A stop watch, a scale, and a prayer - drafting a running back

TJ JohnsonMar 31, 2010 3:30 PM

Give me a running back with the power of Walter Payton and the speed of Eric Dickerson.  Now you've got a guy who can take you to the promised land.  But, unfortunately, a guy like that only comes along every 50 years.  And we've already seen in our lifetime a guy named Bo Jackson. 

--TJ Johnson

In the last several weeks, I've become MHR's version of a big-bad-bangin'-cold bucket of water.  I've compared the draft to a crapshoot.  I've compared it to blackjack.  I've even railed against drafting the most talented wide receiver this year, Dez Bryant, because he was late for practice, games, and most recently, forgot his cleats for his pro day.  It's gotten to the point where I am sure that Jeremy Bolander, E.J. Ruiz, and Sayre Bedinger would rather me retreat to my statistical cave and churn out a few more articles on Expected Points Value.  In NFL fandom (not to be confused with fandago, hombre), the NFL draft has become second fiddle to only Tom Brady's girlfriend/fiancé/wife and the annual Oakland Raiders coaching change.  Better to leave the draft analysis to the professionals...and Mel Kiper, Jr.

It in in this spirit, I offer up a little olive branch to all those draft geeks in MHR-land.  I thought I would use statistics for good rather than evil.  In fact, by the time you finish reading this article, your significant other will be thanking me.  I'll have saved you a good deal of time--perhaps enough time to clean out the garage this weekend.  That's becase I'm going to tell you how to draft a running back without ever again using Youtube, Google, Todd McShay, or your own brain.  So, my fellow scarecrows, follow me after the jump and leave your brains at the door.  Raiders Fans, ignore that last sentence.  For you, it's redundant. 

Al Davis: Super Genius? 

Put down your tape and shred your scouting reports right now! 

Al Davis was right!  40-yard dash times do matter--well, sort of.  And only for running backs. 

Bill Barnwell, with the Football Outsiders, came to a rather straightforward, logical, and obvious conclusion in the last several years.  For a running back, speed alone isn't sufficient for NFL success.  Usually, speed comes at the price of power.  And it doesn't take but a few hits from a guy like Ray Lewis to send a speed guy to the locker room for smelling salts.  This is why 40-yard draft times alone don't tell the whole story. 

And neither is power sufficient.  Power guys might be good for a 4th-and-1, but they'll never have the complete skills to be an every-down running back.  And the most powerful guys usually end up playing tight end, fullback, or linebacker.  This is also why a player's weight doesn't tell the whole story. 

For these reasons, Barnwell's cute and cuddly equation, known as the Weight-Adjusted 40-Yard-Dash Score (WA40), has particular appeal.  It simply combines speed and power into a nice little mathematical package in order to rank running backs entering the draft:

200 x Weight in Pounds / (40-Yard-Dash Time at Combine)^4

For those who would rather have a narrative version, we take the player's weight, multiply it by 200 and then divide this number by their 40-yard-dash time taken to the 4th power.  And you told your high school mathematics teacher you'd never use this stuff.  Little did your teacher know you would turn into a lazy, good-for-nothing draft lunatic. 

The WA40, according to Barnwell, has a moderately-strong correlation (.45) to a running back's future carries and yards in the NFL (using data from 1999-2008).  As such, I'd consider it a decent-to-average benchmark for evaluating running backs.  So for those of us who aren't a draft whiz (Matt Millen or our friend Al Davis), it can be useful indeed. 

The average NFL running back scores 100 on the WA40.  The highest WA40 score, according to Barnwell, was Brandon Jacobs, who ran a 4.56 40-yard dash and weighed in at 267 pounds.  His WA40 score was 123.50.  The lowest score was Darrin Davis, who ran a 4.82 40-yard and weighed in at 189 pounds.  His score was 70.03. 

With this in mind, we can apply this equation to previous drafts and to this year's draft as well to spot reaches, sleepers, and, yes, debate the Knowshon Moreno pick. 

The WA40 Time Machine

I decided to look at the Top-5 Running Backs drafted from 2008 to 2009 as a way to demonstrate Barnwell's equation.  Let's look at 2008 first:

2008

Pick

40-Time

Weight

WA40 Score

Darren McFadden

4

4.33

211

120.05

Jonathan Stewart

13

4.48

235

116.68

Felix Jones

22

4.47

207

103.7

Rashard Mendenhall

23

4.45

225

114.76

Chris Johnson

24

4.24

197

121.91

The first thing one notices is the strength of the WA40 scores of this draft class, in particular Darren McFadden and Chris Johnson.  In fact, when I looked at all of the drafts going back to 2000, this was one of the strongest Top-5 classes.  Perhaps this explains also why all 5 of these running backs were off the board by pick 24.  Going into the draft, one of the big questions was whether or not Chris Johnson was durable enough to stand up to an NFL- regular-season pounding.  Several years later, we know the answer.  However, looking back and using Barnwell's equation, one might have been tempted to rank him ahead of Darren McFadden, who the Raiders nabbed at pick 4. 

Here are the scores from 2009:

2009

Pick

40-Time

Weight

WA40 Score

Knowshown Moreno

12

4.5

217

105.84

Donald Brown

27

4.51

210

101.52

Chris Wells

31

4.59

237

106.79

LeSean McCoy

53

4.52

198

94.87

Shonn Greene

65

4.63

227

98.79

In contract to 2008, what stands out here is the weakness of the class with respect to their WA40 scores.  The highest scorer from this list, Chris Wells, would have finished 4th in 2008's class.  The same with Knowshon Moreno.  According to the WA40 equation, LeSeaon McCoy and Shonn Greene weren't even average NFL running backs. 

Does this mean I'm ready to blast Josh McDaniels for selecting Moreno with the 12th pick?  Not really.  The scores of both Wells and Moreno were very close, and using game tape (what a ghastly and barbaric concept), one easily saw Moreno's superior vision.  However, I'm certainly not drinking the Kool-Aid.  If we accept the premise that Barnwell's equation has any value, Moreno's a slightly-above average NFL running back.  The good news is that in Josh McDaniels' offense, you don't have to be Chris Johnson.  Pass blocking and pass catching are also at a premium.  And Moreno does both very well. 

But was he worth the 12th pick in the draft?  Inquiring minds want to know. 

An Orange Blast From the Past

Before we move on tot the draft class of 2010 (Spiller, Spiller, he's our man, if he can't do it, no one can), I wouldn't be doing MHR readers justice if I didn't bring up some of the historical Denver running backs and their WA40 scores:

Running Back

Year Drafted/Signed

4 0-Time

Weight

WA40 Score

Peyton Hillis

2008

4.66

240

101.79

LaMont Jordan

2001

4.57

234

107.3

Correll Buckhalter

2001

4.53

226

107.34

JJ Arrington

2005

4.4

214

114.19

Tatum Bell

2004

4.37

212

116.26

Selvin Young

2007

4.58

207

94.09

Mike Bell

2006

4.6

221

98.72

Ryan Torain

2008

4.64

222

95.79

Travis Henry

2001

4.61

223

98.75

Reuben Droughs

2000

4.66

215

91.19

Clinton Portis

2002

4.42

204

106.9

Quentin Griffin

2003

4.48

195

96.82

Olandis Gary

1999

4.71

216

87.78

Mike Anderson

2000

4.69

235

97.14

Terrell Davis

1995

4.72

210

84.62

This list alone is fascinating, but a few things stand out.  First, Barnwell's equation would suggest that Peyton Hillis was drafted in the late rounds for a legitimate reason.  Second, Denver signed J.J. Arrington again for all of that potential.  Third, Tatum Bell never really lived up to his potential (as a cell-phone sales guy, I've no stats).  Fourth, I never bought into the Travis Henry hype and now I have some numbers to confirm my intuition.  Lastly, and a major warning to all of us stats geeks to never go to battle with stats alone, Terrell Davis had the lowest score on this list.  Vision, scheme, work ethic, Howard Griffith, and Gary Zimmerman can take the WA40 Score and they can beat it all to hell.  Let us always remember, football is an 11-player game. 

I estimated Floyd Little's WA40 score at 259.89 (solve the equation if you'd like, Kentucky Bronco), but because they didn't keep official 40-yard-dash times in 1967, it's my own unofficial score.  The crazy thing is, Floyd ran that 40-yard dash last week. 

And Now, What You've Been Waiting For

After that walk down memory lane, let's look ahead to 2010.  Neither I, nor several hundred thousand of my Broncos friends, expect Denver to select a running back with their 1st-round-pick this year, but it's highly likely they'll take someone in the later rounds. 

So how does the 2010 draft class score?  Let's take a look at the top 15 running backs as ranked by Walter Football:

Player

College

40-Yard-Dash Time

Weight

WA40 Score

CJ Spiller

Clemson

4.27

196

117.92

Ryan Mathews

Fresno State

4.41

217

114.75

Jahvid Best

California

4.35

199

111.15

Dexter McCluster

Ole Miss

4.55

172

80.26

Ben Tate

Auburn

4.45

219

111.7

Jonathan Dwyer

Georgia Tech

4.59

229

103.18

Joe McKnight

USC

4.42

198

103.75

Montario Hardesty

Tennessee

4.49

225

110.72

Toby Gerhart

Stanford

4.53

231

109.71

Anthony Dixon

Miss. State

4.65

233

99.67

LeGarrette Blount

Oregon

4.62

238

104.48

James Starks

Buffalo

4.48

214

106.25

Deji Karim

Southern Illinois

4.37

210

115.17

Andre Anderson

Tulane

4.5

212

103.4

Joique Bell

Wayne State

4.65

217

92.83

No surprise who's at the top of this list.  C.J. Spiller, both on tape and with respect to the WA40 equation, tops this list.  But the equation would suggest that Dexter McCluster may not be as good as advertised (did he really run that bad at the combine?),  and if I'm the Broncos and I'm sitting in the 4th or 5th round, I don't hesitate grabbing Deji Karim.  His WA40 score is 2nd only to Spiller's. 

So what do you think?  Are you buying Barnwell's equation?  Can statistics prove wiser than John Clayton?  Feel free to run the equation on other backs, both present and past.  My favorite, and to whom I reference in my initial quote, is Bo Jackson.  It's been said that he once ran the 40-yard dash at 4.12.  Now, this is before they used electronic stop watches.  But at 227 lbs.,  even a 4.3 would have been absolutely deadly, resulting in an earth-shattering WA40 Score of almost 133.