2014 was not a good season at cornerback for the Jets. Darrin Walls played the most cover snaps at the position for Gang Green with 448. In those snaps, PFF says he was responsible for 52 catches, 894 yards, and 6 touchdowns. Those numbers tell the story. Only three cornerbacks in the league allowed more total yards and only eight allowed more touchdowns.
Walls wasn't always soundly beaten. As much as anything, his lack of ball skills were the culprit. There were plenty of instances where he was in good coverage and just was unable to locate the ball and position himself to make a play.
Walls will be 27 before the next season starts. He is slated to make a shade over $1 million. The Jets owe him nothing if he is released. I think this is a case where moving on would make sense. Even if the Jets sign somebody at an equal skill level, they can get him for cheaper and save a small amount of money. I'm not sure there is a ton of upside with Walls. He was with the Jets for years, and his issues seem to be instinctual more than athletic or technical. If the light has not come on yet, I'm not sure there is much to suggest it will in the future.