The best expert performances, whether of athletes, musicians, chess players, surgeons, or writers, are creative and adaptive and executed with compelling grace. That requires deliberate practice, an idea based on the research of Anders Ericsson and associates. They found that expert performances in a wide range of arenas required intense exercises focused on finding and correcting minute mistakes. In practicing deliberately, students do not just repeat, but correct errors through experiments and problem-solving. The most effective teachers and coaches work to induce and amplify mistakes by disturbing repetition.