Putting the hours in
Malcolm Gladwell popularised Anders Ericsson’s work on deliberate practice in his book Outliers: The Story of Success. Incidentally, I found Ericsson’s Peak a better read.
Whichever version of the idea you read, I believe nobody could master (not ‘be very good at’, but ‘master’) a subject (or a game like chess) without a significant amount of deliberate practice. What I am less sure about is whether the same amount of practice leads to the same results for everyone. That means that I don’t put much faith in the mythical 10,000 hours (a figure created by Gladwell; since largely debunked) to become a master. It may be a ballpark figure, but it is not THE figure.
In this article in The New Yorker, Maria Konnikova describes the work of Zach Hambrick, who suggests that practice plays a role, but is not nearly the whole story. Genes, work ethic and environment are just as important.
An interesting read, but I for one will be careful not to use a lack of the correct genes, or the correct environment when I was younger, as excuses for not progressing. I will continue to practice deliberately, work deeply and focus on my process goals. I may never master chess, but a very large number of hours of deliberate practice may just help me on the way.
Chess is one of those disciplines where ‘mastery’ can be quantified. It is therefore likely that the number of hours required to achieve mastery could be roughly defined, although it would vary by individual.
Music, on the other hand, is more subjective, and so are most other subjects that can be ‘mastered’ – languages, sports, programming, etc.
In my opinion this makes ‘mastery’ in chess more difficult because it’s
a) competitive (and becoming more so over time)
b) definite (charisma, birthright, self-confidence – while nice to have won’t improve your FIDE score, whereas in many other areas these are professional advantages.