RB Metrics“Give me eighteen inches of daylight…That’s all I need”

-Gale Sayers

Running Back MetricsAmong the many positions data can help spark questions and solve problems for NFL scouts is the running back position.

Career shortening injuries, increased emphasis on the passing game and various high round busts have devalued the running back position over the last two draft classes.

However, athletic and production data can lessen the impact of that volatility to discover where the risks and rewards truly exist for NFL teams.

This slideshow will go over in detail the various types of athletic and production metrics I use to evaluate running backs, and how they can benefit in evaluating backs.

Athletic Metrics

Part 1:Explosive Lower Body Strength

Explosive Lower Body Strength Leg drive and general displays of power are common qualities scouts look for in running backs to gauge the ability to break tackles and push a pile for extra yards.

Film study can show a back’s ability to integrate their power on the football field, but not having a numerical increment to compare lower body strength across draft classes can create blind spots in evaluations.

And it’s hard to determine if a back can improve their ability to integrate power on the field if you don’t know how much potential power they have.

How to measure lower body strengthThe vertical and broad jump are the two main athletic tests to measure lower body strength.

The difference between the vertical and broad jump are the specific muscle groups that influence the results vary.

A study published in the Canadian Journal of Sports Sciences using force plate technology found that on the broad jump “the contributions of the hip, knee, and ankle muscles were 45.9%, 3.9%, and 50.2%, respectively, whereas, for the vertical jump the contributions were 40.0%, 24.2%, and 35.8%, respectively. ”

Explosive Lower Body Strength ScoreIs a formula that uses a running back’s mass density, vertical jump and broad jump results to boil a back’s lower body strength into one number.

The actual score isn’t as important as the ranking amongst other running backs, but the average lower body strength score since 1983 is .82.

The score is useful in identifying whether a running back has adequate lower body strength, and helps raise red flags to investigate if a self described “power” back doesn’t test very powerful.

Examples of successful backs with top 20 percentile lower body strength scores.

Part 2: Speed Score

SpeedShort area burst and long speed are common qualities that scouts look for in backs to gauge how much they can test defensive leverage in space.

Film study shows how much a running back’s speed can test leverage at the college level, but we often miss on prospects going by a pure eyeball test due to the increased speed of the NFL.

Long speed is considered overrated by some scouts, but every piece of a running back’s athletic ability factors into their success.

As well as identifying the best scheme a running back could win in the NFL.

How to measure speedThe forty yard dash has been consistently the most reliable measure for a running back’s speed.

The 10 yard split is often viewed as more important than the 40 yard dash, but the shortness of the time increases unreliability.

There have been no statistically significant differences between the 10 yard split and forty yard dash in terms of success, except for the 10 yard split being less accurate in gauging long speed.

Thus the 40 yard dash should continue to be the best measure of a running back’s speed.

Speed ScoreIs a formula that uses a running back’s mass density and forty time to boil speed for size into a single number.

The only issue to look out for in the speed score is the functional speed of running backs.

For example, a 6-3, 255 pound running back who runs 4.6 is very fast for his size, but 4.6 speed is not as functional as 4.4 or 4.3 to challenge defensive leverage.

This has rarely been an issue with the decreasing of size in running backs, but should show one way in how a speed score can be overrated.

Examples of successful backs with top 20 percentile speed scores.

Part 3: Dynamic Speed

Dynamic SpeedQuick feet and lateral agility are common traits that NFL scouts look for to gauge a back’s change of direction skills to test a defensive leverage in space.

Film study can show a back’s lateral agility or “quick twitch”, but sometimes speed can be mistaken for quickness on tape.

It’s very difficult to gauge the difference of quickness between player’s with the same speed.

Thus a method must be used to measure how dynamic a player’s speed is compared to other backs.

How to measure dynamic speedThe forty yard dash, short shuttle and 3-Cone times provide the data to measure dynamic speed.

The forty yard dash of course measures straight-line speed.

The short shuttle measures hip flexibility.

And the 3-Cone measures ankle flexibility.

These three measures when combined provide the most consistent measure for dynamic speed.

Dynamic Speed ScoreIs a formula that uses a running back’s mass density, forty time, short shuttle and 3-Cone to boil dynamic speed for size into a single number.

The majority of successful NFL running backs who ran 4.5 to 4.7 had good dynamic speed scores during testing.

Dynamic speed is often overlooked due to a lower success rate for back’s who only have this athletic skill.

However, studying the backs who were successful with dynamic speed can improve evaluation of prospect’s who only have dynamic speed as their most impressive athletic quality.

Examples of successful backs with top 20 percentile dynamic speed scores.

Production Metrics

Production MetricsAn often ignored aspect of the running back position is production.

Many scouts have asserted that running backs who have less mileage in college will last longer, and suffer less injuries in the NFL.

However, there are no correlations to back up the claims that chance of injury, or longevity of a running back is impacted by heavy or light usage in college.

In fact, the correlations favor higher usage in college toward gauging talent.

91% of 3-time All-Pro RBs since the 1983 draft were in the top 33 percentile of career all-purpose yardage.

84% of 3-time Pro Bowl RBs since 1983 had top 40 percentile all-purpose yardage.

Market Share YardageTotal career yardage is great, but single season total offense market share yardage shows higher correlations for successful running backs in the NFL.

In fact market share yardage is more accurate in assessing a back’s chance of long-term success in the NFL compared to pure athleticism.

77% of 3-time All-Pro running backs had top 17 percentile market share yardage or higher in their most successful college year since 1969.

100% of 3-time Pro Bowl running backs since 1969 had top 38 percentile market share yardage.

Examples of successful backs with top 12 percentile market share yardage since 1969.

Metrics and Draft Value

How to use these metrics to value prospectsThe combination of knowing where a running back stands from an athletic and production standpoint helps on how to properly value running backs.

Many of the “can’t miss” running back prospects like Trent Richardson did not have much evidence from a metrical standpoint to conclude “can’t miss” status.

Richardson’s metrics were more akin to a probable pro bowl caliber running back, but not a transcendent talent.

And the fact many successful running backs have gone in Day 2 and Day 3 only proves that the NFL does not know how to correctly evaluate running backs.

Case in point Le’Veon BellLe’Veon Bell was a running back in the 2013 NFL draft class who wasn’t very powerful for his size, but he had top 6 percentile dynamic speed and top 5 percentile market share yardage.

Based on those metrics Bell should have been a first-round value with greater emphasis in film study to examine similar backs with his numbers to aid in evaluating.

But the continuing devaluation of the position will give team’s great draft value due to current groupthink about the position.

By increasing the accuracy of who the truly rare prospects are from a metric standpoint is invaluable in where value exists from a historical perspective in any given draft class.

Marriage of Film Study and Metrics

Film Study and MetricsHitting on running backs starts first and foremost with film study.

Metrics is the body of a prospect, but film is the soul.

You know your instincts, and anytime you have to believe in numbers over tape you will likely miss.

Metrics should be used to back up your claims on tape, and help in properly valuing draft prospects.

However, anything that can bolster your claims, or help in raising red flags you didn’t see at first is beneficial to evaluation.

And I hope a few of the tools I’ve presented today can help in your future evaluations.

The EndYou can contact James Cobern at james_cobern@yahoo.com or on twitter @Jmcobern1 for additional information on metrics or for future consultation.