EAGAN, Minn. — Much like the Vikings season itself, Minnesota's offense also endured ups and down in 2021.

There were plenty of highs, including five games of at least 400 yards of offense and at least 30 points.

But there were also some valleys, too, as Minnesota produced three games with 255 or fewer yards and 17 or fewer points.

On the whole, the offense finished a little better than middle-of-the-pack in some key statistical areas.

Minnesota ranked 11th in points per game (25.0) and 12th overall in both yards per game (362.8) and yards per play (5.70).

Here's a deeper look at where the Vikings offense excelled, and fell short, in 2021.

3 strong offensive stats in 2021:

1. Jefferson on intermediate routes

Let's be honest, Jefferson excelled all over the field in 2021.

He set career bests in catches (108), yards (1,616) and touchdowns (10) in his second season, and just missed surpassing Randy Moss' single-season record of 1,632 yards that was set in 2003.

But the 22-year-old was perhaps the NFL's best wide receiver on intermediate targets, which are classified as 10-19 yards beyond the line of scrimmage.

According to analytics site Pro Football Focus, he posted a 99.9 grade on such targets, which tied with San Francisco's Brandon Aiyuk for the best mark in the league.

Jefferson was targeted 61 times in the intermediate area, which led the league, and he also led the NFL with 40 catches and 726 yards in that particular depth of target. Jefferson's 193 yards after the catch on intermediate throws also led the league.

The Vikings second-year wide receiver was once again one of the league's top pass catchers in 2021 and put up strong numbers on every inch of the field.

But he was among the best of the best on intermediate targets.

2. O'Neill's pass blocking

Brian O'Neill signed a multiyear contract extension just before the start of the 2021 season and promptly backed that up by cementing himself as one of the league's top right tackles.

O'Neill wasn't name to either All-Pro Team by The Associated Press, but he received three total votes, a sign that people around the league have taken notice of his play.

His pass blocking was likely a key reason for that increased national attention. According to PFF, O'Neill ranked 13th with a pass-blocking grade of 78.2 among all tackles (left and right) who played at least 800 offensive snaps.

O'Neill, who led the Vikings in pass-blocking grades and was also the team's highest-graded linemen at 73.7, allowed just one sack on the season (and it didn't occur until Week 18).

With a new contract set to start in 2022, O'Neill isn't going anywhere, and the captain will be counted upon as a key team leader as the Vikings hire a new general manager and head coach.

3. Team interception rate

Kirk Cousins wasn't the only quarterback to see the field this season, as Sean Mannion and Kellen Mond also took snaps (albeit on a limited sample size for each).

Still, the three of them combined throw just seven interceptions on 604 total pass attempts, as that interception rate of 1.16-percent led all NFL teams.

Cousins played 1,087 snaps and threw all seven interceptions. Mannion and Mond combined for 54 snaps and did not throw a pick.

But the Vikings quarterbacks excelled at not throwing the ball to the other team, as the seven total picks tied for the fewest among all teams.

Green Bay (1.18-percent interception rate) and Seattle (1.41-percent interception rate) were teams that also threw seven total interceptions. Both of those teams had multiple starting quarterbacks in 2021, as well.

2 stats that need to improve in 2022:

1. Third-down percentage

The Vikings simply couldn't stay on the field enough in 2021.

And Minnesota was downright bad on third downs.

The Vikings converted on just 36.4 percent of their third-down tries in 2021, which ranked 26th overall in the league. Minnesota moved the chains just 83 times on 228 total tries.

(Perhaps it's not a surprise that the Vikings also tied with the Texans with 53 total three-and-outs, which was the most among all NFL teams and could have been its own stat to include here).

But an inability to consistently convert on third downs routinely hampered the offense (and team overall).

And it played a key reason in why Minnesota missed the playoffs for the second straight season, as there is a strong correlation between offensive third-down success and making the postseason.

Of the 14 teams that qualified for the postseason, a dozen finished in the top half of the league in third-down success. (The other two teams — Pittsburgh and Las Vegas — also finished ahead of Minnesota).

And there's an even stronger case for this stat at the top of the league, as 10 of the top 11 offenses in terms of third-down conversions made the playoffs, and six of those teams will play in the Divisional Round.

2. Per-play success rate

That's a bit of a generic term, so here's an explanation on it.

Besides the well-known stats that have been around for a while (points per game, yards per game, yards per play, etc.), two stats rising in both popularity and objectiveness are Expected Points (EP) and Expected Points Added (EPA).

This article offers a great explanation of what both are, and breaks down how it is analyzed. Here is a line that tries to simplify it:

Expected Points is based off the notion that not all yards gained in football are of equal value. For example, a 5-yard gain on third-and-3 increases a team's chances of scoring much more than the same 5-yard gain on third-and-10. While both situations would reflect a gain of five yards in a traditional box score, the first would result in a first down and continue the drive, while the other would likely force the team to punt on fourth down. Expected Points attempts to quantify this difference in value by relating each play to how much it increases (or decreases) a team's chances of scoring.

Both EP and EPA are also used to calculate a team's offensive success rate on a per play basis, which is where the headline above comes into play.

Based on these numbers, the Vikings were successful on just 41.6-percent of their offensive plays, which ranked 25th overall in the league. Minnesota's EPA per play, which can also be found in that link, ranked 17th.

No matter who you look at it, the Vikings offense had some strong moments, but were generally average at best.

Those who followed the team closely likely aren't surprised by that, as it felt as if the unit was too stop-and-go for most of the season.

But the above data highlight that when you really dive into the numbers, the Vikings weren't among the upper echelon of offenses across the league.