Value-Scoring the 2013 NFL Draft

Lane Johnson with NFL Commissioner Roger Goodell after being named the #1 Draft Pick for the Philadelphia Eagles.The three day NFL Draft event is complete and many analysts have already submitted grades for teams as well as individual selections.  Admittedly, it’s a bit unfair to judge a team’s draft and their respective selections so early, before players have a chance to prove their worth on an NFL football field.   Instead, it may be better to grade the draft based on relative value (although, perhaps no less ambiguous).

Earlier, I created a draft model based on chaos theory principles and ran the simulation 1,000 times.  One of the byproducts of that simulation was an average draft position (ADP) for each player.  My goal was to use these ADPs as a basis for my value determination, but in order to do so I first needed to test whether my ADPs were relevant.  That is, did ADP relate any better to actual draft results than an analyst’s mock draft?  For a comparison, I chose Mike Mayock (I wanted to also use Mel Kiper’s latest mock draft but I’m not an ESPN Insider and couldn’t find it anywhere).

It turns out, the correlation coefficient (r-squared) for the first round of Mayock’s mock draft was .40 (p-value < .001).  In contrast, the r-squared for the first 32 ADPs of my model was .61 (p-value <.001).  And amazingly (to me, anyway), the r-squared for my model increases to .70 when including all seven rounds of the draft.  It appears then, that using the model ADPs as the basis for my value-scores is more relevant than Mayock’s (sorry, Mike).

In order to determine a value score for each selection, I subtracted the actual selection position from the model ADP.  Negative value scores are good.  They indicate the number of positions that players were drafted behind their ADP.  So negative scores represent “value”.  Positive scores, on the other hand, indicate players who were drafted well ahead of their ADP, and represent “reach”.

Here is a draft ranking of NFL teams from best average “value” to worst average “reach” per selection:

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In terms of value, the Arizona Cardinals, Minnesota Vikings, and Chicago Bears drafted best, followed by our Philadelphia Eagles.  And the team that reached the most with its draft picks was Andy Reid’s Kansas City Chiefs (This is just too appropriate… I swear I didn’t manipulate anything).

Here is more detail on how the Eagles and Chiefs drafted, with respect to their value scores:

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Although there was a huge amount of value (-74.28) in the Eagles’ Matt Barkley selection, Jordan Poyer was actually the draft pick with the most value in 2013 (-105.93).  And since the Eagles’ selections of Bennie Logan and Earl Wolff earned value scores greater than 32, it’s possible they could have been available in a later round and can be classified as slight reaches (in my opinion, any selection with a value score less than 32 can be considered good).  On the other hand, Kansas City’s third round selection of Knile Davis had an extremely poor value score (149.26) with an ADP in the seventh round, an extremely high reach.

Here are the top ten “value” picks, followed by the top ten “reach” picks:

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Time will tell whether these value scores hold any semblance of accuracy.  However, it’s comforting to see that the Howie Roseman/Chip Kelly tandem may have drafted better than Andy Reid.

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Jerome's Friend

Jerome's Friend is a native Philadelphian raised properly by great parents who taught him to love the Eagles and abhor the Cowboys. A new parent himself, he hopes to instill those same fundamental values in his son, who at five months-old can already spike a football. If you follow him on Twitter (@JeromesFriend), you'll also find his Eagles and Philadelphia sports blog, Philly's Inferno, where he resides as a Friend of Jerome.