Duke’s 2018 defense was pretty good. Not great, but pretty good. Especially the back end.
Some stats for the Blue Devils:
29th nationally in pressure rate (33.9%)
20th in completion% allowed
48th in QBR
33rd in passer rating
21st in yards/attempt
41st in TD/attempt allowed
In case those numbers don’t appear particularly striking, here’s the list of teams that exceeded them in 2018: Penn State, Miami, Southern Miss and LSU. That’s it.
So, given all that context, here’s the number that really stood out: Four.
That’s Duke interception total last season. Four. Only Oregon State (3) finished with fewer.
We’ve talked a lot about turnover luck, but there are things teams can do to tilt the odds in their favor. Forcing more passing attempts. Getting pressure up front. Putting teams in third-and-long.
Thing is, Duke did all that at a reasonable clip. Again, nothing extraordinary, but certainly well enough you’d assume even bad luck would’ve resulted in a bunch more INTs.
There’s really not a ton of historical precedent. In the past decade, Duke’s rate of 1 interception per 47.25 incompletions is the sixth-worst among all Power 5 defenses.
But here’s the good news for Duke. We looked at every team from the past decade that averaged at least 30 incompletions for every 1 interception, and their follow-up campaigns showed that the luck really did even out.
For what it’s worth, it’s a short list. 29 teams in 10 years, with five of those happening in 2018. Why is it more frequent lately than a decade ago? Your guess is as good as mine.
The other thing of note is that there aren’t a ton of good teams on this list. Yes, a lack of turnovers likely correlates with a lack of wins, but also the other way around. Turnover rates go way up when a team is trailing, so if this group wasn’t leading many games, the opposition wasn’t as likely to take risks.
It’s worth noting that defenses that are challenged deep more often are just as prevalent in this list as ones who weren’t. Less than half the passes that 2012 Virginia team defended were thrown more than 5 yards beyond the line of scrimmage, while 2016 Texas Tech defended 67 percent of its pass attempts beyond 5 yards. So while you might point to Duke’s stellar linebacking crew in 2018 as a reason teams avoided risky throws over the middle, there’s not really a precedent that suggests that’s reason for the low INT numbers.
But more than anything, what this data should tell you is that things will change this year. On average, the teams in this data set nearly tripled their INT totals in their follow-up campaign. Of the 24 teams, 21 at least doubled their output. Teams like 2010 Michigan State and 2018 Syracuse went from being among the worst at getting INTs to among the best in just one year.
Will that happen for Duke? There’s reason for optimism beyond this historical precedent. Michael Carter established himself as an exceptional corner last year. Marquis Waters and Josh Blackwell got valuable experience as freshmen. Brandon Feamster returns, too. The young unit that had its ups and downs in 2018 should take a nice step forward in 2019, and this time around, luck should be on their side.