They didn't duel. The Revenge attacked the Pearl and Bossa called for his men to abandon ship. But before they could the ropes of the Pearl tied everyone up. Bossa cut his own leg off to escape. There was never a direct encounter between the two til the end of 4
We don't know what happened but logically since his crew was defeated by Blackbeard we can assume he saw his skill level. Blackbeard did go back and forth with Barbossa even despite you arguing like crazy for him. Blackbeard overtook his ship and in their second encounter he knew he needed to cheat which implies inferiority. Abc logic is worthless when we have a direct comparison.
His crew was tied up just like him. There is no indication that any sword fight took place. Basically the Revenge fired upon the Pearl and then before the crew could abandon ship they got tied up. Not skill was shown. You are making a very large assumption based on nothing at all.
You don't know. You are assuming something like you watched a hidden scene. All logic and reason dictate that he knew of Blackbeard's skill which was made apparent when they did fight.
We see them fight. We see they are clearly peers in terms of strength. Acting like he was overtaken without seeing the captain is hilarious. You really like Barbossa I get it. Logic dictates you cheat to gain an illegal advantage. Logic also dictates you wouldn't do so against an inferior opponent.
How is that hilarious? People working on the Revenge didn't even see the captain until they tried to take the ship. Acting as if a person who can take control of your ship without fighting would fight anyway is ridiculous. Especially considering that's his M.O. even when his crew attacked. He didn't fight at all until he left his ship so we can't assume that changed for no reason at all.
EDIT: But i get it. You just want to pretend stuff happened with zero proof. Have fun with that
I am just thinking through this logically. You aren't. You want to pretend people cheat against his inferiors. We see them fight on screen. Whether they fought or not Barbossa wasn't more skilled in direct comparison. He cheated to win.
So it's logical that Barbossa saw a guy so reclusive that his own men haven't seen him? And that this guy actually fought and risked his life in combat when he could have easily just used their ship against them (which was what was implied)?
This guy is shown to not only avoid fighting by using the magical sword but to also allows his minions to do the work for him while he stays in his quarters.
Barbossa just lost his leg and was trying to kill Blackbeard in revenge. He could not be sure it would come down to an actual duel with Blackbeard's crew. He poisoned it to have a better shot at actually killing him. Defeating him in a duel was not the goal.
Spin it however you want. Cheating implies a lack of confidence in his superiority over him. You can pretend their fight should be thrown away. Who has Barbossa beaten anyways ?