My thoughts about choosing position is easy: A player will never be able to rise to his/her full potential playing a position they do not really like, or they actually would like to play something else. Keep that in mind. Do what you like best!
What really can make the difference is that player that is keen on playing and practicing. ... willing to push the limits he/she might have. So, go after every ball, never give up. Do not accept limits. That will bring you far! Good luck! :)