But that isn't talent we're talking about then. The fact that it is hard to define doesn't mean that we should use an incorrect defintion. If we're basing it on achievements, Ferrer is more talented than Gasquet. See the problem?
Also, people rarely consider the importance of the choices made early in a player's career. Is it talent that made Nadal choose such an unconventional forehand technique? It's not as if Nadal has better hand-eye coordination than everyone on tour. He owes a lot of his success to, as it turns out, his choice to develop that forehand technique instead of something more conventional. The reverse probably applies to Murray, since he developed a forehand technique that is pretty restrictive. It is entirely suited to counter-punching, which means he struggles when he has to be aggressive.
So success has a lot to do with the choices made early on.
Nadal used a different forehand technique before Uncle Tony made him change it. Do you think it's too late for Andy to change his?