Lists. We like our lists, don't we? We read them. We write them. In sports, we argue about them like people who used to argue about things that were, you know, important.

Let's go back in time. Four months ago. It's August. NFL teams had five months to add new players. And you know what that means in this biz, right?

Lists!

Best offseason acquisition!? Duh! Brandon Marshall, you idiot! He'll put the Giants over the top, baby. And it only cost them $11 million over two years!

Worst offseason acquisition!? Are you serious? Riley Reiff, you moron! Five years, $58.8 million? The Lions didn't want him at right tackle, let alone left tackle. And he's starting camp with a back injury! Bring me Spielman's head on a stick!

Then there's Case Keenum.

Poor Case didn't register a ripple either way when he signed. He was paid $2 million to spend six games between Sam Bradford's knee and Teddy Bridgewater's white horse.

Case who? Sam's fine. His knees survived the Swinging Gate Offense of '16, didn't they? And, besides, Teddy B will be off PUP after six games.

(Fade to present day …)

The Vikings are 11-3 with Keenum playing all but six quarters. He has not only become the NFL's best offseason acquisition of 2017, I'll say he's the best offseason bargain the NFL has seen since April 25, 1972.

On that day, Dolphins coach Don Shula paid the $100 waiver claim fee to acquire a 38-year-old QB named Earl Morrall. Shula had coached Morrall in Baltimore, so it was a nice, comfortable Plan B behind Bob Griese.

In Week 5, Griese got hurt. Morrall stepped in, finished off that victory and went 11-0. He started the final nine regular-season games and two playoff games before Griese returned to cap off the 17-0 season with a victory over Washington in Super Bowl VII.

Like Morrall, Keenum is part of a good team. Unlike Morrall, Keenum plays in an age when the quarterback can't be hidden.

In 1972, Morrall was able to play nine-plus regular-season games while throwing only 150 passes. His 91.0 passer rating led the league that year. Today, it would rank 16th, a smidge ahead of Blake Bortles.

Morrall beat the Browns and Steelers in the playoffs while throwing 24 passes. Combined. Griese threw 11 passes in Super Bowl VII.

Keenum has thrown 427 passes with 20 TDs and seven interceptions. He is not the only reason the Vikings won the NFC North. But he could have been the most significant reason if they hadn't.

If you don't believe that, face north, look 250 miles to your right and wave goodbye to the Packers' season.

If the season ended today, eight of 12 playoff spots would go to teams that didn't make the playoffs a year ago. The Eagles went from worst to first in the NFC East, while the Rams and Jaguars are in position to do the same in their respective divisions.

So the Vikings weren't alone in making some shrewd offseason acquisitions.

The Eagles signed Alshon Jeffery, who has nine receiving touchdowns. The Rams changed overnight when they signed left tackle Andrew Whitworth.

The Saints struck gold in the first round of the draft (Marshon Lattimore) and platinum in the third round (Alvin Kamara). The Panthers added quality via something new (Christian McCaffrey) and something vintage (Julius Peppers).

The Patriots swapped a first-round pick for something better (Brandin Cooks). The Steelers gave Ben Roethlisberger yet another weapon (JuJu Smith-Schuster), while Kansas City beefed up its offense before the season (Kareem Hunt) and its special teams during the season (Harrison Butker).

And Jacksonville won the sheer volume category by adding its leader in sacks (Calais Campbell), interceptions (A.J. Bouye), rushing (Leonard Fournette) and competent blocking (left tackle Cam Robinson).

I suppose if Philly's Nick Foles beats Keenum in the NFC title game and wins the Super Bowl in Minneapolis, we'll have to revisit this list.

But, right now, it's hard to imagine anyone outranking Keenum, the guy who didn't register a ripple either way just four months ago.