Eliminating mistakes is not the same as gaining expertise
Deliberate Practice to Acquire Expertise
"Deliberate practice involves two kinds of learning--improving the skills you already have and extending the reach and range of your skills. The enormous concentration required to undertake these twin tasks limits the amount of time you can spend doing them.
The famous violinist Nathan Milstein wrote- “Practice as much as you feel you can accomplish with concentration. Once when I became concerned because others around me practiced all day long, I asked [my mentor] Professor Auer how many hours I should practice, and he said, ‘It really doesn’t matter how long. If you practice with your fingers, no amount is enough. If you practice with your head, two hours is plenty.’”
deliberate practice: what it is and how to do it
Interview with Dr. Anders ericsson a cognitive psychologist who has dedicated his career to the study of performance and expertise. malcolm gladwell's introduction of the 10,000 hour rule in his wildly successful book, outliers, was based on Dr. ericsson's work. unfortunately for gladwell, he incorrectly cited ericsson's work. It is not 10,000 hours, it is more likely 25,000 - 35,000 hours and more importantly, those hours must be comprised of deliberate practice.
While this interview is more specific to emergency medicine, it is important to note the similarities between emergency medicine and a self-defense situation. in both instances, the situation is ambigious and novel with the potential for loss of life and actions taken under time pressure.