I see Jacobs challenging GGG for a while. Thing is, in addition to his power, GGG has very good technical skills - he just doesn't often feel compelled to use them. A fight where he did was against David Lemieux. But he is an Olympic Silver medalist from a country without much of an amateur boxing program.

Jacobs has power and technique. I think eventually he will get worn down but it should be compelling getting there.

As far as GGG-Canelo, I actually see Jacobs being more of a challenge. The only thing Canelo has over Jacobs and possibly GGG is his chin. Granted, that is a big factor but it won't be enough vs GGG so long as GGG sticks to a disciplined game plan.