Last season, cornerback was clearly the biggest weakness for the Detroit Lions. Resources were invested in changing that during the offseason, with a trade for Carlton Davis, the signing of Amik Robertson and using their first two draft picks (Terrion Arnold, Ennis Rakestraw) on cornerbacks.
Having viable cornerback talent in place has allowed defensive coordinator Aaron Glenn to marry blitzing with man coverage better than he could last season. To that end, with the sixth-highest blitz rate in the league (29.8 percent), the Lions are using man coverage at the highest rate in the league entering Week 10 (44 percent, according to Football Insights).
A lot was made (rightfully so) about Arnold's penalty issues early in the season, to the point there was one Lions' analyst who called for him to be taken out of the starting lineup. But over the last four games, since the bye week coincidentally or not, he has committed zero penalties.
The Lions were going to stick with Arnold through his early adjustment to how the NFL officiates cornerback play, with an eye on how much demand would be put on him to hold up in 1-on-1 coverage and not wanting him to lose his aggressiveness.
Davis has also had some issues with penalties this season, though four of his eight penalties came in one game (Week 4 against Seattle). More generally, Davis has brought an aggressive mentality to the cornerback room. Penalties are the price that's sometimes paid when you have corners who are actually near receivers in coverage.
Carlton Davis and Terrion Arnold have been top-notch in single coverage
Judah Fortgang of Pro Football Focus and Throw The Dam Ball charted how often cornerbacks have played in single coverage so far this season and their PFF separation grade on those plays (minimum 100 coverage snaps).
Arnold (No. 2) and Davis (No. 5) are top-five in single coverage rate among qualifying cornerbacks entering Week 10, each doing so north of 60 percent of the time. Amik Robertson is also above a 60 percent rate playing single coverage
On the separation grade scale, from -2 to +2, Davis and Arnold are both above average on their single coverage snaps along with the sheer volume of the time they play single coverage. Robertson is lower in separation grade, but hardly abysmal.
There's room to be better in some spots, but the level of cornerback play the Lions have gotten this season is noticeably better than it was a year ago.
