Crowded Airspace: How Does Zac Stacy Fit With the New York Jets?

Zac Stacy floundered in St. Louis. Will he be able to crack the Jets' depth chart?

Sometimes life works in funny ways. On Thursday night, I mentioned on Twitter that my top choice for best move on Day 1 of the NFL Draft was the Detroit Lions for being able to trade down with the Denver Broncos, pick up a boatload of draft selections (not to mention a proven veteran), and still get their original target.

One of my Twitter friends then mentioned that he didn't like the Chargers' trade up and selection of rookie running back Melvin Gordon. This was what our interaction resulted in.

Sure enough, just two days later, that same Zac Stacy was traded by the St. Louis Rams for about the value of a bus pass.

The Rams sent Stacy packing for a mere seventh-round pick (224th overall). The most interesting part of this deal was not the deal itself but rather who made it. The New York Jets decided that the former near-thousand-yard rusher was worth a cheap flier, and added Stacy to their roster. The only problem with this: Stacy now joins an already stuffed depth chart that contains two players with basically the same downhill running skill set in Chris Ivory and Stevan Ridley.

Will there be enough landing strip for Stacy to touch down in North Jersey, or will he be put in a holding pattern indefinitely?

Now Boarding

We already examined the crowded Jets' backfield in a previous article, but this makes things a little more interesting. Now we have to factor in a third candidate for the "big back" role, and he brings his own unique questions to this discussion.

In order to understand the fit of Stacy, we have to look at Stacy's track record first. Having only been drafted in 2013, Jeff Fisher's regime gave up on him awfully quick -- same as they're now doing with Tre Mason. How has he performed in his two years in the league, if he found himself on the roster bubble so quickly?

We can assess Stacy's value through both traditional box score stats and an advanced, weighted analytic, the famous numberFire Net Expected Points (NEP). NEP helps us take the numbers we see in the box score and assign them contextual value as they relate to the game on the field. By adding down-and-distance value and other variables, we can see just how much each play and each player influence the outcome of the game. For more info on NEP, check out our glossary.

The table below displays Stacy's production in traditional statistics first, both rushing and receiving. What do we find?

YearRush Yd.YPCRush TDRec Yd.YPRRec TD

Despite being drafted in the fifth round in 2013, Stacy usurped prospective starter Daryl Richardson -- ironically, his teammate once again in New York -- for the lead back gig, and cruised to just under a 4.0 yards-per-carry mark on 250 attempts.

After receiving 285 total touches in his rookie year, he appeared poised to lead the 2014 iteration of the backfield too, but instead was usurped himself by Mason. Still, in a strictly relief role, he racked up the same yards-per-carry as his rookie campaign and even increased his yards-per-reception. He certainly produced less than Mason but created exactly what we expected out of him: no more, no less.

With the drafting of Todd Gurley at 10th overall this year, however, Stacy had had enough and asked to be traded. He believed that his production spoke for itself and that he didn't deserve to be relegated to third-string on the depth chart. Based on his box score, I agree: diminished opportunity diminished his value in 2014, and that was seemingly all. But was there more under the surface?

The table below shows Stacy's career thus far in terms of Rushing NEP and Reception NEP, as well as his ranks among running backs with at least 50 carries. Do his numbers hold up?

YearRush NEPRush NEP/PRec NEPRec NEP/Target
2013-10.41 (46th)-0.04 (t-32nd)5.49 (36th)0.42 (37th)
2014-14.05 (60th)-0.18 (69th)9.02 (32nd)0.39 (19th)

It's one thing to chalk up his diminished yardage totals to waned opportunity, but he actually performed worse in 2014 with fewer touches on the ground, to the point where just four running backs had worse per-attempt Rushing NEP than he did. He was no star in 2013 either; his 46th-ranked Rushing NEP was well below average.

Even his supposed improvement in the receiving game wasn't that drastic: he only increased his raw Reception NEP by about 3.5 NEP, and his per-target Reception NEP was actually worse in his sophomore year, despite the higher ranking. Stacy's behind-the-box score numbers appear to indicate that he wasn't worth it to keep around in St. Louis.

What will happen when he gets to New York?

Flight Delay

We've discovered that, despite a decent output, Zac Stacy should have been able to do a lot more with his touches the past few years. Now that we know how bad Stacy's been, how does he match up to the incumbents in New York, Ivory and Ridley? The table below compares the three power backs in the Jets' backfield by their Rushing NEP output over the past two years. Who will likely rise to the top?

YearPlayerRush NEPRush NEP/PSuccess Rate
2013Chris Ivory-1.90-0.0139.01%
2014Chris Ivory-8.51-0.0442.71%
2013Stevan Ridley-11.61-0.0746.63%
2014Stevan Ridley-1.98-0.0247.87%
2013Zac Stacy-10.41-0.0446.75%
2014Zac Stacy-14.05-0.1838.00%

We discussed in our last article on the topic that while Ridley has been a little more consistent, Ivory just has more upside in a given season and on a per-play basis, mainly due to his flat-out speed. Stacy falls below both of them in the talent pecking order by a mile. Given the fact that both Ivory and Ridley have guaranteed money on their contracts and Stacy does not, this puts him a solid third place at the power back position for the New York Jets.

Full Upright Position

One last thought, though. If Stacy is likely this far behind his teammates in the pecking order without even setting foot on the field, why would the Jets have invested the cost of a seventh-round pick in him? It's not a great cost, but it is something they could have used elsewhere.

The pick they sent for him -- 224th Overall -- is actually the lowest value on the traditional Jimmy Johnson value chart, with a mere draft cost of 2. Interestingly, too, the average seventh-round draft pick spent on a running back has a value of 1.76, just about the 225th Overall pick. We've found that on average, seventh-round backs last in the league less than two years; Stacy has already survived two years in the league, and this might have made it worth it to them.

By swapping this pick, if they didn't see anyone they liked to draft, they got a fifth-round runner for nearly the price of nothing. Not a bad deal, even if it isn't likely to pan out for them.