Yeah, I've been posting a points per drive stat on here for a few years and have regularly made the point about the use of per drive, per play and per game stats. I hardly need you to tell me to listen to CPJ on the topic.
The point with the use of any statistic is to understand its strength and weaknesses. If you want to discuss ranking of various teams against each, then efficiency stats like points/drive and yards/play is better than per game stats due to the significant variability in number of drives and number of plays per game currently. However, if you want to assess the strength of a defense against the pass, then you want to look at more than just one stat. If defensive pressure is decreasing the number of pass plays and increasing the number of sacks, then perhaps yards/attempt goes up for some teams. Moreover, if you want to assess the quality of a coach, then you don't look at one game or one season but a series of games/seasons.
I agree with all of that and you are correct when you challenged my use of ONLY yards/attempt when evaluating a pass defense. However, I think it does the job just fine when we are talking about a big difference. Michigan State's 2013 defense gave up 5.2 yards/attempt and Pitt's 2016 pass defense gives up 8.5. One is a very good pass defense and one is very bad, both coached by Pat Narduzzi. No further analysis needed. With Duke, I was trying to compare its 2014 pass defense against its 2015/2016 pass defenses. I wasn't trying to compare the 2015 and 2016 groups because they are pretty similar (both bad) units and, you are correct, one single stat won't do the analysis justice.
I included the statistics for people who may not be as familiar with the non-GT defenses. But the stats weren't really necessary for these comparisons:
Narduzzi's MSU defenses>>>>>>>>>>>>>>>Narduzzi's Pitt defenses
Wommack's Ole Miss defenses>>>>>>>>>>>Wommack's GT defenses
Auburn's 2016 defense>>>>>>>>>>>>>>>>>Auburn's 2015 defense
Duke's 2014 defense>>>>>>>>>>>>>>>>>>Duke's 2015/2016 defense
The main difference between these teams: PLAYERS. It's not the opponents, the DL coach, the schemes, etc.
The whole point was to prove that talent matters way more than the DC. If you asked me if I would rather have 2 first round defensive talents on this team, or a "first round" caliber DC (like Narduzzi or Muschamp), then I would definitely take the players.
If Roof wasn't showing improvement in recruiting over Groh and Wommack, then I'd say fire him! But he is. I believe we could do a better job at developing our talent as well, but I hold the positional coaches more accountable for that (maybe some former players could correct me here). I think Torrian Gray (VT DB coach) has had a huge impact on Bud Foster's success. And just as I judge Roof, I think we should fire the positional coaches UNLESS they are doing work on the recruiting trail. Only CPJ and Roof know the answer to that.