The ability to curve a soccer ball is a skill that both players and coaches know is difficult and requires a lot of practice to perfect. When defenders are aligned tightly in a wall to block a shot, it may seem to some spectators that it is an easy target to score in the undefended portion of the goal. However to get the ball in the net the striker must place the ball accurately. To make the ball go down in time it cannot go too high over the wall of defenders. The sticker has to maintain tight control of the speed and initial elevation of the shot. In addition he has to accurately gauge the width available for proper placement of the ball. Many have referenced Roberto Carlos, a Brazilian national player’s use of the Magnus Effect as for his free kicks. Fans have looked on in amazement as Roberto strikes the right side of the ball with the outside of his left foot and the ball curves left around a wall of opposing players and into the goal. When he hits the ball with the outside of his left foot on the right side of the ball’s center of gravity it causes the ball to rotate counterclockwise and curve to the left. When the ball rotates counter clockwise in the air the air flow on the left side of the ball is faster causing the pressure to decrease on the left side of the ball. The airflow on the right side of the ball is slower because it is moving in the opposite direction of the rotation of the ball causing the pressure to increase on the right side of the ball. The increase of pressure on the right side of the ball and the decrease in pressure on the left side of the ball causes the ball to curve left.
