Hi, Occam here. This is just a map of the white/black ratio of each position. There is a 15 point difference between the mean IQ of European-descended (white) Americans and African-descended (black) Americans Please note this is something You Can't Say so don't speak publicly of it.

The most interesting thing to note here is that white players score about half a standard deviation higher than the national white IQ, and black players score about half half a standard deviation higher than the national black IQ. Since life is sort of an IQ test, this isn't too surprising. There are a lot bad decisions you can make to screw up your football career before making the NFL - a higher IQ will keep you away from these things.

As always Steve Sailer is indispensable in these matters: "Are football players dumb? Actually, they are fairly smart. The NFL requires draft prospects to take the Wonderlic IQ test. Offensive guards averaged 107, centers and punters 106, quarterbacks and kickers 104. The speed positions averaged lower: halfbacks, free safeties, cornerbacks, and wide receivers averaged from 91 to 94. Still, at both the white positions and the black positions, prospects scored about a half standard deviation higher than the respective white and black national means.

Of course, IQ tests do a lousy job of measuring improvisational mental ability, which football players, especially the black ones, are particularly good at. (See my classic article "Great Black Hopes" for the full story.)"

That article is here: http://www.isteve.com/blackath.htm