I wasted "some" time since I was curious.
Iowa and ISU held all major opponents below their avg except for two times. (ISU let OSU and KSU, and Iowa allowed PSU and Minnesota score more)
Iowa was the 8th best scoring defense which was second in the Big 10 behind 5th MSU.
ISU was the 30th best scoring defense which was top in the Big 12.
Big 12 Avg rank of scoring defenses: 70th
Big 10 Avg rank of scoring defenses: 53rd
ISU played the 1st, 10th, 14th, 16th, 24th, 36th, 39th, 68th, 95th, 108th, and 111th Best scoring teams. (Avg 47th best scoring teams)
Iowa played the 23rd, 40th, 47th, 52nd, 54th, 57th, 75th, 77th, 80th, 84th, 92nd Best scoring teams. (Avg 61st best scoring teams)
ISU gave up 22.8/game against an average scoring offense 47th, with a high of 1st and low of 111th.
Iowa gave up 18.1/game against an average scoring offense 61st, with a high of 23rd and low of 92nd.
ISU ranked 30th in scoring defense against a higher scoring conference and bowl opponent. Iowa ranked 8th against a lower scoring conference and bowl opponent.
ISU kept opponents a total of 88.9 points below their avg across their 11 major games.
Iowa kept opponents a total of 98.4 points below their avg across their 11 major games and
Head-to-head:
Iowa kept 75th best scoring team, ISU, 23.8 points below their avg in the first game of the season.
ISU kept 39th best scoring team, Iowa, 17.6 points below their avg in their second game of the season.
Was ISU as good as Iowa defensively? Not in scoring defense without the weight of their opponents played. Was ISU a good defense? I think it's safe to say they were very good.
(Here are the scoring defenses ranked:
5th - Michigan State
8th - Iowa
14th - Michigan
18th -
Penn State
27th - Wisconsin
30th - Iowa State
35th - Northwestern
42nd - TCU
46th - Ohio State
48th - Kansas St
49th - Texas
55th - Minnesota
67th - W Virginia
73rd - Maryland
79th - Indiana
80th - Purdue
82nd - Kansas
84th - Rutgers
88th - Baylor
94th - Nebraska
95th - Oklahoma
98th - Oklahoma St
99th - Texas Tech
126th - Illinois)
Here are the scoring averages for the two teams, bolded are the teams ISU played:
1 - Oklahoma
10 - W Virginia
14 - Oklahoma St
16 - Wash State
23 - Penn State
24 - Texas Tech
36 - Texas
39 - Iowa
40 - Purdue
47 - Wisconsin
52 - Minnesota
54 - Nebraska
57 - Maryland
68 - Baylor
75 - Iowa State
77 - Indiana
80 - Miss State
84 - Illinois
92 - Northwestern
95 - Kansas
108 - Kansas St
111 - TCU