One of the most compelling skill players in this draft is former QB Jerick McKinnon, the Vikings’ third-round pick to back up Adrian Peterson.

Former players like Ryan Riddle say that NFL coaching is focused more on scheme than skills development. It’s one of the reasons why I find player development in pro football so compelling.

Vince Young was a top-10 pick, but he worked at the game like a free agent. He spent roughly half of his career as one.

Regard Michael Vick’s career through the lens of Young’s experience and one earns a profound sense of how good the veteran quarterback was in Atlanta despite the fact that he never worked at the game. The Falcons brought in Steve Young exhort Vick (unsuccessfully) to develop a greater work ethic, but it took a prison term and a new team to see a notable change. Unless Vick stays healthy for another 3-5 years and transforms the Jets into a Super Bowl dynasty during his tenure, Vick will never reach the potential he once had.

Tom Brady and Priest Holmes are on the opposite end of the Young-Vick spectrum; they mined every ounce of their potential to become excellent pros. But there’s not just one axis that captures the nature of individaul talent development.

Draw a vertical axis than runs through Vick as the midpoint and place a talent like Ryan Leaf on one end and Randy Moss on the other and you have a spectrum that covers players with great physical talent that didn’t work hard at their games. Leaf’s range covers players that were spectacular failures. Moss’ range covers players that were unqualified successes.

I don’t know which axis Vikings’ rookie Jerick McKinnon will fit, but his athleticism, college career, and landing in Minnesota makes him one of the most compelling rookies I’m monitoring this summer. Minneapolis Star-Tribune blogger Master Tesfatsion reports that McKinnon has made a good first impression on Adrian Peterson:

When asked who has been the most impressive player so far, Vikings running back Adrian Petersonfirst bunched in all the quarterbacks, then he singled out someone who really caught his eye – rookie running back Jerick McKinnon. “He’s pretty impressive and there’s not too many guys who impress me like that, especially rookies coming in,” Peterson said. “He’s been able to do some real good things in the offense, picking it up well and just his running style.”

McKinnon was below the collective radar of the average NFL fan and mass media. He played at a small school (Georgia Southern), he was an option quarterback early in his career, and when he played running back he was in a triple option scheme.

These three factors didn’t keep him off the NFL’s radar. One of my contacts broached the subject of McKinnon last October. His team loved McKinnon’s athleticism and assured me that the Georgia Southern runner would run a 4.4-second forty. He also told me McKinnon could lift the gym.

My contact’s worst-case prognosis for a healthy McKinnon was a career as a valuable special teams performer, but he knew coaches that like McKinnon’s upside as a change of pace runner. Here is my talent profile on McKinnon from the 2014 Rookie Scouting Portfolio:

McKinnon has more upside than his ranking suggests (No.21 RB pre-draft) because he’s a fantastic athlete who has played multiple positions, including quarterback, defensive back, and running back. However, the limited tape of McKinnon as a runner—and non-existent game tape at Georgia Southern of him as an I-formation back clouds the decision-making process.

I see evidence that McKinnon can become a good NFL running back, but he’ll need to show that he can use his physical gifts with a deeper start from the line of scrimmage. It should give him and advantage, but it all depends on how he reads blocks. McKinnon carried the ball as a wing back motioning across the formation on sweeps or option pitches. He also worked as an option quarterback.

He has excellent burst during the first 15-25 yards of a run. In the game I watched where he got beyond that distance against a top-20 team (Florida), he lost his speed beyond that range. However, he was playing on an ankle injury that was bad enough that his coaches estimated McKinnon as 75 percent healthy.

His 4.41-second, 40-time is good enough to indicate that he has breakaway speed when at full health. What his tape shows is that he has the physical build of a running back and the willingness to attack defenders.

McKinnon flashes of good footwork to break behind a block and plant and cut with a sharp change of direction to cross the field. I’ve seen him use some spin moves in multiple games as an option quarterback in the middle of a run.

He occasionally slipped during his cuts, but it happened when he was making very difficult changes of direction where even agile pro runners fall. Even so some of his footwork is awkward when trying to make a move in the open field. He has the burst and outside speed to get the corner or make the first defender miss.

He finishes runs with good pad level and maintains good ball security to the sideline arm. He demonstrated some patience behind blocks on runs outside where he could press outside a block and dip back to the inside. When running as a wing back, I didn’t see him on plays were he had to display patience in a zone scheme. I saw no evidence of McKinnon running with his eyes, but I think this has as a lot to do with scheme.

Based on what I’ve seen of him in multiple games as an option quarterback, I think more room to get down hill earlier will help him set up moves better and break more tackles due to momentum. An NFL scout who broached the topic of McKinnon with me this fall said the runner would have a time around 4.45 in the 40 and that he was a workout warrior. There are clearly teams that have him on their radar.

He flashed some power, balance, and better cutting at the Senior Bowl but it’s only a glimpse into the adjustments McKinnon will have to make if a team considers him in May. Special teams may be his immediate future, but his speed, strength, and basic vision are worth building on.

There are two methods I use to grade players. The first is a checklist of defined criteria for each position I study. It has weighted values on a 100-point scale. The player earns these points based on evidence that he can perform each criteria as I define it. I complete this grading sheet by studying each play and documenting what I see play-by-play (Download Jerick McKinnon’s Sample).

The checklist score is a reflection of a player’s fundamental development. The higher the score, the more fundamentally sound he is to meet or exceed the baselines of what it takes to contribute in the NFL. However, this grading method does not completely demonstrate how good (or how potentially good) that player is with each category of skills.

After I study the play-by-play, I rate each player’s skills along a spectrum of talent. The dozens of criteria points on my play-by-play checklists are categorized under broader skill categories and its these categories I use to rate the talent level. For running backs the categories include power, balance, vision, acceleration, speed, elusiveness, blocking, receiving, ball handling, and durability.

The talent spectrum spans the following ranges:

Star – The player has rare talent in this area and his ability is among the top 10 percent of NFL players.

Starter – The player has enough skill in this area to start for most NFL teams if called upon.

Committee – The level of talent this player has makes him good enough to contribute in a rotation or temporarily start and perform well when called upon.

Reserve – The prospect can contribute and often perform well in this area, but without improvement there are enough prospects with equal or greater skill in this area.

Free Agent – A skill set with this label means the player needs to improve this aspect of his game or risk losing a roster spot.

Deficient – A lack of skill that needs development in order to make a team.

I was able to rate 9 of the 10 categories for McKinnon: 5 of 9 were starter-caliber; 3 of 9 where committee-caliber; and the remaining 2 were reserve-caliber. One of those committee-caliber ratings was for his balance, which I also labeled as an area I believe he could improve with ease. This is based on what I saw on film: McKinnon was playing with a bad ankle in the games I watched and I believe it impacted his balance.

I also labeled McKinnon’s vision as reserve-caliber, but I noted high upside based on what I saw in limited film situations as a quarterback as well as Senior Bowl practices as an I-back. What I gained from these processes is that McKinnon has starter athleticism and conceptual feel for the position that he could develop faster than it may appear.

The most compelling thing to monitor this year and/or next is how fast McKinnon picks up the nuances of running from the I formation and/or single back sets where he’s required to read the defense, demonstrate patience, and set up defenders in tight spaces. It’s common for people to say that running back is the most instinctive/intuitive position in the game. This is true, but it’s a simplistic assessment that’s overstated. Priest Holmes worked hard to become a more patient runner. So did Adrian Peterson.

The fact that Peterson is impressed is a good sign. It’s likely there is still a lot for McKinnon to learn, but the Vikings’ depth chart isn’t stacked with proven talent or great athletes at the position. It’s a good indication that the Vikings like McKinnon’s talent and they’re hopeful he can learn fast. If not, look for Minnesota to acquire a veteran later this summer or early fall.

For analysis of skill players in this year’s draft class, download the 2014 Rookie Scouting Portfolio. Better yet, if you’re a fantasy owner the 56-page Post-Draft Add-on comes with the 2012 – 2014 RSPs at no additional charge. Best, yet, 10 percent of every sale is donated to Darkness to Light to combat sexual abuse. You can purchase past editions of the Rookie Scouting Portfolio for just $9.95 apiece.