From Hero to Villain in a Single Kick

Save a goal in a penalty shoot-out and you win stardom, miss and you may be turned back at the border on the way home. In a split-second moment, you're either hero or villain.

But with the aid of science, some say, it's possible to take the perfect penalty. New details on the type of research Roberto Baggio and Stuart Pearce would have loved could be available for players lining up from the spot now that the 2006 Cup has reached the knock-out stage.

There are a number of ways sports physicists and psychologists say they can enhance the chances of players on either side of the ball.

What the scientists say

One of them is in training keepers in body language. Goalies who are alert to the kicker's eyes, body posture and angle of his feet in the approach can gain as much as half a second to move in the right direction.

Scientists at John Moores University in Liverpool showed goalkeepers life-sized video footage of penalties being taken, filmed from the viewpoint of a keeper standing in the center of the goal.

The film was stopped four times during the sequence -- 120 milliseconds before the kick; 40 milliseconds before; at the point of impact; and 40 milliseconds after -- and the goalkeepers were asked at each stage to predict where the ball was going to be shot.

Researchers found that the biggest clue was the position of the striker's hips just before the strike.

"If the taker's hips are square-on to the goalkeeper in a right-footed kicker, the penalty goes to the right-hand side of the keeper," the university's Mark Williams said. "If his hips are more 'open,' or angled away from the goalkeeper, the kick tends to go to the left of the keeper."

Research is two-sided

But there are some shots that just can't be saved. A study in biomechanics carried out at the University of Bath in 2004 determined the maximum reach of a goalie's dive, regardless of his size.

It showed that, if the keeper stays on his line in accordance with the rules -- which only the most inexperienced keepers bother with -- 28 percent of the goal is an "unsaveable zone" that guarantees a score, provided the ball is kicked accurately and with reasonable force.

But if you have to choose between placement and force, research shows blasting the ball to be the way to go.

"Hit your penalties as hard as possible," Kassam advised. "Research indicates that a penalty struck at more than 20 meters per second (73 kilometers, 46 miles per hour) stands a greater chance of hitting the back of the net than a slower one, as a goalkeeper has less time to analyze visual clues and react."

According to FIFA statistics, the kicker holds all the cards. In the history of the tournament, 182 penalties have been awarded with 147 converted or 81 percent. Thirty-five have been missed with 22 of those blocked by the keeper.