Some of it is scheme, take against Michigan , You have Iowa's less athletic OL , trying to zone and trap block a DL that is quicker and have better first steps, That is not a good recipe for success , Iowa rarely Man blocks but that is how You minimize that disadvantage, You get a hat on the DL and your uncovered OL get the double team at thE point of attack and try to get the LB with the TE and and FB , Wisconsin made a living doing this , Iowa for Years has allowed penetration and because of the lack of deep threats are also running into 8/9 Man fronts where the OL is just outnumbered. SCHEME SCHEME SCHEME .