I agree that Chester has been below par compared to last season when Terry organised him. However he's not had a consistent partner, had a midfield leaking runners and no organisation from management.
Jedinak on the other hand is not a centre half. He's a liability there. So I find it very easy to argue that its ridiculous to say Jefinsk is no worse than Chester. Watch how many times Smith plays Jedi at the back. Im guessing not at all.