earned his first Pro Bowl bid and was named second-team All-Pro. Finished with a career-high 14.5 sacks, earning a $500,000 escalator to next year's salary for eclipsing 13 sacks. He missed another half million by a 1/2 sack. One of the NFL's most complete edge rushers, Hunter was just one of four to rank top 10 in both total quarterback pressures (67 sacks/hits/hurries, 7th) and run stops (26 stops, 7th). Only J.J. Watt, Cam Jordan and Trey Flowers did the same this season. Hunter's 21 tackles for losses ranked second in the NFL behind L.A.'s Aaron Donald. Returned a fumble 32 yards for a touchdown and earned NFC Defensive Player of the Week honors for his 3.5 sacks in the Week 9 win against the Lions. Should be a NFL Defensive Player of the Year candidate if not for Donald's historically great season. One of five Vikings to play over 1,000 snaps, including his 146 on special teams to lead all Vikings starters. Flagged once for defensive holding. Missed six tackles.

Read here about Danielle Hunter's path to NFL stardom.

DT Sheldon Richardson (4.0) — Also didn't conjure up any buyer's remorse for the Vikings after signing a one-year, $8 million deal in free agency. Richardson said he hadn't heard from the Vikings about an extension through the season, but he's likely to get an offer before free agency opens March 13. Played 718 snaps [69.1%], second on the defensive line. Didn't quite return to his disruptive peak of the 2014 and 2015 seasons in New York, but Richardson was reliably disruptive if short of spectacular. He's a premiere athlete with relentless effort, evident when he chased down a screen while up 20 points in New York. Sprinted out of the gate with a gem in Week 1, forcing a season-high seven pressures (sack, three hits and three hurries) against San Francisco's Jimmy Garoppolo and a $20,054 fine for his roughing penalty. Spearheaded the final play of a goal-line stand, forcing initial hit that led to Alfred Morris' fumble at the 1-yard line. Had another strong pass rushing game in Week 2 at Green Bay, but didn't have a sack again until Week 9 against the Lions. His 4.5 sacks were his most in three seasons. Fell 1.5 sacks short of a $666,667 incentive. Turned 28 in November. Played through hip and shoulder injuries. Penalized four times, including two roughing calls. Missed four tackles. Below, Richardson's speed off the ball interrupts this stretch run by the Bears, splitting the center and guard to stall Tarik Cohen.

https://blog-media.startribune.com/access-vikings/wp-content/uploads/2019/01/08095503/Media1.mp4Richardson talks his recovery from a 'self-inflicted' downfall.

NT Linval Joseph (3.5) — Played 669 snaps [64.4%]. Showed off the jets when he snagged a Carson Wentz fumble and ran 64 yards for a touchdown in Philadelphia. Remains an upper-echelon run stopper with power and results in 23 run stops (14th) this season, down from 31 last year. He wasn't as disruptive as a pass rusher whether by design to free others or by turning 30 years old in October. Forced 18 QB pressures with one sack, down from 30 pressures the previous season. Missed his first game since 2015, against the Jets, due to a knee injury. Played through an ankle injury. Penalized four times, including three terribly timed: a third-down lowering of the helmet to revive Buffalo's opening scoring drive, an illegal hands to the face on fourth down in Seattle and the same in the red zone vs. Detroit. Joseph turned around and led the goal-line stand with an assist on a run stop, leading to two failed Lions pass plays and a field goal in the Week 9 win. The Vikings' run defense, with Joseph as its anchor, stumbled in stretches, allowing 148 rushing yards or more in four of the last six games. Even when Joseph had four run stops in Seattle, the Seahawks had 214 rushing yards. Joseph missed a tackle on Russell Wilson that led to a 10-yard scramble in that game. Missed three tackles all season. Salary rises to $8.9 million next season, when he'll turn 31, with none guaranteed.

DE Everson Griffen (3.0) — For the first time in 125 NFL games, Griffen had his first multi-game absence. This was to medically address his mental health after police were called to a downtown hotel with allegations he threatened employees. Griffen was not arrested, but that and other incidents on Sept. 22 led to a five-week absence from the team. He returned Week 8 against the Saints and was quickly returned his role as a full-time starter. Played 584 snaps [56.2%]. Regained some ground, but didn't have the same elite burst against the run or pass. Opponents had some success running to Griffen's edge, which was new. Had 5.5 sacks, his lowest since becoming a starter. Forced 28 QB pressures, down from 61 last season. Penalized four times. Missed four tackles. Could be a target for a contract restructure or cut as Griffen's $10.9 million salary is not guaranteed next season. Turned 31 years old last month.

DE Stephen Weatherly (3.0) — The former seventh-round pick made an impressive leap in his third NFL season. Started six games in Griffen's absence and had 15 QB pressures, including two sacks and two hits, in that span. Looked to have more speed rushing the edge, perhaps due to his comfort in the system and NFL. Played 523 snaps [50.3%], earning the primary backup job. Hit Carson Wentz in Week 5, causing the fumble that led to Joseph's touchdown run. Grew into a stout run defender, using his hands to win early, shed blocks and find the ball. Had 10 run stops in six starts. Started pass rushing from defensive tackle on third downs at the end of the season. Penalized three times, including a third-down roughing on Mitchell Trubisky to revive a Bears touchdown drive in the Week 17 loss. Second on D-line with 7.5 tackles for losses. But he missed six tackles. Entering a contract year in 2019 and is eligible for an extension this summer. Turns 25 in March.

DT Tom Johnson (2.5) — Re-signed with the Vikings before Week 3 after the Seahawks released him in a cost-cutting move following only one game. Played 342 snaps [32.9%], almost exclusively as a pass rusher. Still had some slippery moves at age 34 with his most sacks (4.5) in three years. Had a monster game in the Week 9 win against the Lions with 2.5 sacks and two stops. Penalized once. Pending free agent. Could be unlikely to return given his age and Vikings' need to develop younger interior options.

DT Jaleel Johnson (2.0) — Earned a role in the rotation after he was forced to redshirt in 2017 due to his low weight. Played 261 snaps [25.1%]. Forced a fumble when he and Xavier Rhodes sandwiched Tarik Cohen during the Week 11 loss in Chicago. Played mostly as Joseph's backup at nose tackle and showed plenty of room for growth. Had just three run stops. Had 13 combined tackles and did not miss one. Coaches noted better consistency, and less recklessness, as the season progressed. Penalized once.

DL Jalyn Holmes (N/A) — Drafted in the fourth round (102nd overall) out of Ohio State, Holmes wasn't active until Griffen and Bower were gone by Week 5. Played sparingly in three straight games, netting a sack in New York. Coaches envisioned Holmes as a defensive tackle, where he worked all summer, but he moved back to defensive end due to depth problems. Played 58 snaps [5.6%].

DE Tashawn Bower (N/A) — Bower's second NFL season started with opportunity, but ended on the inactives list. Played 53 snaps [5.1%], including 22 against the Bills in Week 3. Bower suffered an ankle injury the following week against the Rams. He was active just two weeks the rest of the season.

DE Ade Aruna (N/A) — Drafted in the sixth round (218th overall) out of Tulane, Aruna tore his ACL in a preseason game against the Jaguars. He'll turn 25 in April with a lot of ground to cover.

DL Ifeadi Odenigbo (N/A) — Returned to the Vikings practice squad Oct. 30 after the former draft pick was waived by the Browns. Played both defensive tackle and defensive end, impressing in the preseason at end, before he was cut by the Vikings. One of 10 practice squad players to sign a futures contract on Jan. 2.

DE Hercules Mata'afa (N/A) — Signed as an undrafted free agent out of Washington State. Mata'afa tried his hand at linebacker last spring, but moved back to defensive end. Tore his ACL during a June practice, ending his rookie season before it really started.

DT Curtis Cothran (N/A) — Signed as an undrafted free agent for $25,000 guaranteed out of Penn State. Rejoined the practice squad Oct. 27 after he was waived days earlier to make room for tackle depth. One of 10 practice squad players to sign a futures contract on Jan. 2.