A successful attack works because the opponent is busy. Busy blocking or evading something that is not there, busy striking something that is not there, busy being frozen by something they think is happening, (or is actually happening) or just busy with the white noise in their heads ...
They have to be busy doing something other than dealing with what you are actually doing.
Don't be where they think you are, don't strike where they think you're striking and commit when they are busy dealing with your ghost.
Here's a great clip of Bernard Hopkins talking tactics with Rashad Evans before a fight. What he says about rhythm, timing, cutting angles, range and set ups holds just as true for dueling. Thanks again to Steve Morris for sharing: