1) There is a huge gap in qb talent between Book and probably every other team ranked through at least UCF. I haven't seen much of the next 5 teams after that but I would suspect that Book wouldn't be starting for any of those teams either. Heck there is a huge talent gap on his own team. Book certainly should have been starting qb over Wimbush but it isn't as if he earned it as much as Wimbush, for whatever reason, never was able to harness his much better physical talent that Book into learning how to play the position. Book is easy to defend for any quality DC and he has to be perfect to be able to beat elite teams. That is hard to do for any qb to do. It will be interesting to see if Book can get any better. Kelly's track record with QBs (Golson, Kizer, Zaire, Wimbush) indicate he doesn't know his ass from his foot re: developing qbs. If we are merely lucky, Book will not digress as other Kelly qbs have in the 2nd years of starting. If he doesn't improve, a quick peek at the 2019 schedule sees 4 games that will be tough to win and you can see the obligatory 2 games we will struggle to win.
2) Whatever Book can or cannot do as a QB (few qbs are ideal), he is hindered by a his 2nd class offensive scheme (and yes this is Kelly's offense ) and a lack of "suddenness" at WR. Book is easy to defend for elite teams because they can press our wrs and dare Book to beat them deep. The lack of any semblance of misdirection as well as the absence of quick short distance speed at WR is a killer equation for a qb with Book's ability. Throwing the ball high and hoping for your big tall receivers to win jump balls and drawn-out running plays to the flanks is not a recipe for success against elite teams as we clearly have demonstrated no matter who the qb is.
3) Our defense on given years is probably good enough to allow us to compete for titles if our offense can compete for titles. But we will lose at least our 4 best players on defense --Tranquill, Coney, Love, Tillery off the top of my head. Do we have the players to merely replace them much less be a better defense? Heck this is the problem many college programs face but I fear that it will take a perfect storm for the quality of both squads to allow us to really compete for the title.
4) Kelly is not an elite coach. Time after time, he gets outcoached in big games, seemingly unable to comprehend that the same-old, same-old approaches that result in overly close games with average opponents or versus good coaches don't work. See any new wrinkles for the Clemson game? Kelly is incapable of new wrinkles, particularly on offense.
It wasn't that fact that we lost that bugs me it is the nature of the loss that bugs me. Has Kelly really progressed as a coach since 2012? Everyone understands that there is a class system in college football with Alabama, Clemson, Georgia and Ohio State as elites, a group of 10-15 schools (including ND) as pretenders that can sneak into Elite status in a given year but aren't going to be there every year and everyone else. I have always enjoyed going to ND games but I suspect once I get past 2020 and ND vs Wisconsin in Lambeau, I will still be a loyal son but won't be going to any games if this the present is the future. To quote an often used movie line: " I'm getting too old for this shit."