Interfering with an opponent - Explanation

This article has come into existence upon consultation with an international assistant referee who was able to clarify that in accordance with the instructions UEFA officials are receiving.

A perpetual issue in current refereeing controversies, and even UEFA Champions League Semifinals, is the improvement of Law 11, the offside rule, called "interfering with an opponent".

What is it at all?

FIFA Laws of the Game clearly define the case of "interfering with an opponent". A situation will become an offside offence, if an attacking player prevents an opposing defending player from being able to play (the ball) by...:

• ...obstructing the opponent's (normally the goalkeeper's) line of vision,
• ...making a movement ...
• ...or a gesture, which deceive or derange the opponent.

This means that a defender can be punished for being in a - so far - passive offside position, which becomes active by one of the exposed criteria.

The following paragraphs will solely focus on the first criterion, as these cases are probably the most significant and furthermore the most frequent ones in today's football.

Position is all what counts. The Laws do not ascribe importance to the question of whether the position, which can be penalized as offside offence, is the result of complete arbitrariness. Therefore, it does not matter whether a player was in this position unintentionally or not, as long as he had not been edged by an opponent off into this position in a chargeable way. 

However, from which point or distance does an attacker influence the goalkeeper's line of vision? The Laws do not clarify that in a direct way.

Rafael Ilyasov (UZB) indicating the first offside goal at 2010 FIFA WC

Instead, the Laws lay heavy emphasis on the "opinion of the referee". It is also important that not merely the assistant referee is responsible for deciding that. These incidents recently happened in scored goals as well. So what happens if you - as an assistant referee - are not sure whether one or perhaps more players blocked the goalkeeper's view? The best solutions are, if you are sure. Then you can either decide 100% no offside or 100% offside - 100% goal or 100% no goal. As professional assistant referees confirm, this is more likely a rarity. After e.g. corner kicks, when a mob of 15 players moves within the box, the situation might be undiscerning, there is the possibility that you wrongly grasp the depth. 

Assistant Referees are in general instructed to apply the "wait-and-see-technique" (the term actually explains itself). If they are nonetheless not sure at all, if there are still doubts, they have to stand still (no movement!), which is a clear signal to the main referee whom the assistant referee is supposed to consult, as he has mostly a deeper insight in the situation.  

The signal of standing still is supposed to be applied in two circumstances:

• Either if the assistant referee is not sure, which player (perhaps in a header-duel) touched the ball last...
• ...or if - as described - there are doubts whether an attacker in an offside position potentially blocked the goalkeeper's LOS.

An exemplary conversation via wire could be like that:

After the signal of standing still:

The Referee should ask him: "Hey mate, what's wrong?"

The Assistant Referee should say: "A red player was standing in front of the goalkeeper in offside position. Do you think it was a chargeable interference?" 

REF should say: "The ball passed him with a small distance (e.g. 10 cm), so this was a clear interference of the goalkeeper's line of sight ("LOS"). 

AR : "Ok mate, good job"

Result: No Goal, Offside!

The responsibility for the correct decision has been then shifted to the main referee. Mostly, however, assistant referees ignore this technique in order to not cause the referee's embarrassment. If an assistant referee takes the blame, he will admittedly get only a 7,9 or something like that in the UEFA mark system, but he will have to fear less consequences as if the referee had got this mark. Paradoxical, but this seems to be reality. As for UEFA matches, Collina has the perfect solution. Now we see more. Apart from the fact that it does not work either, the idea of the additional assistant referee is actually quite expedient in these situations, he has mostly a perfect view for it. Unfortunately, Mark Clattenburg did not utilize this opportunity in last week's UEFA Champions League Semifinal in München.

Luiz Gustavo (the red player who is the closest to Casillas) clearly interfered latter's view and potentially even distracted him.

Unfortunately, blogger was not able to insert another video directly into the post. Follow this link to see the assistant referee 2 Stephen Child obviously applying the standing-still-technique (0:57 f.) as display of his doubts, however, Howard Webb did not react on that. It is even worse. He directly signaled the goal, which means that there was obviously no time for a conversation.

And another, final example. In South America's Copa Libertadores, the Paraguayan assistant referee César Franco did not even see a reason for wait-and-see...it should have been ruled offside, too, at least a consultation with his chief Carlos Amarilla appears as necessary.

However, you may also find someone who does not agree with that, because the attacker in the last video cannot be penalized for being there.
A lot of controversial decisions like that and many completely diametrically different opinions on them reinforce that this rule has to be simplified.