Why assistant referees so often get it wrong

Why assistant referees so often get it wrong: Scientists

Spain will not be the only team to agree, but Jose Camacho's men will lead the way in endorsing the findings of Dutch scientists here who say assistant referees frequently make mistakes about the offside rule.

Psychologists from Amsterdam's Free University found that assistant referees make a mistake in one out of every five decisions.

The men with the flag are usually in the wrong position to judge whether a player is offside and are thus vulnerable to an optical illusion, the researchers found.

The news, bolstered by scientists' recommendations that contentious decisions in a key matches be determined by video analysis, may come as no surprise to Spain, who were eliminated from the World Cup after they were denied two 'goals' in their clash against South Korea who went on to win 2-1 through a golden goal in sudden death overtime.

Even FIFA president Sepp Blatter admitted the accuracy of assistant referees was "a major problem," and said he was especially worried about offside decisions.

"This is a point where we have to put our importance for the future," Blatter said last Saturday even before Spain felt the pain of elimination.

The offside rule says that a player must have two defenders between them and the goal when the ball is passed to them.

The goalkeeper is usually one of these two, which leaves the assistant referees to decide whether the attacker is beyond the first defender.

But the researchers discovered that assistant referees are usually behind the position of the defender, rather than level with them, when they have to make the judgement call.

By a trick of perspective, an attacking player who goes outside the defender, in a position close to the referee, looks as if he is onside.

Conversely, an attacker who goes inside the defender in the same position and from the same viewpoint, looks offside.

The reverse is the case if the situation occurs on the other side of the field from the assistant referees.

In this case the player who goes outside the defender is more likely to look offside to the man with the flag.

In other words, an attacker could be ruled offside less often if he runs inside or outside the defender, depending on the position of the assistant referees.

The researchers published their study in Nature, the prestigious peer-reviewed British science journal, in March 2000.

Their study was based on exhaustive work. They assembled two elite youth football teams and generated potential offside positions which were judged by professional assistant referees. A video camera, perched on a nearby apartment block, kept record.

In 200 offside situations, the assistant referees made 40 errors, the researchers found. Their conclusions were backed by analysis of offside decisions made in the 1998 World Cup.

"Given the high stakes in modern football, this incidence of (inevitable) errors suggests that alternative ways of judging offside should be developed, such as off-line analysis of video images taken from an adequate observation point," the psychologists warned.

Italy have been the most critical about the performance of the assistant referees in the 2002 World Cup, claiming they have had at least three goals disallowed by errors over offside.