Let us start with data from identical twins:
That is from the forthcoming Seth Stephens-Davidowitz Don't Trust Your Gut: Using Data to Get What You Really Want in Life. From such reasoning you can divine the relative import of genetic factors for success in various sports. Here are the derived calculations, with the number indicating "Percent of Same-Sex Siblings Who Are Identical Twins" (when both make the Olympics, or achieve some other status):
Track and field: 22.4%
Wrestlers: 13.8%
Rowers: 12.4%
NBA players: 11.5%
Boxers: 8.8%
Gymnasts: 8.1%
Swimmers: 6.5%
Fencers: 4.5%
Shooters: 3.4%
NFL players: 3.2%
MLB players: 1.9%
Alpine skiers: 1.7%
Divers, equestrian riders, and weightlifters: All zero percent.
