Again, I am presenting the “five legs” of a gun fight”, so to speak, as recounted to me by those with impressive tactical resumes. Those five legs are: 1) unplanned situations unfold in the blink of an eye; 2) they happen at very close range; 3) they involve very few rounds; 4) they happen in less than optimal lighting (not darkness); 5) all participants are likely to be moving.
For your entertainment, I will present a real life 19th century shoot-out that happened in the infamous Long Branch Saloon, Dodge City, Kansas. This story emphasizes point number 2 (close, really close) of the above five legs. You kind of wonder how it would have all turned out, if each had an ATS on his six-shooter.