Running back is a position that has started to fall quite a bit out of vogue in recent years. The idea being that the quality of the running back matters a lot less than the guys blocking for him. The notion makes a ton of sense - undrafted players like Arian Foster emerge to prominence behind solid lines, as recent first rounders like Trent Richardson fail to make an impact. This idea has perpetuated itself, and was reflected in the most recent draft, as no running back went in the first round of the 2013 NFL Draft.

The 12th running back selected last year, Zac Stacy, may be the league's most impressive rookie of them all. Since Steven Jackson walked out, Stacy's emergence for the Rams has come at the perfect time, proving to be one of the more reliable backs in the league - both fantasy and real life - since given the starting job way back in Week 5.

And in a season where running backs have seemingly been all over the place, it's Stacy who's played exceptionally well, and, for the most part, consistently, since he's taken over.

All I Want, and I've Waited for So Long

It's extremely hard to compare rookies without considering where each one was drafted. As a smart man once said, "It's not so much about the players you do draft, it's about the players you don't."

Basically, the idea is that in both the NFL draft and fantasy drafts alike, selecting a player in the second round is much different than selecting one in the sixth, because you not only draft that player, but you also lose the chance to draft a different, possibly more valuable second-round player in his stead.

For purposes of this article, I chose to look only at running backs selected before Stacy in the 2013 NFL Draft who also had more than 100 carries in 2013. The reason I chose to look at it this way was several fold: to account for the fact that NFL teams who took backs after Stacy could not have taken Stacy, and I also felt it would be unfair to count guys who didn't play very much.

The one limitation here is that I can't necessarily account for where the player was taken in either NFL or fantasy drafts. Essentially, it's extremely difficult to assign a "value" to a pick in the second round of the NFL draft versus the sixth round, and likewise it's hard to assign a "value" to a second-round fantasy pick versus a waiver-wire pickup. In other words, I really have no baseline for comparison. Because of that, it's difficult to tell how well Stacy performed over his expected value, either as a real life NFL player or as a fantasy player, but I did my best to analyze that below.

In any case, there are only a few backs relevant for Stacy to be compared to: Giovani Bernard, Le'Veon Bell, Montee Ball, and Eddie Lacy. The other backs taken before Stacy did not qualify. I actually prefer it this way - the four guys that qualify happen to be the first four running backs selected in the draft, and all were hyped (to varying degrees) entering the season. All four went early in the NFL draft, and the Rams patiently waited and selected Stacy late. Yet, there's an argument to be made that they received the best value of all.

The raw numbers have Stacy right in the middle of that crew, per the table below:

Stacy ranks third amongst those backs in Rushing NEP per Rush, he's tied for fourth in Reception NEP per Target, and is tied for second in touchdowns scored. He has been consistently competitive in all of those categories, where no player ranks best in every one. And, in fact, the only guy to rank first in two categories is Eddie Lacy, who ranks very far behind everyone else in Reception NEP.

It's Just a Fantasy

Ultimately, what this comes down to is the fantasy angle: How good has Stacy been, relatively, in fantasy?

Stacy was the last to go of all of the players in consideration here, going undrafted or at the very end of almost every redraft. Most people shied away from the Rams running back situation, with considerations being made for Isaiah Pead and Daryl Richardson, both of whom ranked ahead of Stacy in preseason ADP.

Since Stacy took over the lead back role in Week 5, Stacy has been quite impressive fantasy-wise in his 11 games started.

Outside of Eddie Lacy, Stacy has had the most "big" weeks of any player - the difference being that you would have had to draft Lacy much earlier than you would have had to draft Stacy, if you had to draft him at all. Additionally, Lacy has had zero competition, and one more game played in that span than any other player - everybody else had their bye in Week 5 or later.

Though Lacy might be more impressive on an absolute level, Stacy looks to be alone as the second-most impressive back. But the key is you did not have to even draft him. You could have drafted another impact player in lieu of Lacy, and still wound up with the extremely effective Stacy. On relative value based on draft position, Stacy has been the best rookie back last year, due largely to his actual (and fantasy) draft position.

The question moving into next year is whether or not Stacy retains his opportunity. He has flourished in his opportunity, but as I mentioned earlier, the Rams have a bevy of backs, including the emerging Benny Cunningham. And, like Stacy, Cunningham wasn't even a factor in this mess of a backfield going into fantasy drafts. I would expect Stacy to get the bulk of the carries in 2014, but nothing would surprise me here. If he does wind up with the carries, I suspect Stacy will continue to be an impressive back - I just can't be confident that he keeps the opportunity as we might expect.