Finally got around to watch GGG-Brook. And it seems that "GGG was struggling" is greatly exaggerated. People tend to listen more than watch themselves. Paulie says that GGG does not move his head and this is a gospel now. Only God is infallable, while Paulie could be caught up in the conversation and miss some stuff. GGG sees incoming punch and if he can't get out of the way, nods and takes it on the forehead. This is as "old school" as it gets. Which is why Brook was not too eager to throw straight with force after a while, out of fear to hurt his hands. He did throw, but only scoring punches, with not a lot of sting behind. Of course the medicine against it is the uppercut. And Brook quickly realised that, because he is a smart technician himself. But the problem - he was going backwards all the time. His uppercuts were also just scoring punches. It is harder to hurt an oppenent, when you are going backwards and not given an option to plant your feet. All-in-all I would not straight away discount Brook against other less skilled middleweight.