exactly..CroCop at the end of 2006 was a beast. But since he's been knocked out by Gonzaga, dominated by Kongo, picked apart JDS, KO'd by Frank Mir, outstruck by Pat Barry, and KO'd by Schaub.
Chuck Liddell, although overrated, also was a pretty damn good fighter back at the end of 06 before getting brutally knocked out half a dozen times since then.
Barnett, however, is still the same elite fighter he was 5 years ago due to fighting nothing but cans. He hasn't been knocked out a million times in the last 5 years. He may be even better. If you didn't think Barnett was elite 5 years ago, you've been living under a rock.