Why do athletes stretch before a game?
to increase their range of motion
to increase their muscular strength for the game
to bring good luck and improve their chance of victory
to increase the number of calories they burn

A) To Increase their Range of Motion.

Explanation:

For Example FootBall, stretching allows them to jump farther, take bigger steps, and run further and faster with using less energy, and stretching also may help with catching a ball with more flexibility. (Stretching helps with Flexibility)