Hitting a baseball 420 feet at 15 years old is quite an impressive feat and indicates exceptional power and skill in baseball. While it is not common for the average 15-year-old to achieve such distances, there can be some natural variations in physical abilities and skill levels among individuals.
If your son has been actively playing baseball for some time and has received proper training and coaching, it's possible for him to have developed advanced hitting skills. Genetic factors, physical conditioning, and dedicated practice can also contribute to exceptional performance.
It's essential to encourage and support his talent, but also to ensure that he continues to prioritize safety, sportsmanship, and teamwork while playing sports. If he's showing significant promise in baseball, it might be worth considering seeking guidance from experienced coaches and mentors who can help him further develop his skills and potential.