I find it interesting people refer to Cally/ Cosgrove when Bo/ JP was just awful yet almost forgotten.
I don't believe that Bo was a bad defensive coach. He did pretty well in the Big 12 when he had Callahan talent. He was a pathetic recruiter and it caught up to him.
His team was also not well suited for the change from mostly wide open passing spread offenses of the big 12...compared to more pro style-power rushing teams in the Big 10.
Not to mention, he couldn't have been too bad. He was one of the most successful head coaches in the country while he was here.