I think what we all overlooked with Kelvin dropping to 170 was how much of his game is based around being a faster and more dynamic athlete than his competition.
At MW even though he looked chubby he had shocking quick hands and foot-speed relative to most of the division, and his incredible chin and block head let him eat shots from bigger men so that he could implement his attacks.
But at WW he appears drained of energy and confidence, on top of having his speed advantage completely negated. Pretty sad seeing him motivated to lose the weight but unable to implement any realistic game plan.