The defense may not have to be Clemson/Bama/Georgia-good, just better, as long as the offense can play at a high level. Had OU had even a mediocre defense--instead of a bad one--in 2017, the Sooners would have beaten Georgia in the Rose Bowl and gone on to play Bama in the NCG.
The tackling was definitely better. If that's our only improvement, then we're better than last year.
We got a red-zone takeaway that was called back. I didn't see the replay, so I can't comment on the call.
The catch out of bounds that got ruled a Houston completion was IMO a bad call that wasn't clearly bad enough for the replay official to overturn.
The PF on Fields on the play after he was called for DPI was, IMO, ticky-tack. The Houston receiver initiated it.
Had any one of those calls gone our way, we would have held them to 24 points and be feeling a bit better about the defensive performance.
In a way, I'm glad those calls didn't go our way, as the 31 points allowed (in a win) gives Alex Grinch more ammunition with which to motivate the troops to do better next time, and the time after that, and so on.
I think the defense will be a work in progress. I think it will be much better than last year (a low bar to clear) by the second half of the season.