In the NFL Nation Mock Draft the Giants pick Saquon Barkley, but things could be different if Sam Darnold doesn't go No. 1 overall. (1:59)

The Cleveland Browns are going to select a quarterback with the first overall pick in the 2018 NFL draft. What happens next will begin to tell the story of this year's class. The New York Giants might draft a quarterback. They might trade the No. 2 pick. They might select one of Dave Gettleman's much-beloved hog mollies, such as Notre Dame guard Quenton Nelson or NC State defensive end Bradley Chubb.

The most popular pick for the Giants, though, is Penn State running back Saquon Barkley. Anyone who watches two minutes of Barkley's highlights can understand why Gettleman might want to keep the 21-year-old in the Northeast, as the tape suggests that he is a transcendent talent. He produced a nation-high 3,801 yards from scrimmage the past two seasons, and his 45 touchdowns tied him with Devin Singletary of Florida Atlantic atop the FBS leaderboard.

There's every reason to believe Barkley will be an excellent running back. The Giants have had six different backs rack up 100 carries over the past five seasons without finding a replacement for Ahmad Bradshaw, and they're currently projected to run out the duo of Wayne Gallman and Jonathan Stewart next season. Every team could use a Saquon Barkley. The Giants could really use one.

Should the Giants draft Barkley at No. 2? I don't think it's a great idea. That opinion has nothing to do with Barkley's considerable talent. I'm just not sure that the economics of the NFL and the running back market make it a smart decision to use the second overall pick on any rusher. Even if Barkley turns into a superstar, the Giants will be settling for a low-ceiling option if they draft him at No. 2.

To understand why that's the case, you have to look at both the recent draft history and the economics of the NFL under the current collective bargaining agreement.

When cheap is expensive

Part of the value of the draft is selecting players who will make a fraction of their true market value over the course of their rookie contract. Take Carson Wentz, who played at an MVP level in his second season before suffering a torn ACL. If Wentz were an unrestricted free agent this offseason, the 25-year-old would have no trouble finding a contract that would pay him $30 million per year for the next three seasons.

Instead of giving Wentz $90 million, if you prorate Wentz's signing bonus, the Eagles will be responsible for a total of $15.7 million over the next two years before picking up the quarterback's fifth-year option, which will be somewhere in the range of $22.8 million. (They could even franchise Wentz for another year at $27.4 million or so, but let's stop there.)

There's no stat that translates player performance into money, but we can use the current quarterback market to estimate what a top-tier passer gets in free agency to illuminate just how much of a bargain Wentz has been and will be if he continues to play at a high level. The top of the market was worth $25 million in 2017, will be somewhere around $27.5 million in 2018 and should hit $30 million when Aaron Rodgers and Matt Ryan sign their new deals. If Wentz continues to play at a Pro Bowl level and is one of the five best quarterbacks in football, he'll save the Eagles more than $75 million:

Year Prorated

contract Value 2017 $4,850,243 $15,000,000 2018 $6,062,804 $25,000,000 2019 $7,275,365 $25,000,000 2020 $8,487,926 $30,000,000 2021* $22,804,908 $30,000,000 Totals $49,481,246 $125,000,000 *Option

Of course, Wentz doesn't have to play at that high of a level to justify his current contract. The first four years of his deal amount to a total of $26.7 million, which is an average of $6.7 million per season. That's slightly more than the league's better backups will receive on their deals. (For example, Nick Foles originally signed a two-year, $11 million deal with the Eagles before renegotiating it this month.)

Even if you factor in an inconsistent debut season like his 2016 campaign, the upside for the Eagles is getting a quarterback worth $95 million while paying $26.7 million over the first four years. Even if you think Wentz has only a 30 percent chance of turning into that kind of superstar going into the draft, you're right to take a shot on a quarterback with the second overall pick. The numbers aren't and can't be exact, but you get the idea: The upside for drafting a quarterback is getting an absolute bargain.

When you do the same math for running backs, though, the numbers aren't anywhere near as appealing. There are only 11 active four-plus-year contracts for running backs.

You'll notice something interesting about the five largest active contracts for halfbacks:

Player Team Signed YRS Max

Value Guaranteed

at signing Annual

Average Four-Year

Cash LeSean McCoy BUF Ext. 5 $40,000,000 $18,250,000 $8,000,000 $35,125,000 Devonta Freeman ATL Ext. 6 $43,000,000 $17,000,000 $7,166,667 $33,500,000 Jerick McKinnon SF FA 4 $30,000,000 $12,000,000 $7,500,000 $30,000,000 Leonard Fournette JAC Draft 4 $27,150,842 $27,150,842 $6,787,711 $27,150,842 Ezekiel Elliott DAL Draft 4 $24,956,341 $24,506,340 $6,239,085 $24,956,341

Unlike rookie quarterbacks, who don't come close to making what the most expensive players at their position earn, highly drafted running backs such as Ezekiel Elliott and Leonard Fournette enter the league as some of the highest-paid players at their position. Elliott would probably top LeSean McCoy and make more than $8 million per year if he became a free agent, but upper-echelon running backs aren't coming close to the $25 million to $30 million annual going rate for signal-callers.

Le'Veon Bell will end up resetting the running back market next offseason, but it probably would take an MVP-caliber season for the Steelers star to get something in excess of $15 million per year. That's what Mike Glennon got from the Bears in free agency last offseason. No veteran starting quarterback on a multiyear deal will have a lower average annual salary than Bell, and he might be the only running back in football making more than $8 million per season.

Enter Barkley. The draft's second overall pick is locked into a four-year deal for something in the range of $32 million this offseason, all of which is fully guaranteed at signing. Before taking an NFL snap, Barkley would have more guaranteed money than any other running back in the NFL. He'd be tied with McCoy for the largest annual average salary for any running back on a multiyear deal. His four-year cash -- the money he would be in line to pocket over the next four seasons -- would be third in the league behind that of McCoy and Devonta Freeman.

Let's run the same table for Barkley that we ran for Wentz and assume a similarly favorable outcome. Barkley's $32 million is guaranteed, and former NFL executive Joe Banner projects that the running back would be in line to make about $13 million for his fifth-year option in 2022. Let's assume that Barkley plays at a Pro Bowl-level for each of the five years of his rookie deal without getting injured. Let's also assume that the market value of top-tier running backs will rise over the next five years by $1 million per season, despite the fact that their price tag has come down over the past five seasons, as Warren Sharp pointed out.

As a player entering the league as one of the highest-paid players at his position, even a very rosy outcome for Barkley has him essentially living up to his contract without providing any excess value:

Year Prorated

Contract Value 2018 $5,818,181 $7,500,000 2019 $7,272,727 $8,000,000 2020 $8,727,272 $9,000,000 2021 $10,181,820 $10,000,000 2022 $13,000,000 $11,000,000 Total $45,000,000 $45,500,000

The numbers above are obviously estimates, but you get the idea. Because Barkley is entering the league as one of the highest-paid backs in football, it's impossible for him to deliver anywhere near the sort of marginal value that would come from a rookie quarterback. The same would be true for a defensive end such as Chubb and would even qualify for a guard such as Nelson, given that top-tier guards now comfortably make more than similarly pedigreed running backs. That's without even considering that running backs get injured more frequently than players at any other position.

Exceptions?

To look past the economics and make the case that the Giants should draft Barkley at No. 2, one or more of the following three arguments would have to be true. And I'm not sure any is accurate.

1. The league has to be dramatically undervaluing top-tier running backs.

While the NFL has decided that Pro Bowl-caliber running backs are worth about only $8 million or so in this market, it doesn't necessarily follow that those backs should be worth that little. It's at least theoretically possible that the NFL could be underestimating how much running backs are worth to an offense and systematically underpaying guys such as McCoy and Freeman. If that were true, Barkley would be more of a bargain than his status within the running back salary structure as a potential second overall pick suggests.

While Gettleman has said that the league's devaluation of running backs is "comical," the problem is that there isn't much evidence suggesting that the NFL doesn't value running backs well. The market correction for halfbacks over the past 15 years is borne out by their shorter career spans and the success that teams such as the Patriots have had without committing to a franchise-caliber running back on a long-term contract. Of the past 10 Super Bowl winners, only two -- the Ravens with Ray Rice and the Seahawks with Marshawn Lynch -- were built around backs on top-tier multiyear contracts. The Saints had former second overall pick Reggie Bush in a rotation at halfback, but most of these teams were built around players on rookie deals or backs with middle-class contracts.

Furthermore, teams haven't really suffered when they've lost their star backs. The Cowboys weren't the same without Elliott, but the Jaguars' offense was better while Fournette was sidelined last season. In 2015, offenses around the league lost star backs such as Bell, Lynch and Arian Foster and actually improved.

The majority of big-money deals for running backs in recent years also haven't worked out. Carolina spent years desperately restructuring the deals Marty Hurney gave Stewart and DeAngelo Williams. Chris Johnson failed to make it back to the Pro Bowl after signing his extension. DeMarco Murray's deal in Philadelphia led him to be traded after one season. Even Adrian Peterson's six-year deal (which was restructured along the way) mixed one MVP season with two lost seasons and a third marred by injury. Lynch and McCoy have had the best outcomes among veteran backs since the current CBA was signed.

It's possible that the market could have overcorrected and might undervalue backs, but there isn't much evidence of that.

2. The chances of Barkley turning into a franchise back would have to be close to 100 percent.

The chances of a quarterback taken with the second overall pick turning into a franchise quarterback would have to be somewhere around 30 percent. The economic upside for a quarterback is clear, but if Sam Darnold or Josh Rosen has only a 30 percent shot of turning into the next Wentz, then the expected return for the Giants could be closer to $37 million than $125 million, which would level the playing field. (The valuation process is more complicated than that, but it works for the purposes of this example.)

Barkley is regarded as a truly stratospheric running back prospect and as close to a can't-miss proposition as you'll see in the draft. He has no obvious weak points or off-field concerns. He has been called the best running back prospect since Peterson. But as Scott Kacsmar pointed out, that has been true of Elliott, Fournette, Todd Gurley and Trent Richardson. Richardson was seen as a similarly safe pick with no significant flaws when he was drafted in 2012, but he turned out to be a sub-replacement NFL back.

Saquon Barkley rushed for 1,271 yards and added 632 receiving yards in 2017. AP Photo/Chris Knight

We're often too confident about the top running back prospect in a given draft class turning into the best halfback from his class at the professional level. By my count, looking at the past 20 drafts, the first running back drafted has turned into the best runner from that class only seven times. That's similar to rates at other positions. The first quarterback taken in each draft over the past 20 years has turned into its best passer five times. With edge rushers, it's six times in 20 years.

We still don't know about recent drafts, and it's a little unfair to compare a back taken in the top three picks to someone such as Bishop Sankey, who fell to the 54th pick of the 2014 draft before being the first back off the board. Let's take a look at the truly world-class running back prospects to try to find similar players to Barkley. It's unlikely that Barkley will fall past the Broncos at No. 5, given that the Giants, Browns and Broncos could all theoretically draft a running back or trade their pick to a team interested in Barkley. How often do top-five backs turn into superstars?

There have been 13 backs drafted in the top five in the past 20 years. Six of them -- Richardson, Cedric Benson, Bush, Curtis Enis, Darren McFadden and Cadillac Williams -- failed to make a Pro Bowl before their NFL careers ended. They have to be considered disappointments, though it's probably unfair to lump Bush into that mix.

Three backs made it to one Pro Bowl: Ronnie Brown, Jamal Lewis and Ricky Williams. Likewise, Brown probably doesn't belong in this group, given that he finished his career with 5,391 rushing yards, and Lewis and Williams each topped 10,000 over the course of their careers. It's also too early to judge Elliott and Fournette.

There are only two backs from this group who made it to multiple Pro Bowls and have Hall of Fame credentials. LaDainian Tomlinson is enshrined in Canton, and Edgerrin James is a two-time finalist and has a reasonable shot of making it one day. Of these 13 backs, I would say that four teams -- the Chargers (with Tomlinson), Colts (James), Ravens (Lewis) and Saints (Bush) -- ended up with a franchise back, while New Orleans was at least able to turn its disastrous trade for Williams into two first-round picks after three seasons, though one of them was conditional.

Let's say five teams found franchise running backs. That's not enough of a successful rate to trust that Barkley is a lock to turn into a perennial superstar. If we look back 10 more years, we'll find two more Hall of Famers (Marshall Faulk and Barry Sanders) and two total washouts (Ki-Jana Carter and Blair Thomas) alongside Garrison Hearst, who falls somewhere in between.

Do the same analysis for quarterbacks, and you'll get roughly similar results. Of the 27 passers drafted in the top five since 1998, three (Philip Rivers and the Manning brothers) are likely to make the Hall of Fame. It's still too early to judge a handful of those quarterbacks, but at least half of those teams came away with a guy they considered their franchise passer past their rookie deal.

If the chances of a highly drafted running back and a quarterback turning into a superstar are roughly similar, and it appears that they are, you simply can't justify taking the running back. There's too much upside being left on the table by not drafting a passer, given how much a good signal-caller makes relative to the cost of the second overall pick. The only exception would be if ...

3. The Giants think Eli Manning has five years left as a viable starter and they won't see much return on investment if they draft a quarterback with the second overall pick.

Given that Gettleman has suggested that he expects Eli to be the quarterback in 2018, it seems as if the Giants are at least operating under the assumption that their longtime starter isn't going anywhere anytime soon.

So let's ask that question: How much longer should the Giants expect Manning to play? The 37-year-old did complete another healthy season. But with his top two receivers missing most of the year because of injury and his offensive line more of a theoretical construct than actual protection, his numbers weren't pretty. Manning averaged just 6.1 yards per pass, the lowest mark he has posted since his rookie season, while his passer rating and QBR fell for the third consecutive season.

By the era-adjusted net yards per attempt (NY/A+) statistic, Manning's mark of 83 was well below the league average of 100. When you compare him to the 29 other quarterbacks who started 12 games or more during their age-36 seasons, that 83 NY/A+ figure ranks ... 30th out of 30. Granted, it's a list that includes 11 Hall of Famers and a handful of no-doubters who will be in once they're eligible, but last is last.

Excluding active players, the retired quarterbacks started an average of 18.7 games over the rest of their career. The 26 passers combined to produce a total of just 13 above-average full seasons as starters (12-plus starts with a NY/A+ over 100) after turning 37. Tom Brady and Drew Brees have outdone those marks, and it's fair to wonder whether quarterbacks are likely to last longer now than they would have 30 years ago, but the evidence suggests that Eli doesn't have much time left as a viable starter.

The most plausible time frame is that Manning lasts one or two more seasons with the Giants, given that he has two years and $33 million in new money remaining on the four-year extension he signed before the 2015 season. The Giants could free up $17 million by moving on from him after this season, and given that they'll likely be working on extensions for Odell Beckham Jr. and Landon Collins, that $17 million could come in handy.

Unless the Giants think Manning has four years of above-average play left in him, it doesn't make much sense for them to leave their best chance to fill the quarterback position for the next decade on the table. If they do think that Manning has that much left in the tank after three years of steady decline, the Giants are hoping as opposed to projecting.

The other suggestion has been that Manning will shoulder less of the load as the Giants transition to a run-heavy approach, a move that would be in line with drafting Barkley to serve as the team's primary back. Gettleman said after being hired that teams that win have to run the ball, stop the run and pressure the passer.

In a league in which teams are throwing the ball more than ever, it's a curious comment. The Eagles finished 17th in rushing DVOA last season and ran the ball with a bevy of low-cost backs. The Patriots, who nearly beat them in the Super Bowl, finished 30th in rush defense DVOA and 17th in sack rate. Those two teams threw for 878 yards in the Super Bowl and called 94 pass plays against only 49 runs. Good teams are often effective in those three categories, but they don't identify to be as meaningful or predicative as each team's performance with and against the pass.

Even if Gettleman is planning on building the Giants around running the football and stopping the run, that would seem to make an even stronger argument against paying a quarterback more than $20 million per year, as the Giants are currently doing with Manning. Now would be the perfect time to start developing a young quarterback whom the Giants can pay a relative pittance as they rebuild their offensive line. For a team that might still have one of the worst lines in football, even after handing Nate Solder a record contract, the idea to build around the ground game seems at odds with both these Giants and this era of football.

There just isn't a strong enough argument to take Barkley with the second overall pick over taking a chance on a quarterback, regardless of how good Barkley could end up. The Giants might regret passing on Barkley if he turns into a superstar, but given that they would be paying him like one of the league's top running backs before he ever steps on an NFL field, Barkley would need to be a perennial Pro Bowler just for the Giants to break even on his rookie deal. If they don't think any of the quarterbacks in the draft has any prayer of succeeding, Gettleman and Pat Shurmur would be better off trading down and grabbing multiple first-round picks for a team that is missing a generation of draft picks. Plus, they still need to address their future post-Manning, which is coming sooner rather than later.

Saquon Barkley could be an elite NFL player, but he isn't the right pick for the Giants at No. 2.