On the TCU run defense, I just didn't see much to give me a lot of pause. For every play where there were errors and breakdowns there were others in which their DL made some plays, the linebackers flashed athleticism, or the safeties ran guys down on the perimeter.
For instance, here's TCU struggling with "power" from the Jackrabbits.
You see the Jackrabbit RB nail the cutback lane left open by the pulling guard and TCU doesn't fill it very aggressively, leading to some nice space.
Here's how the play was supposed to work for TCU:
As you saw on the clip though, weakside safety Nick Orr was late to fill that assignment and since the Jackrabbits stacked up the strong side of their formation to the boundary the RB had a LOT of space to work in when he cleared the first level.
Later on that drive, the Jackrabbits ran power again:
This time the Jackrabbits get into a similar formation where the strength is loaded into the boundary again via motion. Nose tackle Joseph Broadnax doesn't get over into the new A-gap properly this time, perhaps because he's wary of giving up the cutback. Field cornerback Ranthony Texada and weak safety Nick Orr both rush to fill that cutback lane in the B-gap this time and get too deep to recover when the RB instead plunges into the A-gap.
What you're seeing here isn't really a failure in which players are being over-matched or unable to fulfill their assignments though. It's just missed assignments and mental busts that lead to costly mistakes.
I'm very confident that Gary Patterson can clean that up, and indeed the following week they were fairly solid against the Arkansas run game. The cornerback issues in coverage I broke down at Football Study Hall on the other hand...those might be bigger issues that linger into the season.