Case Keenum was excellent for Minnesota last year. He was a disaster in L.A. the season before with the Rams. Which fella turns up for the Broncos on Sunday is anybody’s guess.

Keenum didn’t just drastically improve his output with the Vikings; he changed how he played.

In his final year with the Rams, he left a bunch of throws on the field. He never felt comfortable in an offense that stymied his best instincts. Keenum is a rhythm thrower. He wants to play within the structure of an offense: hit the back foot and get the ball out:

He doesn’t do well when asked to play off-script.

Minnesota was the perfect cauldron for him to blossom. He was surrounded by a bunch of talent at the skill spots and an offensive coordinator (Pat Shurmur, now the Giants head coach) who understood his quarterbacks’ strengths and weaknesses.

Keenum made smart decisions. And he made them fast. He has always been a quick decision-maker, but he hasn’t always been on-point. In his lone year in Los Angeles he threw 9 touchdowns to 11 interceptions. He forced throws to spots where he shouldn’t. Driving inaccurate throws over the middle-of-the-field became his favorite pastime, often born out of frustration, as receivers failed to uncover.

The Vikings made things easier. The ball had to come out quick. The team’s offensive line stunk. Keenum was pressured on 36% of his dropbacks (per ProFootballFocus), more than any other quarterback in the league. Getting the ball out in a hurry became the only way for the offense to stay on schedule. Quick passes became an extension of the run-game, particularly once rookie running back Dalvin Cook went down.

Throwing to a pair of great receivers helped, too. Keenum spent the year launching balls to Adam Thielen and Stefon Diggs, a pair of receivers dominant individually, and perhaps the very best two-man tandem in the game.

Guys were always streaking open. Shurmur helped with some creative play-designs. The Vikings moved a bunch pre-snap, serving as coverage revealers for the QB. Post-snap, Shurmur called a battery of man-beater concepts, designed to spring Diggs or Thielen free against sticky coverage.

Keenum, a career journeyman, who was pressured more than any time in his career, had his best season to date. His adjusted yards per attempt ballooned from 5.9 to 7.6; his interception percentage tumbled from 3.4% to 1.5%. He became more efficient, while continuing to do what he loves best: take deep shots. Keenum was the third-most accurate thrower in the league on throws over 20-yards in 2017, per PFF.

The numbers match the tape. Keenum took what a defense gave him, as coaches love to say. Sure, he was aggressive down the field, but it was a cautious aggression. More often, he was happy to flip the ball underneath and let his guys go create after the catch.

This new, improved Keenum still has flaws.

Oddly enough, Keenum has a better career passer-rating on throws delivered under 2.5 seconds than ones over that threshold. He doesn’t just want to play with rhythm and bounce. He needs to.

On quick-timing throws, he’s excellent. He does a nice job of quickly identifying coverages and how a route combination corresponds with the leverage of particular defenders. And he diagnoses it all rapidly. By the time he’s hit the back foot, he’s made his mind up and he’s eager to get rid of the ball. When everyone is on the same page, moving the ball can look effortless:

Above, watch how quick he identified man-coverage. As soon as he swiveled towards the line of scrimmage, he knew his guy was open through-play design: a comeback vs. bump-and-run should be easy yardage, as long as the throw is on point. It was.

Denver, like Minnesota, is using pre-snap movement to give Keenum the tells he craves:

Flashing a motion-man across the formation allowed Keenum to see it was man-coverage. Again, he was able to jump to his primary read. His receiver had a quick-out against off-coverage, more easy yards. Keenum put the ball in a spot where only his guy could make a play on the ball.

Keenum has become a safe thrower. He’s willing to punt the ball away and come back the next drive (ugh!). And he doesn’t panic under-pressure. So, Seattle needs to find a schematic way to bait him into mistakes.

Seattle will run its base scheme. We know this. They’re not going to get fancy with a whole bunch of movement. But without a dominant four-man rush, the team will need to introduce more blitz looks and more creative pressure packages.

As Matty Brown and I discussed in this piece, fire-zone packages look like the way forward in 2018. The key to fire-zone success is using the right design against a specific quarterback. One design does not fit all.

Keenum struggles on intermediate throws. His accuracy numbers between 10-20 yards sat behind such luminaries as Tom Savage, Trevor Siemian, and Blake Bortles in 2017. Intermediate throws require field awareness, anticipation, and touch, particularly on any in-breaking design. Not Keenum’s strong suit.

Keenum doesn’t like any movement at the second-level: linebackers starting at the LOS then dropping to the low-hole; ‘backers buzzing towards the sideline; safeties inverting their responsibilities; safeties running from the middle of the field to the flat; robber looks; linebackers sinking into coverage.

Keenum sees it all a beat too late. He struggled with the Rams’ slew of option routes. He couldn’t get on the same page as his receivers. Linebackers sinking into zone-coverage became a hazard:

All quarterbacks a have a thing – that idiosyncratic way they turn the ball over. I mean, there’s a reason trap coverages exist. Some consistently get caught trying to squeeze the ball between the safety and corner in cover-2. Others struggle with identifying spinning safeties. A whole bunch panic under pressure.

Keenum’s mental block back with the Rams was those dastardly dropping linebackers:

Above, Keenum failed to identify Thomas Davis. The Carolina Panthers linebacker peeled off a Rams tight end and sat in an underneath zone. Keenum hit him in the middle of his chest. Awful.

Things were different when he moved to Minnesota. Keenum worked touchdown, to sideline, to checkdown, avoiding the intermediate areas where he struggles. Inverted looks (corners and safeties flip flopping traditional responsibilities in coverage) became his next issue. So quick was he to spray the ball out-wide, he’d misread a corner peeling out of press coverage or a safety zooming towards the flat:

That’s a basic Cover-1 look with a Mike blitz. It’s a six-man rush. Washington drops one linebacker into the low-hole and maintains a single-deep safety. The rest of the DBs man-up: it’s banjo-coverage on one side of the field and man-to-man on the other.

Washington’s spinning safety caught Keenum by surprise. The safety climbed over the top of the in-breaking route from the boundary receiver, rather than scooting underneath. Typically that safety would plunge towards the line of scrimmage in case he needed to re-route the tight end on a vertical release. By the time Keenum realized the safety was buzzing towards the sideline, it was too late -- D.J. Swearinger had jumped the route.

A ton of Keenum’s interceptions in the past few years have come on tipped balls. Some are flat-out comical:

Yet most of the time, the same issue reading the second-level reared its ugly head: He forced balls over the middle; he misjudged the depth of a linebacker or safety; somebody got a hand on the ball and it shot in the air. This should make Ken Norton giddy:

Few teams in the league have the same level of sheer athleticism at linebacker and safety as the Seahawks. The base defense may be fairly vanilla, but when Norton is willing to roll out fire-zone packages, anybody and everybody can slide to different spots on the field comfortably (having K.J Wright available this week would have helped. But Shaquem Griffin is an excellent spot-dropper).

A bunch of moving parts at the second-level is Keenum’s worst nightmare.

The Seahawks made hay last year on slot-blitzes. They would fire Justin Coleman towards the backfield on man-blitzes and zone-pressures; there was no coverage or tendency tell. That bodes well for Sunday.

One of the team’s best designs was a zone-pressure out of mug — double A-Gap — look against Philadelphia:

The key here is not the blitz itself. It’s the corner bailing, linebacker dropping, and safety sliding. Tricking Keenum post-snap will be more important than the much-discussed and maligned pass-rush.

The Broncos are going to rely on quick-timing drops that demand Keenum to anticipate coverages. They’ll sprinkle in plenty of play-action to help the thing along. And a few shot plays will be dabbled in here and there.

But don’t expect the quarterback to take steep drops and survey the landscape. That’s not his game. Even when Minnesota took shot downfield last year, it was within the rhythm of the offense — a quick first or second read.

And it’s not like Keenum is working with the same artillery as last year. Demaryius Thomas remains a solid post-up, back shoulder threat. Emmanuel Sanders is still a slot receiving stud. Neither is on the same level as Adam Thielen or Stefon Diggs. There isn’t a starter-caliber tight end on the Broncos’ roster, either. And Keenum is once again working with an o-line that could prove to be a disaster.

All of that opens up opportunities for Seattle to bait the quarterback into mistakes. Keenum was fabulous in 2017, but his tendencies remain overt. He doesn’t have the playmakers (nor the play-caller) to bail him out of misreads this year. Fooling him just once could be the difference in Sunday’s game.