Forty-five years ago, William Chase and Herbert Simon drew groundbreaking conclusions while studying expertise. They studied the masters and grandmasters of chess, examined the thousands of hours of practice that they put in, and came to the conclusion that no matter how talented a person may be, rigorous training that involved a massive amount of time is necessary for mastering a complex task. John Hayes, a psychologist, studied 76 classical composers and realized that almost all the composers were able to create their greatest work only after having been composing for a minimum of ten years. The 10,000-Hour Rule Malcolm Gladwell