Those genetic requirements come into play at elite levels, but you need to start young, when those differences are less obvious.

You need to look at what sports an eight-year-old is playing in the backyard, what sports his Dad is excited about on the TV.

An agile, fast, coordinated kid who's coachable and wants to train hard but is going to grow up to be 5' 8" is not going to make the NFL or the NBA, but if they've got the athleticism to play in the World Cup... well, in the US that kid will be the point guard on the local high school basketball team and also play safety and wide receiver on the football team.

In India, they'd be a cricket star.