My overall impression on Leon Hall is that he's a fine cornerback. Though it always seemed his production was contingent on Johnathan Joseph's participation. Nothing to back that up, other than a curious focus that developed when opposing passing game moved the football often exposing our nature to point out that since Joseph is missing, it must all be Hall's fault. Not fair, we know. We're just human. Genetically engineered superhuman that would eventually inspire Khan Noonien Singh, that is.
Curious enough to put the work into it to actually differentiate the production, we decided to look into the matter (about Leon Hall, not us being genetically engineered superhuman). According to data from Pro Football Focus, which charts every play, Leon Hall allowed an opposing quarterback rating of 84.2 against targets that he covered throughout the season last year. During the four games that Joseph missed in 2010, Hall's opposing quarterback rating dropped (not rose) significantly to 71.8, with no touchdowns allowed and a completion rate of 55%.
Now this could be a matter of facing worse opponents at the right time. Then again Leon Hall only allowed four receptions of eight targeted receivers against the Atlanta Falcons for an opposing quarterback rating of 47.9. Hall allowed an opposing quarterback rating of 100 or more in six games -- only one of those games occurred when he didn't have Johnathan Joseph on the other end of the field. That's not to say that Hall was a bad cornerback when Johnathan Joseph played -- Hall posted six interceptions in 2009, playing all sixteen games with Joseph, posting an opposing quarterback rating of 52.6.
We're not sure if the trend of playing without Joseph will actually improve Hall's overall production (seems kind of a weird argument), but during their series ranking players, Scouts Inc. lists Hall as the league's 26th best cornerback. Nate Clements (30th), Adam Jones (68th), Morgan Trent (104th) and Brandon Ghee (136th) are listed inside the top 150. Johnathan Joseph ranks 17th, but thank god he's in Houston, otherwise Leon Hall would never find any peace.