Why boys good at playing out door games

Not all boys are good at playing out door games. Girls are good at out door games too. In some cultures girls have not been allowed to participate in outdoor sports. They have been prevented from developing athletic abilities. Where they have been treated as equal, they too excel on all levels.

You need to start paying more attention. There are strong and talented athletes of both sexes. It depends on the individual not their gender. Boys may choose rougher sports because of their ages old need to prove their manliness. Girls only need to prove they're good at sports and a great many have done that!