Derevyanchenko. Why? He fought GGG at his oldest age.
Not only age, but mainly poor condition due to the illness. Those factors combined made Derevo look the best against GGG. He fought the version of Golovkin which was available. Couldn't fight imaginary prime GGG.
I’d like Golovkin to give him a rematch. I believe it’s deserved. However ggg took a serious amount of punishment which is not good for his long term health.