Cannavaro didn't had Barzagli's consistency bro. When was the last time Barzagli had a bad game? Or missed a game due injury? The class and how he always looks like he is in full control is exceptional and makes Thiago Silva mediocre.
If he keeps performing like he has been doing in the past two season I'll even say he should go down in the Italian history books as one of the very best.