I certainly give Coach Brian Kelly credit for making some much-needed changes to the program, beginning with last year.
The biggest impacts were at the DC and S&C coaching positions, without a doubt.
Hiring Mike Elko brought some sanity and stability to the defense, even if we did get badly exposed at the end of 2017. The bigger bonus was Elko bringing along Clark Lea with him.
This year, Lea has shown that he has a decent head on his shoulders. We never got into panic / desperation mode on defense, and we've been pretty consistent (and consistently good) throughout the year. Even when some of our guys went down, the backups who came in played adequately. It wasn't like the 2014 year, where losing a starter (Joe Schmidt) ended up in the whole defense falling apart.
Also, our guys on defense didn't tire out, despite being on the short end of the time of possession for most games. Also, this year seems to have had far fewer injuries than what we were seeing from 2014-2016. That last part can't be ignored at all, since Coach Balis seems to have our guys in much better physical condition than Longo ever did.
Hiring Brian Polian as a ST coach and recruiting coordinator was an overall net positive. He's a very good recruiter, and knows how to bring people in. As a ST coach, he wasn't great, but at least he was a good step above the disaster that Scott Booker was in 2016 (special teams cost us at least 3, maybe 4, wins, and could have easily cost us the Miami game). There were a lot of fundamental mistakes made this year, and ones that ended up making games that we should have put away early, into a real contest.
Hiring Chip Long is a nice positive, that we're actually utilizing our running game, even using simple plays such as the QB sneak under center, or a two back running play. Also, his style seems to mesh very well with Ian Book's abilities (not so much with Wimbush's, unfortunately).
His weaknesses got exposed during the first 7 years, no doubt.
He made several terrible mistakes along the way that cost us several opportunities. Using Paul Longo as a S&C coach (who wasn't even really there mentally in 2016) didn't rear its ugly head until about 2013-2014. As mediocre as Ruben Mendoza was during the Weis era, he did have several good points that covered up the holes in Longo's program. Kelly's stubborn refusal to even consider someone else at the S&C position (out of loyalty towards Longo) ended up killing us in 2013-2016.
Hiring and sticking with Brian Van Gorder, well, every person here can make his own conclusions about that clusterfuck of a hire. He had all of that NFL-level talent available to him, and it certainly got pissed away.
Finally, Kelly's playcalling wasn't exactly that spectacular, and thankfully, he relinquished control of that over to Chip Long. He should have handed that responsibility to the OC a long time ago.
All in all? I do believe that Brian Kelly has finally evolved as a head coach. He finally realized that his hard-nosed approach of "my way or the highway, and if you don't believe in my methods, then you can go to Hell" wasn't going to work very well at ND. While it was fine at Grand Valley State and Cincy, those places had much lower stakes, and a much more patient fan base.
I'm actually surprised that the ND fan base (and Board of Trustees) was this patient with him. After several 5 loss seasons, along with that 4 win season, the rumblings were certainly there.