Ferentz probably only has to win four/maybe five games to keep his job. His sweat would be really hot, but I can't see him getting fired unless he wins 3 or less games.
Ferentz is under ZERO pressure this year. The guy hasn't finished below .500 in the conference since 2006 and went to an Orange Bowl in 2009. The idea that Kirk Ferentz (and his 3.5 million dollar salary through 2020) has less job security than Jerry Kill (as was suggested in this thread) is laughable. What he's done at IOWA is incredible and he will likely be able to name his departure date.