Can Ka'Deem Carey Make a Big Rookie Impact for the Bears?

We all know by now that Marc Trestman is a wizard. Will his magic work on rookie Ka'Deem Carey?

Marc Trestman's impact on the NFL as a head coach is no longer a secret. It's not going to be a surprise.

At this time last year, numberFire's JJ Zachariason gave some good insight into what Trestman did as an offensive coordinator, and why fantasy football owners should take note of the potential impact he'd have on the Chicago Bears and their offensive talent. Now, a year later, every fantasy draft board is adjusted for the "Trestman Effect."

But what about the newest member of the offense in Chicago, Ka'Deem Carey? The Bears added the Arizona back in the fourth round of the draft, and he steps right into the second spot on the depth chart behind Matt Forte. So what can we expect from a new pawn in Trestman's game of offensive chess?

As JJ noted in the article linked above, Trestman made a big impact on the Oakland offense during his first year calling plays there. He had a similar impact on the Bears in 2013. The Bears posted a net gain of 110 Adjusted Net Expected Points on offense. Net Expected Points, or NEP, is numberFire's way of measuring how efficient a player or team is based on how many expected points they gain or lose based on their actions. The "Adjusted" part means we take into consideration strength of schedule when considering the team's NEP data.

To quantify the improvement in a different way, the Bears went from being outside of the top 20 in total offense (on par with the Dolphins and pre-Philip Rivers revival Chargers) to being in the top 10 (just behind the Colts and Seahawks, and ahead of the Packers and 49ers.) And while most of the improvement came in the passing department, that still helped out Matt Forte, who saw a big leap in production from year to year.

Forte saw improvements in every area of our metrics, including a career high in rushing Success Rate (or how often he gained positive NEP for his team when carrying the ball). But he saw an even bigger leap as a receiver, where he produced more than double the Reception NEP per target in the passing game than he had in 2012. His overall Reception and Target NEP (which measure the NEP gained or lost on his catches and his targets, respectively) were both career highs in 2013.

But when considering what Carey will do, we have to remember that Matt Forte is still in Chicago, and will still be the lead back in 2014. Despite his "always injured" narrative, Forte has the fourth-most carries in the NFL since 2008, ahead of Frank Gore, Marshawn Lynch, and Maurice Jones-Drew. He's missed only a handful of games in his career, and has been a reliable producer of yards for the Bears despite dealing with nagging injuries.

Carey will instead step into a role similar to the one held by Michael Bush over the past couple of years. Bush, unlike virtually every other Bear on offense, didn't see a big benefit from the arrival of Trestman. His workload decreased and he was simply not as productive as he was the previous season. Will Carey see the same fate?

The reason for the decline in Bush's productivity was the increase in passes thrown in Chicago in 2013. The Bears went from a 1.13 pass-to-run ratio in 2012 to 1.52 ratio in 2013. Yet Forte assumed his usual workload, meaning there were simply fewer touches for the other backs on the roster.

There's reason to believe that Carey would be productive if given the opportunity in Chicago, however. Using our READ metric, which evaluates a rookie's athletic profile based on similar players in recent history and projects comparisons based on rookie situations, we find that the most similar backs to Carey are LeGarrette Blount, Domanick Davis, and Alfred Morris, all of whom posted 1,000 yard seasons as rookies, combining for 27 touchdowns in their first seasons. However, all of these backs had more than 200 carries as rookies, something Carey doesn't figure to get.

But if he proves that he's capable in the passing game, he could earn his way onto the field more often. Michael Bush only had 13 catches in his two years in Chicago despite posting 37 his final year in Oakland. Carey logged just over two catches per game during his career at Arizona, to go along with over 20 carries per contest. If he can transition into being a more balanced back, and not simply a workhorse on hand-offs, he'd make a very nice compliment to Forte.

The reality is that Carey would need an injury to Forte to be fantasy relevant in 2014. The future is bright (assuming he stays out of trouble), but the short-term outlook for the rookie is restricted by having one of the most reliable backs in football ahead of him.