The Tueller Drill is the study of the time it takes a person at rest to cover 21 feet and deliver a fatal injury with a knife. The answer depends on the condition of the attacker.

That is why semiautos must fit into the IDPA “box.” Major manufacturers have taken this into consideration when designing new models like the Glock.
Tests have clocked a fit person accomplishing this task in less than 1.5 seconds. This is important because it starts getting you thinking about what you can do with your 1.5 seconds to counter an attack. If you cannot draw and hit a stationary target at 21 feet in less than 1.5 seconds, you’ll have to have a Plan B. These situations in IDPA also put you under a certain amount of pressure, and learning how to function under pressure is a good thing. Therefore, time is a dynamic aspect of the defensive mindset, and IDPA helps you experience it.

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