All the way up GAME
Force = click starting position - the finger position, is a vector, the club by gravity, the force applied object, other players three factors, watch judge ball movement, so as to apply appropriate size and the direction of the force, players have maximum limit the force applied, each time to exert a force ball maximum limit will reduce, That is, the amount of force the player can put on the ball becomes less and less, and the maximum limit increases when the ball hits effectively (a very short period of time in a row is called an invalid impact).