and a few months after he did it john landy broke 4 minutes, and then a whole slew of runners broke it easily. the current world record is 17 seconds below 4 minutes. 4 high schoolers have gone below 4, and college kids do it all the time. bannister's genetics didn't determine breaking 4. i dont feel all have the same potential or ability but i think it's impossible to know how far a person can actualize their potential.