Buffalo Rumblings has a good article talking about the percentage of balls thrown by Cam to Benjamin that were catchable, etc.
"Cam Newton led all passers with 17 percent of his passes overthrown, and that number would have been higher without Benjamin's tough catches. Based on our breakdown of incomplete passes in game charting, 27.0 percent of Benjamin's targets were deemed uncatchable (27th-most). For comparison, only 16.2 percent of Beckham's targets were uncatchable (81st). Benjamin had 15 above-the-head grabs among his first 40 catches of the season, an absurd rate. He finished with 19, second only to Beckham's 20. His season percentage of catches caught above the head (26.0 percent) is nearly three times higher than the average studied (9.2 percent)."