at first one is tempted to just say Moorer...……..after all, he was Heavyweight Champion. however, at light Heavyweight, we have absolutely no clue how good Moorers chin would have been. yes, he was wbo Champion...…...but back in the day when the wbo wasnt a serious world title belt. it´s more like Holding the ibo Crown nowdays. anyway, Moorer never had a great chin at Heavyweight......so what does it say for his chin at light heavy?? would it have been better cause the opponents were smaller? or would he have had to starve himself to make light heavy......meaning his chin would have been even worse. i would say Moorer…...but not with great certainty