He was used to dominating his opponents until he made a crucial mistake of shedding down from HW to LHW in a short amount of time to face Tarver and when he got knocked out in the rematch, his confidence and his aura of invincibility was totally shattered into million pieces.. That KO didnt take much from him, physically, but it really messed him up mentally and he went downhill from that point..

He's still greater than Hopkins imo..