First of all I would like to say before Whitebeard in marine ford arc fought Blackbeard he had injures from other battles like Akainu injures and others Blackbeard needed his whole crew to fight a injured stage 50 cancer 70+ year old man on life support during the fight Blackbeard with his crew actually lost but Whitebeard kept the fight going and spared him leading to Whitebeards death and Blackbeard himself stated that he was scared or wouldn’t have fought Whitebeard in his prime and due to blackbeards inexperience and the just gap difference and the fact that prime whitebeard could tie with Roger without even using his devil fruit ima have to give this one to prime Whitebeard also correct me if I’m wrong