Everyone knows Iowa is a developmental program, but does returning production mean a better team? We’ll tackle each aspect of football over the next few weeks in an attempt to see how last year’s stats might impact this year’s team. Next up: defense.

All stats were gathered using sports-reference.com/cfb unless otherwise noted

Previously: Special Teams & Offense

Interceptions

Iowa loses an all-timer in Desmond King. But his production last year, in terms of simple interceptions, was not what it was in 2015. For perspective, Iowa only had one more as a team in 2016 than King had in 2015. That’s nuts. If Iowa had not lost Brandon Snyder to injury, they would have brought back six of last year’s nine interceptions. Instead, they’ll bring back only three (Manny Rugamba had two, while Ben Niemann had one).

Also, interceptions is the only stat which goes back to 2000! So, there is a smaller data set for the remaining stats (2006).

Interceptions Returning

• 0 - 33%: 5.7 wins, 24.9 opponent points
• 33 - 67%: 8.1 wins, 18.5 opponent points
• 67 - 100%: 8.7 wins, 19.2 opponent points

Iowa dodges an arbitrary bullet, as 3/9 = 33.3...% so they’ll fall into the second band (and would have had Snyder’s picks have counted as well). It’s also interesting to note previous seasons which 2017 might follow are much different than what returns for this season. Specifically, the transition between 2013 and 2014 saw Iowa’s senior troika of James Morris, Anthony Hitchens, and Christian Kirksey depart with six of the defense’s 13 interceptions while BJ Lowery and Tanner Miller had three apiece before graduating.

2017 faces no such departures in the linebacking corps - though 2018 will - and for that, Hawkeye fans should be thankful. 2013 also mirrors 2016, as Manny Rugamba is already ahead of King in terms of their interception total, though freshman King lapped freshman Rugamba in tackles (69 to 19). Rugamba still has a long way before his career can be compared to King’s, but at this point, his ballhawking skills are something to watch, and perhaps rely on, this coming season.

Sacks

Thankfully, Iowa faces no such drop off regarding sack production. The only sacks which are gone are those who went to the Twin Cities with Jaleel Johnson. It was still a significant amount - 7.5 - but there are plenty of guys on the roster who recorded one in 2016, including 17 along the defensive line.

Sacks Returning

• 0 - 33%: 4.0 wins, 22.9 opponent points
• 33 - 67%: 8.5 wins, 20.1 opponent points
• 67 - 100%: 7.8 wins, 18.0 opponent points

The Hawks return the exact same amount of sacks as last year, but with the departures of Cole Fisher, Drew Ott (who Kirk Ferentz and most Hawkeye fans still believe should have gotten a fifth year) and Nate Meier, it meant a lower percentage than the 72% for this year. Looking at 2006, Iowa returned 76% of their sacks with a young core in Brian Mattison, Kenny Iwebema, Mitch King, and Matt Kroul.

Those four went on to increase their cumulative sack total from 14 in 2005 to 17 in 2006 and 2007 with Mattison notching 9 alone in the later year. A similar jump out of Nathan Bazata, Parker Hesse, Anthony Nelson, and Matt Nelson (no relation), Parker Hesse, and Nathan Bazata (to say nothing of Cedrick Lattimore and incoming freshman AJ Epenesa) would help shorten opponents pass clock to fill the holes in pass coverage left by Greg Mabin, King, and the injured Brandon Snyder.

Tackles for Loss

It’s no real surprise that tackles for loss follows a similar trajectory to sacks, as both are often accumulated by defensive linemen in Iowa’s scheme. The team-high 10 from the departed Johnson are followed in short order by 8 for Big Ant, 7.5 by Hesse, and 6 a piece for Josey Jewell and Matt. In total, 66% of Iowa’s tackles for loss will return in 2017.

Tackles for Loss Returning

• 0 - 33%: 4.0 wins, 22.9 opponent points
• 33 - 67%: 8.6 wins, 19.7 opponent points
• 67 - 100%: 7.3 wins, 18.2 opponent points

On the whole, Iowa normally has defensive linemen post the highest number of tackles for loss. 2013 offers an vision of how 2017 might turn out, as linebackers James Morris and Anthony Hitchens led the team with 17 and 13.5 respectively. Christian Kirksey added five more for fifth on the team.

If the offense struggles to sustain drives, it will be imperative for the guys in the trenches to rotate consistently. I expect Iowa to go at least six deep, and perhaps as far as eight with Brady Reiff and Chauncey Golston in the mix. Jaleel was a man possessed at times, but struggled with consistent effort throughout his tenure. Relying on more well-rested guys to maintain contact with blockers would open up lanes for Bo Bower, Ben Niemann, and Jewell to get into the backfield to break up plays.

Tackles

Josey Jewell leads the charge, returning 124 tackles with Bo Bower behind at 91. The departures of Snyder (85), King (58*), Johnson (56), and Faith Ekakitie (39), among others, mean we’ll see 64% of Iowa’s tackles to return.

*An aside about King’s tackle numbers: 58 was his career low which is shocking considering he totaled 69 in his freshman year. QBs were definitely not throwing his way.

Tackles for Loss Returning

• 0 - 33%: No applicable seasons
• 33 - 67%: 7.4 wins, 20.5 opponent points
• 67 - 100%: 9.0 wins, 17.1 opponent points

The loss of Brandon Snyder is never more apparent than it is here. With his 85 tackles no longer there, it drops Iowa from 74% returning to 64%. He improved drastically over the last year as he focused less on making the big hit and more on sound tackling. He’ll be missed as the last line of defense while Jake Gervase comes up to speed.

The 64% is, however, the most returning tackles since the 2013 season mentioned above. It’s hard not to draw parallels to their defense, with 3 returning senior starters at linebacker. When Jewell eschewed the opportunity to go pro early, he gave this defense a man in the middle to rely upon. If the line can hold their ground, I expect an individual season to remember for Jewell.

Overall

The number to remember here is 20. When Iowa holds teams under that number, they average 8 wins a game. When it’s less, they average 6.5. And when it’s 20 exactly, it’s 7 (2005).

Perhaps the most exciting thing for me with this graph is the slow trending build in the lines from onward 2014 for tackles, tackles for loss, and sacks. In each of those seasons, the defense has improved on a points per game basis (though wins haven’t necessarily followed). For 2017, I expect the offense to need more than a couple “give us 14” games.

Hopefully the defense can comply.