Will Adrian Peterson leave Minnesota for a warmer climate in 2015?
25 Feb 2009
Right around the time you see offensive linemen running 40 yards downfield for the first and last times of their NFL careers, it's reasonable to wonder whether the NFL scouting combine is really just a big waste of time -- an excuse for NFL teams to spend hours trying to figure out whether a player's bubble (read: posterior) is too big or his hands are too small, or that he doesn't run patterns well against a set of orange cones.
So then, is the combine worthless? Is it safe to throw out all the data and just look at how a player performed on Saturdays against inferior competition? No one has bothered to actually go back and check whether what happens at the combine bears any relationship to NFL performance -- besides us, that is.
The answer is that, well, it depends on the position and the player. One place where a bit of combine data can actually go a long way in predicting a player's viability in the NFL is at running back, where we've come up with a metric known as "speed score."
Speed score (explained in detail in PFP 2008 and in this 2008 article) takes into account each player's 40 time and weight to produce a number scaled around 100; the average speed score for a drafted back is 102.4, a number which rises to 111.1 for backs taken in the first round. The formula -- (Weight x 200)/(40-yard^4) -- adjusts the minuscule differences in 40 times from player-to-player by accounting for the weight each player has to lug around on his 40-yard dash. The result is a metric that has a stronger correlation to NFL performance on a one-year, three-year or five-year stretch than any other combine drill, including the standard 40-yard dash.
Last year, speed score pegged Chris Johnson (121.9) as the best back in the class, with Darren McFadden (120.0) and Jonathan Stewart (116.7) shortly behind. It predicted Matt Forte' (109.7) to be a sleeper, while believing that Ray Rice (99.8), Kevin Smith (98.6) and Steve Slaton (96.9) would struggle. Speed score is certainly not a foolproof indicator, but as you can see from that level of performance, it can be a useful one.
One really interesting case in upcoming seasons will be that of Felix Jones, who had a speed score of 103.7 despite being regarded as one of the fastest players in college football. His 4.47 40-yard dash certainly wasn't an impressive number (compared to the Chris Johnson's and Darren McFadden's of the world), but Jones showed off elite speed and blazing athleticism as a change of pace back and return guy in Dallas this year. Jones led the league in DVOA for backs with 20-99 carries, averaging a ridiculous 8.9 yards per attempt.
On the other hand, Jones only got 30 carries because he spent most of the year sidelined by a torn hamstring muscle. It's impossible to say if Jones is likely to be an injury-prone player at the professional level, but the possibility also exists that speed score does reveal something about a player's likelihood of staying healthy enough to accrue yardage as a professional; perhaps, if a player isn't fast enough or a good enough athlete to avoid taking a certain amount of hits at certain angles, he's more prone to suffering injuries, and speed score captures that. I'm not sure whether I believe that's the case or not, more just me thinking aloud.
The possibility always exists that Jones could just end up being a bust, anyway. The list of guys who averaged more than seven yards a carry in 20 or more attempts is: DeDe Dorsey, Jerry Ellison, Lorenzo Neal, Thomas Sanders, Ahmad Bradshaw, Tony Nathan, Darrin Nelson, Lamont Jordan, Brian Mitchell, Davi Meggett, Rock Cartwright, Sylvester Stamps, Michael Wiley (who did it two years in a row, was cut by the Cowboys, and never played in the NFL again), and Chris Fuamatu-Ma'afala. If we changed the somewhat arbitrary cutoff to 6.5 yards per carry, we could finally throw in some famous names: Kimble Anders, Bo Jackson, and Mercury Morris. What that all tells us? 30 carries is a pretty small sample size.
|Speed Score For 2009 Running Backs|
|Player||School||40 Time||Weight||Speed Score|
|Andre Brown||North Carolina State||4.49||224||110.2|
|Ian Johnson||Boise State||4.46||212||107.2|
|Javarris Williams||Tennessee State||4.52||223||106.9|
|Beanie Wells||Ohio State||4.59||235||105.9|
|Mike Goodson||Texas A&M||4.54||208||97.9|
|Bernard Scott||Abilene Christian||4.56||200||92.5|
|Javon Ringer||Michigan State||4.60||205||91.6|
|Branden Ore||West Liberty State||4.67||214||90.0|
|Gartrell Johnson||Colorado State||4.71||219||89.0|
|Note: Some times are unofficial|
The 2009 crop of running backs isn't as highly regarded as last year's, a group that produced five first-round picks. That's borne out by their speed scores. Knowshon Moreno, regarded as the draft's top back, ran a disastrous 4.6 40-yard dash that yielded a speed score of only 96.9. Even if you go with the time of 4.55 that has also been unofficially reported for Moreno, his speed score would be only 101.3, putting him just below Chris Perry (102.7).
Going back to 1999, that would be the lowest speed score posted by a first-round pick; the only two backs selected in the first round to post a speed score under 100 are William Green (98.7) and Trung Canidate (99.3). Only one back in the 11 seasons we've got speed score data for made it to the Pro Bowl after posting a speed score below 98.0: Brian Westbrook.
In his defense, Moreno's regarded as having elite agility, which goes unmeasured in the 40. Agility is measured in other drills, though, so if Moreno's agility was really at an elite level, we'd expect to see as such in the three-cone drill and the two shuttle runs.
In the three-cone drill, Moreno's 6.84 seconds were second to Abilene Christian back Bernard Scott. Scott also topped the leaderboard in the 20-yard shuttle with a time of 4.08 seconds, while Moreno was eighth at 4.27 seconds. (In the 60-yard shuttle, which we don't track data for, Moreno finished fourth out of the six who attempted it.) Over the past ten years, the average back who's been drafted has been 5'10" and weighed 216 pounds -- almost a mirror image of Moreno's 5'11", 217-pound frame. Those same backs have averaged a 20-yard shuttle time of 4.20 seconds and a three-cone drill time of 7.07 seconds. While Moreno's three-cone drill score was better than average (and would rate as the fourth-best time for drafted backs), success in the three-cone drill actually bears a slightly inverse correlation to NFL success, while the shuttle, which Moreno was below-average in, has a much more positive relationship.
While Beanie Wells' 4.59 40-yard dash almost perfectly mirrored Moreno's, the fact that he did so with 18 extra pounds on his frame produces a speed score of 105.9 (below-average for a first-rounder, but passable for a day-one pick). He actually profiles as rather similar to another Big Ten back: Larry Johnson, who was 228 pounds and ran a 4.55 40 at the 2003 combine, yielding a speed score of 106.4. Unfortunately, Wells doesn't come with the 2006 Chiefs offensive line.
The two players who improved their stock the most are the two ACC products who sit atop the speed score leaderboard. North Carolina State's Andre Brown ran a 4.49 40 at 224 pounds; that compares comfortably with Tampa Bay's Earnest Graham, who ran a 4.50 40 at 223 pounds in 2003. The book on Brown is that of a versatile, injury-prone back without the speed necessary at the NFL level; speed score thinks he can be a useful player in the pros.
The fastest 40 time of the day for running backs belonged to the other riser, Virginia's Cedric Peerman, a back similar to Brown in both stature and proneness to injury. While Brown projects to be a mid-round pick, though, Peerman (before Sunday) rated out as practice squad fodder.
The reason why? Scouts fear that the 7 7/8-inch hands of Peerman will yield too many fumbles as a professional, despite the fact that he fumbled all of four times on 448 touches in college. Maybe the combine is a stupid idea, after all.
A final factor we don't know anything about yet is whether the literal change in playing field has affected what we should expect from players in the combine. This is the first year for the combine in Lucas Oil Stadium as opposed to the now-imploded RCA Dome, and without a real blowaway 40 time from any of the players at this year's event, there's been some chatter that the surface might not be of the same caliber.
If that's the case, well, the numbers sure don't show it. The average 40 time for this year's running backs was 4.58; the average 40 time for running backs from 1999-2008 was 4.57. At wide receiver, the average 40-yard dash this year was 4.51, actually three-hundredths of a second faster than the 1999-2008 average of 4.54. If the new field's slowing guys down, it's not showing up in their numbers.
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