Will 10,000 hours of practice make you an expert at anything? That's the uplifting message of a slew of recent books, but, sadly, it's not quite true.
For one thing, how long it takes to get good at something depends on what it is that you are trying to learn. You can master tic-tac-toe in an hour, whereas a musical instrument can take decades. In highly competitive professions with rapidly changing technologies, the best practitioners are always learning something new, throughout life; "10 years" is at best an approximation, and sometimes only the beginning.
Just as importantly, the kind of practice matters. What the expert on expertise Anders Ericsson calls "deliberate practice" is essential; if you keep practicing what you already know, instead of pushing your limits, you will quickly reach a plateau. Getting better isn't just a matter of logging hours. It's a matter of developing a focused program of targeting your weaknesses and broadening your skill set.
And, finally, studies that show that practice makes perfect don't show that talent doesn't matter. Everything that we do is mediated by both our genes and the environment, and that is as true in skill-learning as in any other sphere of life. Even in Ericsson's most famous and widely-cited original studies, some musicians with 10 years of experience outplayed some others that had practiced for 20 years. The Beatles were already famous 7 years after John Lennon got his first guitar; Anvil is still struggling 30 years later. There's probably no "music gene", and certainly no gene specifically tailored to a skill like golf that has only existed in recent human memory, but that doesn't mean that Paul McCartney or Tiger Woods weren't genetically blessed. Both were prodigious practicers but genetically lucky, too.