Professional athletes are genetic freaks first and foremost - look at the dropoff from college football players to professional players. It's not talent that determines who makes it, it's genetic ability. The absolute worst NFL team in history would decimate the best college team in history just because of the difference in size, speed, and strength of the people on the professional team.
The NFL uses the standing vertical jump as a test of athletic ability because it's one of the only tests that can't be trained. No matter how much stronger or more explosive you get, your standing vertical jump pretty much stays the same. And guess what, people who make it in the NFL are the ones with the highest standing vertical jump.
1) https://en.wikipedia.org/wiki/List_of_shortest_players_in_Na...