Ender is a 6 year old boy. He has no relevant experience in practically anything.. Still, he is Earth's 1st and only choice in its last and final survival battle against a coming Alien attack that may extinguish Earth, and life as we know them.
Ender was chosen for what he was - a brilliant strategist, a constant self-learner and above all, a survivor, a winner.
If i meet Ender, i will invest in him... no matter his experience.
I urge you to read Ender's Game by Orson Scott Card.