One year ago, the Arizona Cardinals were excited to draft their quarterback of the future. This weekend, the Cardinals are excited to have drafted their quarterback of the future again. One year after selecting Josh Rosen with the 10th overall pick, Arizona signaled its desire to move on from its 2018 first-rounder by taking Kyler Murray with the first overall pick. And on Friday, the Cards sent Rosen to the Miami Dolphins for the 62nd overall selection and a 2020 fifth-rounder.

Once the Cardinals drafted Murray, Rosen was a sunk cost. There was little point in keeping him around. The Cardinals obviously think Murray is going to be a superstar, and I'm inclined to agree.

But I also wouldn't be so quick to shut the door on Rosen, even given how his stock has fallen over the course of the past 12 months. I think there's a strong case that Rosen still has plenty of upside, even after a difficult rookie season. The finances of this deal also make it a great opportunity for a rebuilding Dolphins team with little to lose. Miami might very well have found its quarterback of the future at the beginning of its rebuild.

Why you can throw out 2018

Every bit of information we have on a young quarterback matters. Some of it means more than the rest, of course, but the most valuable intel in figuring out whether a quarterback can play at the NFL level, naturally, is seeing him actually perform in the NFL. By anyone's definition, Rosen stunk across his 393 pass attempts last season. For some observers, that might be enough to write him off.

But I don't think that data means much. For one, Rosen was thrown in the deep end as part of a Cardinals offense that was a disaster for reasons outside of his control. Arizona fired offensive coordinator Mike McCoy after seven games and replaced him with first-time offensive coordinator Byron Leftwich. The coaching staff as a whole was uninspiring enough for Steve Wilks & Co. to lose their jobs after only one season in the desert. Rosen's struggles didn't help their cases, but it's hard to argue Rosen had great coaching.

More importantly, his offensive line was a disaster. Other rookie quarterbacks have started their careers behind porous offensive lines, of course, but not to this extreme. By the end of last season, the Cardinals had lost all five of their starting linemen to injuries. During the second half of 2018, the five linemen who took snaps most frequently protecting Rosen included a pair of rookies (third-rounder Mason Cole and seventh-rounder Korey Cunningham), a player signed off Minnesota's practice squad (Colby Gossett) and a pair of veterans who were cut by teams and almost immediately stepped off the street and into Arizona's starting lineup (Oday Aboushi and Joe Barksdale). It's one thing to have a relatively untalented line, but the Cardinals were starting guys who barely knew the playbook at times.

It's also important to mention that 393 pass attempts wouldn't solve the puzzle, even if Rosen had played well. As ESPN's Brian Burke pointed out in analyzing Jimmy Garoppolo, it takes about 1,000 pass attempts before we can be realistically confident about a quarterback's true level of ability. We probably know more about Rosen than we did about Garoppolo before he was traded to the 49ers, but the sort of challenging context Rosen grappled with in Arizona is the exact scenario that would render a small amount of data less meaningful.

Now, to be clear, I'm not saying that Rosen is secretly a superstar. Those 393 pass attempts might very well be an excellent representation of how he's going to perform in the future. The Packers signed Aaron Rodgers to a contract extension in 2008 after seven starts and 280 career pass attempts, and it turned out he was even better than the guy the Packers thought they had when the franchise put pen to paper.

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What I'm saying is that the 2018 data on Rosen is so flawed and limited as to render it mostly irrelevant in evaluating him as a possible NFL starting quarterback. We don't have enough information to reject the league's opinion of Rosen before September, which suggested he was a first-round pick and a viable quarterback prospect. It's possible that the Cardinals were the only team that thought Rosen was worthy of a first-round pick, but I'm skeptical he would have made it out of the first round -- or even out of the teens -- if Arizona hadn't drafted him at No. 10.

The most notable example of this phenomenon, of course, is Jared Goff. In his first year with the Rams, Goff averaged just 4.3 adjusted yards per attempt and posted a passer rating of 63.6 over a 205-pass sample. His offensive coordinator was Rob Boras, whose previous time as a coordinator had come at UNLV in 2001. Goff's primary targets were Kenny Britt, Tavon Austin, Lance Kendricks and Brian Quick, none of whom are still NFL starters. He had Rodger Saffold and Rob Havenstein along the offensive line, but the three other linemen to take the most snaps with Goff as a rookie were Tim Barnes, Andrew Donnal and Greg Robinson, all of whom have bounced around the league since 2016.

The Rams didn't trade Goff, but his context totally shifted. They hired a new coach in Sean McVay, signed Robert Woods, Andrew Whitworth and John Sullivan, drafted Cooper Kupp, and traded for Sammy Watkins before replacing him with Brandin Cooks. Since then, Goff has produced consecutive Pro Bowl seasons and looks like the guy the Rams expected when they drafted him with the first overall pick. There's no guarantee Rosen will flourish in the same way -- there's only one Sean McVay, as NFL teams have sadly found out -- but the Goff who was barely functional during his rookie season doesn't remotely resemble the passer who has broken out since. The Dolphins hope Rosen undergoes a similar awakening.

The value proposition

What makes trading for Rosen even more appealing is the fact he doesn't have to turn into Goff to return value. The Cardinals handed Rosen a four-year, $17.6 million contract that was fully guaranteed when the quarterback signed it last May, but $10.9 million of that deal was in a signing bonus the Cardinals paid at the time. The Cardinals also paid Rosen a base salary of $480,000. They ended up paying him $11.4 million for one season and will eat $14.4 million in dead money on their cap for 2019.

That's disappointing for the Cardinals, but it's great news for the Dolphins. Essentially, coach Brian Flores & Co. are acquiring Rosen on a three-year deal worth about $6.4 million, with the possibility of locking in a further option in 2023 at $17.6 million. Only the $6.4 million is guaranteed, and Rosen won't top a cap hit of $3 million until that possible option in 2023.

Rosen doesn't even need to turn into a starter to make that deal work. If the UCLA product is even a competent backup, he'll be a profitable asset for the Dolphins.

I went through each team and found that the quarterbacks they've signed or drafted to fill the backup roles are making an average of about $2.4 million per season in their current deals. Factor in a 6 percent average increase for the rise in the cap and they would be up to a total of $7.6 million over the next three years, about 19 percent more than what Rosen is in line to take home over that same timeframe. If Rosen can play like an average backup -- somewhere in the range of Matt Schaub or AJ McCarron -- his deal would be moderately profitable, albeit not worth the draft pick the Dolphins traded to acquire him.

Let's imagine a scenario in which Rosen is a borderline starter or an upper-echelon backup, like a quarterback in the ballpark of a Tyrod Taylor or a Ryan Fitzpatrick. Those are guys who organizations realistically expect could step in and keep their team afloat. They make a lot more than Rosen will, as their deals currently average $6.9 million per season. After building in the cap increase, you're looking at $22 million over the next three years, and Rosen is saving you $15.8 million over the next three years.

We can use ESPN's new draft projections to capture what we thought of Rosen before the 2018 season and get a sense of what value he might provide. I split the league's quarterbacks into five categories to essentially emulate where Rosen might fall, ranging from superstardom down to a player who isn't worth rostering, and then found what players in those tiers are making on their current contracts. I used ESPN's projection model to plug in the chances that Rosen would eventually fall into each of those tiers, which gives us an idea of how much Rosen's contract would be worth over the next three seasons:

Category Chances Annual

Salary 2019-2021 Vs. Rosen

Contract Surplus

Value Star 12.6% $23,612,299 $75,172,115 $68,932,727 $8,685,524 Starter 39.0% $14,565,955 $46,372,174 $40,132,786 $15,651,787 Borderline Starter 23.3% $6,923,988 $22,043,208 $15,803,820 $3,682,290 Backup 21.9% $2,441,908 $7,774,058 $1,534,670 $336,093 Unrosterable 3.2% $0 $0 -$6,239,388 -$199,660 Surplus Value $28,156,033

That's really impressive. Given our pre-draft estimates, Rosen's contract is worth more than $28 million in surplus value over the next three seasons without even considering the possibility of picking up his fifth-year option.

To put that in context, the Browns drafted Denzel Ward with the fourth pick of the 2018 draft and gave him $29.2 million over four years. The league's top cornerbacks -- the guys I would put in that star category -- are making an average of about $13.8 million per season on their deals. Factor in the 6 percent cap rise and a great corner would be in line to make about $60 million over the four years of Ward's deal. If Ward continues to emerge as a superstar, he'll be worth more than $31 million in surplus money over four years. Given the average range of Rosen's possible outcomes, his deal would seemingly be worth $28.1 million over three seasons.

I wouldn't trade Ward for Rosen, but I'm pointing this out to illustrate just how valuable the upside of getting a star quarterback making a little more than $2 million per year can be. Let's take a more conservative approach and cut the chances that Rosen is a star or a starter in half while splitting the remaining odds evenly across the three other less-exciting outcomes. In this scenario, Rosen has only a 25 percent chance of becoming either a starter or a star. How much would his contract be worth in surplus value?

Category Chances Annual

Salary 2019-2021 Vs. Rosen

Contract Surplus

Value Star 6.3% $23,612,299 $75,172,115 $68,932,727 $4,342,762 Starter 19.5% $14,565,955 $46,372,174 $40,132,786 $7,825,893 Borderline Starter 31.9% $6,923,988 $22,043,208 $15,803,820 $5,041,419 Backup 30.5% $2,441,908 $7,774,058 $1,534,670 $468,074 Unrosterable 11.8% $0 $0 -$6,239,388 -$736,248 Surplus Value $16,941,900

Even in a scenario in which Rosen tops out as a middling starter nearly three-quarters of the time, the final three years of his contract remain incredibly valuable. Remember that the Browns ate the $16 million remaining on Brock Osweiler's contract as part of a deal to take home a second-rounder. I'm not sure every team would value a second-round pick at that same level, but you can understand why the Dolphins sent a second-rounder to the Cardinals to acquire Rosen.

Why now?

There have been arguments that the Cardinals should have waited until August to trade Rosen to maximize their shot at compensation. Two teams have managed to find a meaningful market for their backups at the end of the preseason in recent years; the Eagles got first- and fourth-round picks for Sam Bradford after drafting Carson Wentz, and the Jets managed to parlay one year of Teddy Bridgewater and a sixth-round pick into a third-round pick from the Saints this past year.

It's possible that the Cardinals might have managed to get a better pick if they waited to deal Rosen, I suppose, but I'm skeptical that this would be the same sort of market.

There's a big difference between Rosen and the likes of Bradford and Bridgewater. Rosen is a prospect that a team would be acquiring to serve as its long-term quarterback. But he hasn't exhibited any success at the NFL level. Bradford was a veteran with an established track record of competency who was supposed to keep Minnesota's head above water without Bridgewater. When the former Louisville product was traded to the Saints, it was to serve as a veteran backup to Drew Brees on a one-year deal with the idea that the Saints could recoup a compensatory pick the following year. Those were "right now" solutions. Rosen isn't necessarily a "right now" guy.

By making this trade, the Cardinals were also able to recoup the value of Rosen for a draft pick now as opposed to waiting until next year's draft.

The fit in Miami

For the Dolphins, the lure of taking a flyer on Rosen is obvious. The only quarterback of note on their roster is journeyman Ryan Fitzpatrick, who turns 37 during the season and has only $1.5 million of his 2020 salary guaranteed. He wouldn't be a meaningful hindrance to giving Rosen a shot as early as Week 1. Fitzpatrick would also hold some modest trade value if the Dolphins wanted to move on from the Harvard product.

Acquiring Rosen doesn't lock the Dolphins into him as the focal point of their rebuild, either. If he plays well, great. Miami found its QB for a late second-round pick and a fifth-rounder. If not, the Dolphins will have one of the top picks in the 2020 draft and can use that on a replacement while installing Rosen as their backup. This is a low-risk move that offers the possibility of an extremely high reward. It's a great bet by the Dolphins.