These two bits seem in contrast to each other... Was there a coaching or schematic change that would make previously-productive players suddenly not productive?
Last year's DL coach took another job. The DL coach Kelly hired had some medical thing that forced him to quit shortly before the season. A guy who has never coached DL was promoted to the spot. That's the only thing I know of on the coaching front. Still, when you see dropoff like this, you know it has to be coaching.
House was not impressive as a DC last year, but he wasn't awful either. Biggest glaring weakness is he has no idea what to do with linebackers. There doesn't seem to be a defined plan for them. They're listless and mostly react to plays once the blocking has already been set and they're caught in the wash. The one bright spot there was a LB who was a human scud missile sacking and spying QBs. He's elite at it. What has House had him doing this year, mostly? Dropping back into coverage in a futile effort to help a pitiful secondary, while the line generates less than zero pass rush. The secondary sucks anyway, an extra LB hasn't been helping. It should be obvious to keep him near the line and at least apply some QB pressure.
Apparently combining a listless defensive gameplan with languishing line technique is a poor recipe.
Usually when something is this bad it's not just one thing. Indeed,
some of the secondary's problems is a talent deficiency. We've seen a lot of guys in the front 7's two-deep be quite good either here or at other schools the last couple of years. They never look like they're playing as a unit, like they know what the scheme on any given play is supposed to accomplish, so sometimes you get different guys making individually impressive plays, but to no discernible end. Most of the time they just suck, as described above.
I didn't think it was possible for LSU to rank 120 out of 130 in yards per play allowed, but there you have it. Bright side is since I last checked Vanderbilt has overtaken us as the worst D in the conference, so at least we're not on the bottom anymore......yay?