In the past debates between a gun vs a knife, distancing played a huge role against a close quarter attack. Twenty-one feet rule, a principle came from the famous “Tueller Drill” that pits two people against another at 21 feet apart. One armed with a pistol but holstered the other armed with a knife. The drill starts when the person armed with a knife starts running towards the other to attack, this cues the other person to draw their pistol to defend himself. With much testing it was confirmed twenty-one feet was the minimal distance for the LEO to react with ample time to survive a close quarter attack.
Man vs Cat
The above video shows situation dictates and sometimes the twenty-one foot rule can’t be applied, let alone against a very quick cat. The background of the video is unknown in terms of, if the man was drawing the cat out so it can be put away due to the survival of a local village. Or, this hunter(s) preying on this prize cat. Fortunately, in this video the man already has his pistol out and ready, and did get a shot off at the cat and struck it. The cat did close the gap and attacked but was wounded. The man survived the close attack with minor scratches.
Source: 4Gifs.com, Imugur, Wikipedia, LiveLeak and Youtube