wasd to move, arrows to rotate
angle the side of your sword towards the top of the center of the game (way above the net), and jump when the ball is near your sword
a bump, but angled lowly. takes a lot of skill to do right. keep account that the ball's x momentum carries through a hit and doesn't have 100% bounce
Jump when ball is low on x velocity and rotate sword towards other side, very precise but very rewarding.