Of 106 kids, 98 ultimately made it to the professional level, 10 rose to the top 100 players in the world, and a few climbed all the way to the top 10.
[...]
When the researchers eventually fit their data to the actual rankings of the players later on, the children’s tennis-specific skill scores predicted 60 to 70 percent of the variance in their eventual adult tennis ranking.
[...]
The tests of general athleticism — for example, a thirty-meter sprint and start-and-stop agility drills — influenced which children would acquire the tennis-specific skills most rapidly.
[...]
“We called Steffi Graf the perfect tennis talent,” Schneider says. “She outperformed the others in tennis-specific skills and basic motor skills, and we also predicted from her lung capacity that she could have ended up as the European champion in the 1500-meters.”
Graf was at the top of every single test, from measures of her competitive desire to her ability to sustain concentration to her running speed. Years later, when Graf was the best tennis player in the world, she would train for endurance alongside Germany’s Olympic track runners.
[...]
The future pros not only tend to practice more, but they take responsibility for practicing better.
[...]
“What we see in the shuttle sprints,” Elferink-Gemser says, “is that the ones signing a professional contract later are the ones that are on average 0.2 seconds faster when they are younger, at the age of twelve, thirteen, fourteen, fifteen, and sixteen. They are always on a group average about 0.2 seconds faster than the ones who end up on the amateur level. That really gives some indication that it is important to be fast. You need a minimum speed. If you’re really slow, then you cannot catch up, and speed is really hard for them to train.”
[...]
“We’ve tested over ten thousand boys,” he says, “and I’ve never seen a boy who was slow become fast.”
Nature vs. nurture: Answered.
In Graf’s case, she had top-notch Nature and Nurture — and one of her great natural advantages was that she was willing and able to train very hard, with great focus, for hours and hours.
Hmmm! Some might argue that Ms. Graf’s willingness & ability to train hard was also part of Nature.
Of course, the Nurture part was that she was encouraged & enabled to pursue excellence in tennis — versus being sent into a mine with the other children to dig cobalt for those environmentally admired windmills and electric vehicles.