Charles Tillman and the forced drop

Posted by ESPN.com's Kevin Seifert
Our friends over at Football Outsiders are always looking for new ways to identify statistical trends that unveil notable but sometimes unseen achievements. In an ESPN Insider piece this week, FO dug up an interesting -- if ultimately limited -- distinction for Chicago cornerback Charles Tillman.
Based on film breakdowns of the 2008 season, more NFL receivers dropped passes when Tillman was the primary defender than any other cornerback in the league. Of the 113 passes thrown in his direction, 10 were dropped. For the purposes of this study, FO defined a drop as an "uncontested pass the receiver should have caught." Imperfect passes or those knocked away by simultaneous contact didn't count.

Under those terms, "forcing a drop" would seem to be an oxymoron. By definition, receivers dropped the ball under no particular duress from opponents. That would make drops more of a coincidence than a reflection of a defender's skill. The statistic could also be inflated by the number of times a cornerback is thrown at.

On the other hand, we've all heard so much about the intimidation factor -- the mental register a receiver makes of a cornerback's presence. Could Tillman's reputation as a physical corner -- or, more specifically, his well-known ability to strip the ball -- impact a receiver's concentration?

It makes intuitive sense, and I'm sure there have been instances when a receiver loses concentration because he's aware Tillman is preparing to swipe at the ball. But Football Outsiders' study offers no evidence to suggest Tillman has consistently "forced" receivers to drop the ball during his career. In 2007, for example, receivers dropped four of 93 passes against him, which finished below the NFL average that season.

My own opinion: If forcing drops is a skill rather than coincidence, it's one built by reputation over time. I'm not willing to completely write off this category as a fluke. The mere presence of a physical cornerback can impact at least some weak-minded receivers.

What do you think?