Goalkeepers should be constantly adjusting their position depending on where the ball is. Good positioning is vital in a game where the pace is quick. In theory, the keeper should place themselves in a direct line between the ball and the centre of the goal.
As well as moving left and right, the keeper must also be ready to move forward. If an attacker is through on goal, the keeper must aim to make themselves as big an object as possible. At the same time, he will be restricting the attackers view on goal. The best thing a keeper can do is to try and narrow down the angle of the shot by forcing the attacker wide.
Doing this however, can be good and bad. If the keeper comes out too far or not far enough, too soon or too late, you will hand the initiative to the attacker, who may dribble, pass or go for a chip. The keeper should advance quickly when they see the ball is outside the attackers playing distance. When the attacker has the ball under close control, the goalkeeper should watch the movement carefully and take a ready position.
Good positonal play can often make difficult saves look easy. Indeed, keepers who are consistantly making spectacular saves may be guilty of poor positional play. Being in the right place at the right time is perhaps one of the most important aspect of the goalkeeper’s art, the probably the most difficult to learn. Good judgement comes with experience.