The Ericsson model: intentional, focused repetition
Deliberate practice is not just practice. Any musician plays; not all play deliberately. The Ericsson model requires a specific goal (improve wrist speed, not 'get better'), work that sits just beyond current ability (the discomfort zone), and immediate feedback on each attempt. A pianist practicing scales deliberately watches for timing errors, hears them instantly, and adjusts the next scale.
Passive repetition does not drive improvement. A driver with 20 years of experience may have the same skill level as one with 2 years if they both drive the same route on autopilot every day. Deliberate practice, by contrast, produces measurable improvement over months and years.
Feedback and the error-correction loop
Feedback is the engine. Without it, you repeat the same mistakes. A tennis player hitting balls alone against a wall gets no feedback about spin or placement accuracy. With a coach who points out the angle of the racket at contact, the player adjusts. The next swing is different, and the result is better.
The feedback must arrive fast (during practice, not days later), it must be specific (not 'good effort', but 'your elbow bent too early'), and the learner must act on it immediately. Delayed, vague, or ignored feedback wastes the time in the practice loop.