Sophomore slump, it's a thing for a couple of reasons.
Also we played off a lot more today, I barely saw any bump n run coverage and IMHO that could have had something to do with Burnett's absense.
Burnett's absence was part of it. The bigger factor was trying to defend the run while playing nickel all day. Lots of single coverage on the perimeter yesterday which is why you did not see much press coverage.
Randall "looked" terrific early in his rookie season because, inexplicably, opponents didn't throw at him in the first 3 or 4 games. After the game saver against San Diego in week 6 there has been a steady slide.
You know, Randall played just a little CB in college, and it wasn't because he was especially good at...it was because the guy he replaced was clueless, which is saying something against college competition. He's had to learn corner technique on the job in the NFL. That's no easy task. The injuries have not been helpful. He overplays his outside technique and gets beat underneath; he overplays inside technique and gets turned around. He's susceptible to double moves. He's not trusted to use press technique one-on-one unless they play for the jail break blitz and the quick throw blitz read by the QB. The default cover up is playing him off into a backpedal leaving a lot of separation.
There's also the question of whether he's got a grasp of the defensive "scheme" as it were. I put "scheme" in quotes because it's not as though you would expect top side help coming out of the huddle, but at times would expect it based on the post snap read where instincts meet practice and study. Call it "chemistry". When Randall gets beat over the top, he invariably expresses complaint at not getting the top side help. While sometimes that may well be Dix's fault, hanging around in the middle of the field looking for work, but you'd have to think that's on Randall in most cases.
He's got the talent and he'll eventually be a respectable perimeter corner if he can stay on the field by dint of health and tolerable performance. Study and practice is all fine and good. But there is simply no substitute for learning in real game situations. That's a very big part of "draft and develop". The develop doesn't happen unless the guy can get snaps and build on them (see Brice as an example). Randall is getting a lot of rope because he's a first round pick and because of the injuries. For now, he needs to prevent giving up the big play, and that may be enough if the offense keeps rolling.
I've said it many times and I'll say it again: his natural position is old school ball hawking free safety. Some claim he's not physical enough for the position. That would be the case if you're inclined to alternate your safeties coming up in the box as Capers does or you count on your free safety to intimidate as with Earl Thomas. KC doesn't play that way; Eric Berry is not a particularly physical guy. Same deal with Jarius Byrd in Buffalo before he was injured. Even Dix doesn't blow guys up; he's pretty much an ankle biter in the open field.
I gave this pick a D grade at the time it was made. Not because Randall's a bad player. It's because you can't afford to wait around for 5 years (as with Perry) to see him earn his draft status after a change of position. But that's water under the bridge and a question for the offseason.
Right now, just keep outscoring them, baby!