There's a psychology professor at Florida State named Anders Ericsson who is an expert on "elite performers" [such as Tiger and Roger, at left].
I've come across his name a few times in various articles, including this one from the NY Times and this one from Business Week.
Fast Company had a Q&A with Professor Ericsson that kind of summed up his research, which essentially contends that the best performers "aren't genetically superior. They just do things differently."
Here's a his interview from Fast Company:
Q: Is talent overrated?
A: "The traditional assumption is that people come into a professional domain, have similar experiences, and the only thing that's different is their innate abilities. There's little evidence to support this. With the exception of some sports, no characteristic of the brain or body constrains an individual from reaching an expert level."
Q: What do you have to do to become the best?
A: "Successful people spontaneously do things differently from those individuals who stagnate. They have different practice histories. Elite performers engage in what we call "deliberate practice" -- an effortful activity designed to improve individual target performance. There has to be some way they're innovating in the way they do things."
Q: Can you explain how deliberate practice works?
A: "Here's a typical example: Medical diagnosticians see a patient once or twice, make an assessment in an effort to solve a particularly difficult case, and then they move on. They may never see him or her again.
I recently interviewed a highly successful diagnostician who works very differently. He spends a lot of his own time checking up on his patients, taking extensive notes on what he's thinking at the time of diagnosis, and checking back to see how accurate he is.
This extra step he created gives him a significant advantage compared with his peers. It lets him better understand how and when he's improving. In general, elite performers utilize some technique that typically isn't well known or widely practiced."
Q: So does experience matter?
A: "Just because you've been walking for 55 years doesn't mean you're getting better at it. It's very hard for older engineers, for example, to stay competitive with young engineers trained with new and improved methods.
Those who are successful have to put in a lot of extra time to learn about these new methods. You have to seek out situations where you get feedback. It's a myth that you get better when you just do the things you enjoy."
[Here's an article from Triathlete Magazine that discusses the characteristics of "elite performers.]