I'm more of a Fed fan than a fan of Brady and Jordan. But the more impressive thing about Brady and Jordan is how they rose to the top of a much larger talent pool working very hard. Would Fed have accomplished the same thing if there were comparable numbers of youths working as hard to excel in tennis as there are working to excel in football and basketball?
This dynamic is one reason I've tried to steer my own children toward disciplines with lower levels of competition - where a certain amount of laziness can be depended on among most of the competition in the field. Take shooting for example, because of the ammunition and range expenses, a teen who starts early can be competitive (and I'm talking top 5) in a given state (and possibly even nationally) with about an hour of shooting practice a week for several years. Instead of requiring thousands of hours of practice, success in shooting only takes thousands of rounds of practice ammunition - hundreds of hours of practice. Likewise, success in mountain biking, fencing, mini-golf and Ultimate frisbee requires much less practice time and skill than the big sports: football, basketball, baseball, hockey, etc.
The fruit in tennis is a bit higher to reach than shooting, mountain biking, fencing, etc., but it is also considerably lower than the most popular sports. After 3 years of practicing an average of 6 hours per week, my son is ranked in the top 25% of players in his age group. We estimate that it would take more than twice the practice time to put him in the top 10% (the scholarship zone), but we choose to focus on academics instead. But another year at his current level of practice might put him in the top 15%, still outside the athletic scholarship zone, but much higher than he would possibly be with similar effort in the more popular sports.
But compare all sports to academic pursuits like science and engineering, and the sports lose. In addition to making good use of the standard class time for academic subjects, I can turn most above average students into top 1% performers in science and engineering with about 200 hours a year extra. Why? Because the other 99% is not working very hard, and the fruit hangs pretty low.