While I’m happy to feel the oncoming arrival of fall, there is a part of summer that I miss the most when it leaves: the drifting nighttime presence of fireflies.

Fireflies, or lightning bugs as some regions call them, are small beetles that glow from their tail. In Minnesota, there can be thousands of them wafting around when dusk comes, like a sea of miniature airborne candles.

There is a small difference between those fireflies on the western side of the United States to those east of the Rocky Mountains: the western species shine, but very dimly and hidden in the grass, while the eastern species fly around aglow. For this reason, many people out west think there aren’t any fireflies out there at all. There are; they’re just tougher to find.

This seems very appropriate when we consider one particular NFL team’s running back situation heading into the 2018 season. On many other teams, it’s easy to spot the lead back -- the obvious fantasy football target -- but for the Seattle Seahawks, the glow is being hidden and many might think it doesn’t even exist, with the addition of Rashaad Penny in this year's draft.

But it’s there, and it’s Chris Carson who bears the shimmer that we should be searching for in our fantasy leagues. So, despite Penny's presence, here’s why Carson is the lightning bug you’ll want to catch in a bottle for fantasy football in 2018.

Creepin’ and Crawlin’

Not many people saw Carson's breakout coming last year, when the undrafted rookie exploded out of the gates for a solid 208 yards rushing on 49 carries (4.24 yards per attempt) in his first 4 games. He only scored once, and on a reception at that, but Carson still took the NFL by storm as his role appeared that it was certain to grow.

And then, tragedy struck. Carson’s debut ended with a broken leg in October, but he still resumed running in mid-December last year and reportedly could have gotten on the field if the Seahawks had made the playoffs.

Nonetheless, Carson’s ground production put him in the top third of the league during those first four weeks. Among the 63 running backs who saw at least 15 carries from Week 1 to Week 4, his 4.24 yards per rush was 20th, ahead of Todd Gurley, Le'Veon Bell, and Ezekiel Elliott. And all this despite being a completely unknown name running behind the second-worst run blocking offensive line in the league last year, by Football Outsiders’ Adjusted Line Yards.

Not shabby.

When we examine Carson’s production by advanced metrics, particularly by numberFire's Net Expected Points (NEP), he doesn’t hold up as well against the league. NEP is a metric that describes the contribution a play (or player) makes to their team’s chances of scoring. By adding down-and-distance value to the box score production, we can see just how much each play and each team as a whole influence the outcome of games. For more info on NEP, check out our glossary.

The table below shows Carson’s 2017 season in terms of Rushing NEP per attempt, Reception NEP per target, and Success Rate (the percent of plays resulting in positive NEP gain) for both rushing and receiving, with his ranks in these measures among the 74 running backs league-wide to top 49 carries last year, as well as among the 4 running backs on his own team.

While Carson was mediocre league-wide in the advanced rushing metrics, he was outstanding compared to the other rushers on his own team.

Putting his production in context behind 2017’s second-worst offensive line in the run game, we should be somewhat impressed that he was in the top third of NFL running backs. It’s entirely likely that offensive line is what did in most of his value, considering that no other Seattle back came within two touchdowns’ worth of rushing value when compared to Carson.

When given the opportunity to produce, it seems he did; in receiving value, Carson was a top-five back on a per-play basis. He could create in space and showed his big-play upside, but was crushed under the weight of a bad line.

Eventually, the promise of his 2017 season was crushed, too, but his fantasy profile has a glimmer again. Can Carson fend off a first-round rookie for the entirety of the season?

Beetlejuice, Beetlejuice, Beetlejuice

It’s always hard to know what a rookie will bring to the table, since we’ve never seen them produce in the league before and college football is a wholly different beast than the NFL.

There has been an even more spotty track record when a running back transitions from the Mountain West Conference -- not known for resilient running games -- to the pros. Some of the most recent alums have had some success (Jay Ajayi, Ryan Mathews, and Doug Martin come to mind), but quite a few others have been mediocre or downright bad (Ronnie Hillman, Jeremy McNichols, Donnell Pumphrey, Tyler Ervin, and recent Doug Martin come to mind).

Penny was selected out of San Diego State, one of the schools in this high-flying conference, but he is a bit of a different breed than the average back out there.

The table below shows the notable recent running backs from the Mountain West (formerly Western Athletic) Conference in terms of their ratios of rushes-to-reception and rushing yards-to-receiving yards.

Other than Mathews and Hillman, Penny was the most run-focused running back among these notable names. It’s no surprise that he’s primarily a bruising rusher, either, considering he stands a robust 5-foot-11, weighing 220 pounds, and he levied that bulk into an NCAA-leading 2,383 yards from scrimmage and the second-most total touchdowns in the nation (25).

And all of that is incredibly impressive, as is Penny’s draft pedigree (which will guarantee he gets plenty of chances in the future). That fact remains, however, that he is starting at a disadvantage to Carson due not only to his unfamiliarity with the system. Penny has been dealing with a broken finger that kept him out of preseason and reportedly has gained at least 15 pounds of weight in the offseason, as well.

Per RotoViz’s Jordan Hoover, only three running backs in NFL history have produced at least 150 fantasy points in their rookie season when entering the league weighing 235 pounds or more. Of those running backs, the ones with at least 50 rookie season touches posted just 106.3 PPR fantasy points on average.

Is it possible that the Seahawks look to run out their early-round draft darling this season and feature him? Sure, but there’s simply no reason to when Penny is potentially out of shape and ailing, and Carson has shown that he can produce.

Even the Seahawks themselves can admit it’s silly to force-feed touches to one player without purpose. You shouldn’t get scared off of Carson this year. So long as he's healthy, he should be able to hold on to the majority of work in Seattle.