It's never exactly the same tbh.

Sometimes, I can see the person I'm sparring clearly, without lag which is usually when my internet is better than usual and I can do more, But sometimes I only see people warping around and I know if I spar I'll get absolutely destroyed I rarely win when I can't even see what is happening because basically everything in my spar relies heavily on predicting.

As for if I know where to hit, it's somewhat like above, Usually different by a bit every time. I can't exactly tell where my character is seen or where to hit. It's usually the same I'm about a character length away give or take or above a character and a half if you have people standing side by side. sometimes more or a bit less. Usually in spar I'll do a "trial and error". If I'm doing C style and they are as well. I'll suddenly hit the top of where they would go in a C style formation. And if they
A. Get hit, I can better guess how far I should predict by seeing how far I walked away
B. If they suddenly jerk away, I know they must've seen my character and reacted to dodge it therefor I know I must shorten the area I should predict ahead of in order to hit them so they can't react and avoid.