I was browsing Football Outsiders earlier, and noticed that they had posted the speed scores for the 2009 tailback class now that the NFL Combine is in the books. It's a great read, and it's well worth the time. Long story short, speed score is a metric that takes size into account for a prospect's 40 time to get a better understanding of his raw abilities, and it is a metric that is being considered an increasingly valuable tool in evaluating prospects.
Alabama's Glenn Coffee, unfortunately, didn't turn out too well, after weighing in at 209 pounds and only running a 4.58 in the 40. That gives him a speed score 95.0, which puts Coffee a mere 15th out of a total of 23 tailback prospects running at the NFL Combine.
Meanwhile, Knowshon Moreno, as was discussed in the fanposts a couple of days ago, didn't do particularly well either. Despite all of the hype, Moreno ran a mere 4.60 after weighing in at 217 pounds, giving him a speed score of just 96.9. Even if you look at the absolute best unofficial time for Moreno, he still clocks in at only 101.3, putting him just behind 2004 draft pick Chris Perry (who, like Moreno, received a lot of hype coming out of a major program, and who eventually ended up being a complete bust after being a first round pick).
All in all, it's interesting work , and pretty insightful stuff as well. Going back to the 1999 NFL Draft, only two players with speed scores of lower than 100 have been drafted in the first round (William Green and Trung Candidate), both of which were busts. Furthermore, as far as the metric goes back, only player has made the Pro Bowl after positing a speed score of lower than 98.0 (Brian Westbrook). Generally speaking, the average speed score of drafted backs is 102.4, and the average speed score for first round draft picks is 111.1.