Great fighters don't just step in with every jab. They set it up, they time it. Spence does it with every jab(at least used to). So when one is squared up with him, and they see him step in, it's most likely that he is jabbing. That is the flaw. His set up to the jab is poor, but his use of the lead hand otherwise is solid. He know how to probe, how to control the opponents lead hand, how to occupy the space between him and his opponent. It's just the damn step. Brook countered the **** out of him at times. No idea if Spence fixed the flaw or at least knows to adapt now if someone counters him again. Ocampo and Peterson didn't test him.