I feel the position of CB is the most inconsistant performing position on the field and chance/luck has a lot to do with having a stand out season. I get so frusterated when CB run back to the huddle, chest bump his fellow DBs, after a ball bounces off the WR hands. While the fortunate occurance has nothing to do with the CB, but these plays are the difference between having a pro bowl season and getting cut by the Raiders.
For example, take a look at Deltha ONeil.... he gets beat over and over however he remains on a NFL roster. If you look at his career, he actually made two pro bowls but I believe his performance those seasons were purely a product of quality DB support, strong time of possession, and fortunate bounces.