PFSN’s Cornerback Impact (CBi) assigns a numerical score and a letter grade to an individual cornerback's performance. The grade primarily reflects how a cornerback performs when targeted in coverage, but we've also factored in missed tackles and the ability to deter targets while playing a high volume of coverage snaps. There's also a small bonus for direct plays on the ball like passes defended, forced fumbles, and interceptions.

To qualify for the season rankings, a player must have played at least 100 coverage snaps. To qualify for game rankings, he must have played at least 10 coverage snaps.