The 10,000 hours rule is determined to be considerably exaggerated:
Recent research has demonstrated that deliberate practice, while undeniably important, is only one piece of the expertise puzzle—and not necessarily the biggest piece. In the first study to convincingly make this point, the cognitive psychologists Fernand Gobet and Guillermo Campitelli found that chess players differed greatly in the amount of deliberate practice they needed to reach a given skill level in chess. For example, the number of hours of deliberate practice to first reach “master” status (a very high level of skill) ranged from 728 hours to 16,120 hours. This means that one player needed 22 times more deliberate practice than another player to become a master.
A recent meta-analysis by Case Western Reserve University psychologist Brooke Macnamara and her colleagues (including the first author of this article for Slate) came to the same conclusion. We searched through more than 9,000 potentially relevant publications and ultimately identified 88 studies that collected measures of activities interpretable as deliberate practice and reported their relationships to corresponding measures of skill. (Analyzing a set of studies can reveal an average correlation between two variables that is statistically more precise than the result of any individual study.) With very few exceptions, deliberate practice correlated positively with skill. In other words, people who reported practicing a lot tended to perform better than those who reported practicing less. But the correlations were far from perfect: Deliberate practice left more of the variation in skill unexplained than it explained. For example, deliberate practice explained 26 percent of the variation for games such as chess, 21 percent for music, and 18 percent for sports. So, deliberate practice did not explain all, nearly all, or even most of the performance variation in these fields. In concrete terms, what this evidence means is that racking up a lot of deliberate practice is no guarantee that you’ll become an expert. Other factors matter.
To put it bluntly, it’s bullshit. You will NEVER rise to the top of any skill-related activity through nothing more than determination and practice. I have played far more than 10,000 hours of soccer in my life, and while I am an effective club veteran’s team player, I still don’t have one-tenth the soccer ability that some of the club juniors had by the age of 13.
There is no question that one will improve with practice. But one does not achieve superlative mastery through practice alone. Talent matters, and it matters more in certain activities. No amount of practice will make the average individual into a mediocre sprinter; sprinters are born, not made. Nor will 10,000 hours of practice turn a 5’7″ man into an NBA center or a plodding wordsmith into Shakespeare.
Moreover, the entire concept is fundamentally based on a questionable foundation. Recall that the Swede and his colleagues asked various musicians at a single German academy to estimate how much time they’d spent practicing their instruments since the time they began playing it as children. That wasn’t science, that didn’t even rise to the level of credible polling.