DB group as a whole did rate pretty poorly ranking 126th in the nation in DB Havoc rating (percentage of plays where DB either had TFL, forced fumble, pass deflection, or INT). Pass efficiency defense rated 105th in the nation which is pretty bad. S&P+ Defense rating was a little better at 72nd in the nation. I agree that probably the biggest contributor to that was the lack of a pass rush which gave the QB all day to find the open receiver. CBs also performed better than safety's. However, for numbers to be just as bad as they were there has to have been at least some issues at CB as well (and I know there were injury issues which also helps explain things).