system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] Could a non-force sensitive individual become a competent Lightsaber duelist?

Before everything else, I know about Grievous, but he had the advantage of being cybernetically enhanced. I'm talking about a normal individual just training really hard. 

Now, let's say that there is a non-force sensitive individual who is nonetheless extremely good at martial arts. Through intense training and physical conditioning, they achieved their peak and are able to perform crazy physical feats of martial arts, parkour, etc. Now, this person just happened to also train extensively in the Jedi lightsaber forms , studying the finesse of each form for years and trying to find (or create) a style best suited for themselves.   


How would this person, who by normal standards is absolutely exceptional, compare to an average Jedi or Sith?
gpt
They could become competent enough to maybe survive a fight against a force user, but the thing you're never going to get around is combat precognition. 

A Jedi or Sith is going to know what this opponent's next move is before they know it themselves.  That's going to make it near impossible to win a fight.