Minnesota Vikings head coach Mike Zimmer called it the 64-thousand-dollar question, others around the NFL—now specifically in Denver—would likely say it’s the 36-million-dollar question.

Who in the world is Case Keenum?

On a personal level, Casey Austin Keenum is a 30-year old gunslinger from the small town of Brownwood, Texas standing an inch above six feet and married to fellow-Texan Kimberly Caddell.

But the burning answer that everyone wants to know is—is Case Keenum the journeyman backup quarterback he was the first five years of his career, or is he the MVP-caliber quarterback he was last year with the Minnesota Vikings?

This was the question the Vikings asked themselves over and over and over again this offseason.

“Is Case Keenum the quarterback he was last year or who he was three years ago,” Zimmer openly questioned at the NFL Combine two weeks before free agency started. “You’ve got to go on your gut; you’ve got to go on what you see, you’ve got to go on his heart. Case has a big heart. He’s a great competitor. He studies his rear end off. He works an unbelievable amount of hours. The question is exactly what you’re asking: Is he this guy?”

Even with the compliments from his former head coach, it would appear Zimmer, and the Vikings eventually determined he was the Keenum of old.

The Broncos, however, unequivocally believed the latter. And they laid down $36 million over a two-year contract to back that up.

After rewriting the college record books during his time at the University of Houston—holding the record for most completions (1,546), passing yards (19,217) and passing touchdowns (155) to this day—Keenum went undrafted.

Yes, not one team took a chance on the quarterback that statistically had the best college career a quarterback has ever had. That was until the Houston Texans, led by now-Broncos-top-executive Gary Kubiak, offered him a spot as an undrafted free agent. After spending his first year on the practice squad, Keenum was elevated from the third-string quarterback to the starter midway through the season.

Unfortunately for Keenum, his first opportunity to start came during the Texans’ 14-game losing streak as he contributed to eight of those losses. While the quarterback himself played admirably—nine touchdowns to six interceptions—especially considering it was his first NFL experience, Kubiak was fired, and massive change swept over the organization simply making Case an 0-8 undrafted starter from a small school.

The following season, in 2014, Keenum bounced back and forth between the then-St. Louis Rams and the Texans—making, and winning, two spot starts—before finding his home for the next two seasons with the Rams, who would move to Los Angeles in the middle of his stint.

In the first year, Keenum began the season as Nick Foles backup before taking over for six games, where he went 3-2 and had four touchdowns to one interception, finishing the season with an 87.7 passer rating. The Following year, the Rams were so impressed with Keenum they placed a rare first-round tender on him and made him their starter entering the season.

After a disappointing nine-game stretch—where he had nine touchdowns to 11 interceptions—Keenum was benched for the first-overall pick in the draft, Jared Goff.

This is the Case Keenum before his marvelous year with the Vikings, the one that people now point to in fear as the journeyman backup quarterback. In a total of 26 games, he posted a 9-15 record as a starter, had 24 touchdowns to 20 interceptions and averaged just over 200 passing yards per game.

The only season he was on a winning team was his 2014 two-game stint with the Texans in which he took a 7-7 team and led them to a 9-7 record. The only time he was given the starting job entering the season was for the Rams team that previously had the No. 1 overall pick in the draft.

On the surface, his resume during these five years doesn’t inspire confidence that he’s worth $18 million per year, as Denver is paying him, but a deeper look proves he was never set up for success or put in a half-way decent situation.

The “other” Case Keenum took center stage last season in Minnesota. As an insurance policy to starter Sam Bradford and a recovering Teddy Bridgewater, the Vikings signed Keenum to a one-year, $2 million deal to continue his journeyman career.

However, after Bradford couldn’t play after just the first game of the season due to injury, Keenum started 14 of the team’s remaining 15 games, going 11-3 and leading Minnesota to the NFC Championship game.

“Case Keenum came in, led our football team, did a phenomenal job,” Vikings’ General Manager Rick Spielman said at the combine. “He has a knack for making plays. He made a lot of big plays for us because of not only his smarts, his leadership, but his mobility as well.”

During the incredible run, Keenum’s 67.6 completion percentage, and 71.3 quarterback rating were the second-best in the entire NFL. He also added 22 touchdowns to seven interceptions for a passer rating of 98.3

In the only season where Keenum played more than 10 games in a season, he shined.

In today’s NFL, this type of season is unquestionably worth at least $18 million per year.

Yet at the end of the day, the Vikings ultimately decided the Case Keenum they knew wasn’t the real Case Keenum, instead opting to pay Kirk Cousins $10 million per season for more years and significantly more guaranteed money.

The question of “who is Case Keenum” is still very much an uncertainty to the minds of many. Not to John Elway and the Broncos, though. They hope to cash in on the Vikings, and the rest of the league’s, uncertainties.