Watch the MLB on this play:

https://private75.myfootballnow.com/watch/1697#316659

He's assigned coverage of WR5. The RB however stays in to block, so there are only four coverage assignments. As a consequence he effectively becomes a 'dead' player and stands there doing absolutely nothing. This is silly. Players in the NFL don't sit and pick daisies if their guy stays in to block. In this formation the LB is assigned the RB. According to JDB defensive players without an assignment are supposed to 'shadow' their player. However, the MLB drifts sideways away from where the RB chooses to engage his block and then proceeds to remain static, even after the ball is thrown.

As soon as the MLB diagnoses that the RB is staying home, he should "soft" blitz to engage the RB. Which is to say, he should blitz as if attacking the QB, but specifically target wherever the RB is (and the RB should be "home" which is addressed in another suggestion post I just made) and engage him in a block. This is to stop the RB from being able to chip someone else as well as prevent him from peeling off to the flat for a dump off, not to mention positioning the LB to take advantage of an opportunity to get a sack if the QB happens to get flushed. At worst, if the MLB reacts too late to effectively soft blitz, or is too far off the line, he should at least move forward to shadow the RB at or close to the LOS.

While this isn't a massive issue since HBs don't effectively move into the flat as of now, it would be really great to at least start getting the pieces into place to start building off of (because if RBs/FBs did get fixed to go into the flat for dump-offs defenses would start getting absolutely destroyed when not blitzing 6). Not to mention just for aesthetic purposes, because it looks really absurd for a guy to just sit twirling like an idiot in the center of the field.