I predict that DJT is going to run away with this one. If for no other reason than I believe the rules are going to result in, at least, the PERCEPTION of a lot stronger performance.
Reasoning: As I understand it, the rules include that there is no audience and that mics can be muted so we don't have the train wreck of interruptions and over-talking that have been the hallmark of other DJT "debates." Personally, I'd love to hear an actual debate where the candidates are able to punch-counterpunch like an actual debate, but those times are long gone.
Conventional wisdom would say that this will benefit Biden because he won't have to fight the interruptions and can get out his canned responses.
I think the conventional wisdom is flat wrong. To be sure, we the viewers won't be hearing Trump's interruptions and interjections. But I have absolutely ZERO confidence that he won't be making them. Therefore, I expect him to be a monster distraction to Biden and expect him to trip Biden up significantly, but on TV, it'll look like Biden is just doddering because we won't be able to hear what Trump is saying. The dream scenario for Team Trump might be that during a Biden answer that Biden pops off asking him to shut up or something. It'll have "old man yells at clouds" vibes because we won't be able to hear what came before.
Anyway, just some thoughts.