Iowa was more talented than Purdue, NW, Wisconsin, and pretty much everyone else of the schedule last year except for PSU and Iowa's starting 22 where probably better than PSU's. Yet Iowa lost all four of those games.
But performance in close games does not seem to be a consistent thing from year to year (in any sport). Typically, a team that had a horrible record in close games (e.g. 2018 Iowa) is no more likely to lose a close game in the next year than a team that had a great record in close games the prior year. Most teams come out at about 0.500 in close games over a long enough time span. There are exceptions (I think NW has been exceptional in close games for most of the Fitzgerald era), but they are rare.
Just look at recent Hawkeye history in one-score games:
2015: 5-1
2016: 3-3
2017: 3-3
2018: 2-4 (counting Wisc as one-score game due to meaningless late TD; Iowa started 0-4 in one-score games, ended 2-0 in their last 2 one-score games)
So there is nothing in that history that suggests that recent-vintage KF Iowa is likely to be worse than average in close games (
this article from prior to the 2015 season suggests that older KF Iowa may have been deficient in this area).
What is notable is that they had a great point-differential last year (
17th best in the nation), as well as a great points/drive differential (
22nd best in nation). They got hurt by horrendous punting, some terribly-timed blunders (Wisc punt return unit twice coughing up unforced turnovers; the PSU goal-line interception), some instances of getting outschemed (goalline vs. Wisc; NW, again; Purdue), and some bad luck (90th out of 130 in nation in fumble recovery % last year; this is a stat that seems pretty random from year to year, Iowa was 1st in the nation in 2016, 128th in 2017).
The punting has to improve (it can't get any worse). Odds are the fumble recovery % will be better. Blunders will happen, but the odds of them happening at the worst potential times again are low. We might be outschemed again, but hopefully the talent difference will be enough to make up for it.
I would be absolutely shocked if the Hawks were 7-5. That would be 2010-level collapse (okay, I shouldn't be that shocked, it has happened before). I just don't see it going down that way this year. Then again, my glasses are fully-tinted (black and gold), so perhaps I am just missing the obvious weaknesses.