To begin, I would like to say this is not just some Janoris Jenkins-is-terrible post. I feel horrible having to add that note, but lately providing any criticism of a player around here is seen as "hate." I think Janoris Jenkins will be one of the better CBs in football in time. He has all the physical tools that could be asked for and he is being coached very well by Chuck Cecil and has a great mentor in Cortland Finnegan.
The point of this post is to point out where Jenkins is struggling, why he is struggling there and what the Rams could do to help Janoris and the defense improve.
The great news for Rams fans is Jenkins problems are mental. His main issues in coverage do not stem from anything he is doing wrong physically or fundamentally (at least the physical fundamentals). Mental issues are much easier to correct that physical ones, because to correct physical mistakes, muscle memory must be un-learned and then relearned, which is a rather long and tricky process. Mental issues can be solved more easily, such as simplifying the game, which is what I suggest Janoris Jenkins should do.
Here's a GIF of where Jenkins struggles. Props to Ryan for getting to to me, I know it was rather annoying to do.
This play was a third and three that the 49ers completed easily. The play is a delayed slant to Mario Manningham. Jenkins is lined up close to Manningham, but he doesn't press him. Manningham then uses stutter steps to freeze Jenkins before breaking off for a easy first down.
After watching this many times, it's easy to see that Janoris Jenkins is caught flat footed, something that has happened far too often for the rookie. A cornerback will lose the battle every single time this happens. Janoris also falls for a very simple double move as he bit on Manningham's first move.
What should have happened on this play is Jenkins should have played Manningham even tighter and pressed him off the snap, or Jenkins should have be moving backwards looking to break on the ball when it was thrown.
In this instance, it seems Jenkins is worried about too many things. He is worried about the short pass, which is why he is lined up tight, but he is also worried about getting beat deep, which is why he didn't challenge Manningham's release.
One of the greatest military strategist Napoleon said "If you defend everywhere, you defend nowhere." Jenkins was worried about two things at once and was thinking far too much on this play. This led to an easy first down for the 49ers but it could have been worse. Manningham easily could have broken his route up the field for a big play.
He either needs to decide to challenge Mario on the snap or to back off and the snap and look to break the route. You can't do both, or you will be embarassed like Janoris was here.
On each play Janoris needs to only have one thought in his mind. In this case it's either, challenge the receiver and deny him the inside, or back off the WR and look to break on the route. Better to do one assignment very well on a play, then to do two or thing assignments poorly. Keep it simple and you will find more success and more awesome plays like this.