Which Running Backs Entering the 2015 NFL Draft Were Most Productive in the Red Zone?

With the NFL draft quickly approaching, the spotlight is getting brighter on the incoming class of 2015.

Let's continue shining it.

We already reviewed the most efficient running backs in this year's loaded class, and we'll add another production variable to the mix here and look at red zone production.

Truthfully, a running back's success will almost always hinge on offensive line play, a quarterback's effectiveness, coaching, and play-calling in a multitude of variations. The list could go on, but there are a litany of items that are tied to a running backs production. These factors could not be more true in the red zone, and if anything these variables are heightened inside of the 20-yard line.

Still, even though a running back's red zone success rate isn't as transferable as a wide receiver's or tight end's, it's still completely worthwhile to look in to these college prospects pay-dirt production.

Touchdown Prominence

As stated from the beginning, each of these running back's individual red zone success rate scores need to be taken with a big dose of context. It's hard to make an apples-to-apples comparison when college offenses are vastly different. These backs were on offenses on totally different ends of the surrounding talent and efficiency spectrum, so it's tough to compare each individual situation, especially in the red zone.

Below, you will notice four different columns focused on different statistical points. The first column garners the percentage of red zone carries a specific running back had on his team. To be clear, this percentage of red zone carries only measures running backs attempts -- no quarterbacks or other position's attempts were used.

The following columns are simply red zone carries, touchdowns, and those touchdowns inside of the 20-yard line divided by carries or red zone success rate (RZSR). The data is sorted in descending order by the highest red zone success rate score and the top scorer(s) in other categories are in bold.

Finally, while some running backs such as Todd Gurley were starters for three years in college, others weren't. To account for already small sample sizes, a running back must have had at least six red zone carries on a given year for that season to qualify. All of the statistics below are career numbers, and the data originated from the individual rushing situational splits at CFBstats.com.

Let's highlight some of the best and worst red zone success rate scores and add context to the numbers.

Karlos Williams 6’1”, 230 Pounds (Draft Age: 21) | Florida State

To be honest, the converted safety to running back Karlos Williams' 33.9% red zone success rate is a bit of a conundrum. On one hand, you look at his 230-pound frame and 94th percentile ''Speed Score" according to Player Profiler and say to yourself, "Duh."

But then you take a look at his sub-par production in 2014 and start questioning his success inside the 20-yard line. The closest picture we can paint of Williams operates under the theory that, while his physical profile looks great, his on-the-field product underwhelmed. The truth likely lies somewhere in the middle as freshman Dalvin Cook came in and stole the starting job from Williams mid-season -- but the smaller Cook's nose for the endzone (11.8% red zone success rate) wasn't as near as strong as Karlos Williams'.

Jay Ajayi 6’0”, 221 Pounds (Draft Age: 21) | Boise State

Our own Joe Juan covered Ajayi's solid athletic profile at length and while his overall production in 2014 sagged, he came on very strong in the red zone during his career amongst the 2015 class.

What's even more beneficial to Ajayi's cause and efficiency inside of the 20-yard line is the volume he received at Boise. No one saw more red zone carries (144) than Ajayi in this year's class, and his 59% of team red zone attempts finished second among the group.

While Boise State doesn't get the offensive line recruits like Florida State, Georgia, or Alabama does, Ajayi's red zone prowess is just another boon to his three-down ability. Here, you see Ajayi's excellent vision on display as he bounces the ball outside, makes a quick cut up field, and scores a touchdown.

Todd Gurley 6’1”, 222 Pounds (Draft Age: 20) | Georgia

Honestly, I'm not sure what context needs to be added here besides the fact that Gurley's 28.9% red zone success rate just further cements him as the most productive back in this year's class. In case you need a reminder, he was virtually impossible to tackle at Georgia.

Melvin Gordon 6’1”, 215 Pounds (Draft Age: 22) | Wisconsin

Similar to Gordon's advanced yardage splits, his 28.6% red zone success rate nipped at the heels of Gurley. And, also like Todd Gurley, there isn't really much to add to Melvin Gordon's case -- especially in the red zone. If anything, his numbers are slightly more impressive than Gurley's in a sense because he handled the fourth highest percentage of team red zone carries (49.1%) in this year's class and Wisconsin averaged one fewer red zone scoring attempt per game than Georgia.

Josh Robinson 5'8”, 217 Pounds (Draft Age: 22) | Mississippi State

Full disclaimer here: Robinson's overall profile is a bit soiled due to his horrific combine numbers, but he was fairly efficient in the red zone during his three qualifying seasons at Mississippi State. While his 26% red zone success rate finished sixth amongst the group and was slightly above average, there is another side to the story.

His 33.6% of team red zone carries finished 13th of 14 qualifying running backs, and quarterback Dak Prescott's running threat on zone-read plays may have boosted Robinson's red zone efficiency. While Robinson doesn't score on this carry, here is a good example of LSU's right defensive end hesitating a bit due to Prescott's presence and how the zone-read can open up running lanes for the back.

Duke Johnson 5'9”, 207 Pounds (Draft Age: 21) | Miami (FL)

Duke Johnson's below average red zone success rate (20.8%) was a bit of a let-down, but don't let that number trick you into thinking he isn't a crafty running back inside of the 20-yard line. Here is a two-play sequence against Florida State that illustrates his vision, explosiveness, and elusiveness all together.

On the first play, Duke makes a quick cut back to the inside and almost hammers the ball into the end zone before being tackled at the half yard line. The very next play, Johnson sees the left defensive end crashing down, so he bounces the ball outside towards the pylon for a score.

Tevin Coleman 5'11”, 206 Pounds (Draft Age: 22) | Indiana

In many ways, Tevin Coleman's low 18.9% red zone success rate deserves the biggest asterisk and the most context of the group.

First of all, Indiana was really bad on offense last year. The Hoosiers finished 110th out of 128 teams in red zone scoring attempts per game (2.6) and 87th in points per play (0.346), according to TeamRankings.com. Coleman rushed for over 2,000 yards and scored 15 touchdowns on a terrible team that went 4-8 in 2014, which is ultimately a net positive. Also, his low red zone success numbers are certainly tied to overall offensive efficiency -- Coleman only had 53 red zone carries combined in his sophomore and junior seasons -- which was the second fewest amount of carries inside the 20-yard line in our 15 running back sample.

Lastly, when Indiana did visit the red zone, the defense practically knew what was coming, and the Hoosiers offense didn't do a particularly great job of helping out their running back. Here is a perfect example of my point, where Michigan's defensive tackle comes in to the backfield unabated right after Coleman receives the handoff. Plays like that show up constantly when watching Indiana in 2014 and are a massive reason why Coleman's situational yardage splits and red zone success rate suffered.