There is only one rule that you take into a knife fight.
You are going to get cut.
How bad how deeply or if at all depends on how you react.
When I taught military security (or words to that effect) we had a drill that we did at the end of the week when everyone was razor sharp and on point. This drill was used to prove a point, closure.
Two students would stand back to back. One student (Student A) faced a steel silhouette target at 20’. The other (Student B) behind him/her facing down range. For fun we would have them put their hands behind their back. On the BEEP Student A was to draw their firearm and hit the target THREE times (Think Mozambique drill) Student B was to take off to the far end of the range as fast as they could.
Instructors were set up on the back side of the range to annotate the spot where the 3rd shot hit steel in comparison to the person running. With VERY few exceptions (usually instructors) did the shooter get 3 on steel before the runner made the 21 YARD line, 21’ is five steps and the common “threshold” of defensibly against a personal attack.
Take from this what you will, I know where I stand but I challenge all of you to see how well you do against a runner with a knife. Oh, do 50 pushups before the BEEP just to get a feel for some stress.