There was also a fair amount of attrition, primarily due to injuries but also a couple of transfers. Several factors contributed to the decline in the OL.I can promise you it’s not.
Doyle was there from 2011-2014 when Iowa went 26-25. OL play has not been dominant or good since the 2000s.
Yes, the OL has been trash since Doyle left, but correlation doesn’t mean causation. The truth is Iowa has put out a bunch of guys (like Plumb) who have no business being on a P5 roster let alone starting. I would also add OL really began regressing after Brian Ferentz stopped being the OL coach. When you factor in how much stronger and faster the defense has been since Doyle left, I don’t think there’s any real cause and effect here as it relates to Doyle.
Yes, Doyle was good. That doesn’t mean S&C completely went to shit after he left. The truth is there have been too many awful weak links on the OL forced into the starting lineup while being taught by a coach (Barnett) whom I am still perplexed by in terms of why he still has a job at the University of Iowa.