by Andrew Healy

In 2013, Trumaine McBride posted the best charting stats of any cornerback in terms of both adjusted success rate and adjusted yards per pass allowed. Now, the rental car agreement-length disclaimer in that article made clear that although McBride had posted the best numbers for that year, he was in no sense the best corner in football. Still, McBride's ascension to the top of the heap certainly felt odd, and his performance was not repeated in 2014 in his limited snaps. (McBride was slightly above average, on only 15 charted targets.)

To get more meaningful rankings this year, we made a change in last week's "best cornerback stats" article: we split cornerbacks into two groups, No. 1 corners and others, imperfect though those distinctions may be. However, after reading some of your feedback, we wanted to do a little bit more to try to reduce the volatility in cornerback charting stats. So instead of just ranking by one measure, this week we rank players by an average of our two main measures, adjusted success rate and adjusted yards per pass. Doing this kind of averaging usually leads to more reliable and stable measures in social science research.

Even now, these stats constitute just a piece of a larger player evaluation puzzle. The top-ranked player is still not necessarily the best. But the averaging should make this a little less like the World Series of Poker, where the winner sometimes might not even be that good at poker (e.g., Jamie Gold, for those of you keeping score at home), and more like a situation in which the top prizewinner is likely to be very good even if not the absolute best. Kind of like the NFL playoffs.

As with last week, corners are divided up as best we can into No. 1 corners and others. In all cases but two (Vontae Davis and Chris Harris), we simply defined the top corner for a team as the one who faced the most targets against opponents' top receivers (itself not always perfectly clear). This leads to clear definitions in many, but not all cases. Reasonable alternatives for the No. 1 corner could be offered for some teams such as the Eagles.

Last week's article has the sundry details and disclaimers, so let's jump right into the stats. I will be briefer with the discussion of the best corners since much of that appeared in last week's piece. Since adjusted success rate and adjusted yards per pass are on different scales, I turned each into a z-score before averaging them. All cornerbacks are then ranked by that average of the two z-scores, which I call "Corner Index."

"Leading Role" corners are ranked below out of the 32 No. 1 cornerbacks. "Supporting Role" corners are ranked out of the 45 other cornerbacks who had at least 50 charted targets and eight games started.

Best Cornerbacks in Leading and Supporting Roles