i think its because RJJ carried himself the best through his weight jumps, when he fought ruiz at his campaign at HW, he was still fast as lightining, hit hard, and still had good stamina. he didn't look any different performance wise at HW then he did at MW. thomas hearns was successful at his weight jumps, but didn't look any where near as impressive at lightheavy then he did at welter. hearns best performances were at welter up to middle.