An interesting topic to me is whether it is better for young athletes to play one sport only or to play different sports in different seasons. I had not thought about this for awhile but was reminded of the topic by Michael Arace's article here in the Columbus Dispatch. I also found this article on a site for coaches. I think one of the interesting points in Arace's article is that spending so much time doing the same activity likely increases the risk for injury as the same muscle groups are used again and again.
I admire my nephew's attitude. He is a Wyatt Teller, 4 star high school defensive end recruit from Bealton, Virginia who has committed to Virginia Tech for 2013. He is the youngest of 5 children for my brother and sister-in-law. Although he may have dreams about playing in the NFL, I have not heard him speak of that possibility. He talks about going into law enforcement. Although many athletes dream of playing professionally, the realty is that the vast majority of athletes do not get a scholarship to play in college and so many fewer ever get paid to play professionally.
The first time I coached youth soccer, my team of 6 year olds scored one goal the entire season but went 0-10. At the end of the season, they seemed to have learned a lot about soccer, had a number of hours of good exercise, and (probably most importantly) had a ton of fun. For the vast majority of youth athletes, those are the important things: the exercise, learning the sport, playing with team members, and having fun.
I am all for pursuing one sport if that is what your child enjoys, they are not having excessive injuries with it, and it otherwise works for the family. But many children benefit from participating in multiple sports throughout the year.