talent
1. A marked innate ability, as for artistic accomplishment.
2. Natural endowment or ability of a superior quality.
In the first sense, a talented player would be one with an innate ability, with born-like aptitudes, as such, I feel talent is rather unobservable.
However, looking at the second definition, you could interpret having talent as the ability to do things better than most. Superiorly, better than say 95% of people. Running faster, hitting more shots accuratedly, serving more aces. It is tricky in any case, since it has to be "natural" or "innate". Was Conchita Martinez born with the latent ability to hit perfect moonballs, or did she come up with them due to her lack of speed?
Most people understand talent as "ease". How easy does it look? Popular belief seems to be that if it looks easy, then it's probably a talent. If it has required 4,000 hours of hard work at it, is it really a talent? It looked like Hingis was a talented shot-maker. It looked so easy. It looks as if S. Williams is a talented athlete, you see her running faster, jumping higher, and it looks so easy.
But you know what? Serena Williams and Martina Hingis have probably dedicated 4,000 hours of hard work at it.