Soccer goal-line controversy

In last Sunday's (27 June 2010) Soccer World Cup's last 16 match between England and Germany, the match officials failed to see Frank Lampard’s shot go over the line, a fact confirmed by video replay within minute of the event occurring.

This has reignited a debate over changing the sport’s rules. Some favor video replay, some favor an additional referee who would only monitor each goal area, while others would prefer a sensor-system for goals similar to that used in hockey. FIFA, it seemed, continued to resist calls for goal-line technology.

Lampard's shot was interesting from science point of view. Normally when the ball is kicked, hit the underside of the goal bar, then hit the ground behind the goal line, it should bounced to the net behind the goal.  The law of reflection in physics should be sufficient to explain this.  But in this case, the ball bounced back into the playing area, why? Is it because of the back spin on the ball? Is it because of some irregularities on the ground where the ball hit it? Or is it because of the Jabulani ball?  I think FIFA's technical people should study and understand this phenomenon.  Perhaps the answer to this goal-line controversy can be found from this study.

FIFA may continue to resist the call for use of goal-line technology.  Perhaps it is because of the high cost.  I wish to suggest a very simple goal-line technology for FIFA to consider.  It is not very advanced or very high tech.  In fact, it is very much a third world technology only.

In analysing Lampard's shot, my basic question was "How can we prevent the ball from bouncing back into the playing field once it hit the ground behind the goal-line?"  Once this question is asked we can brainstorm and identify many possible answers, including

1.  Put glue in the area behind the goal-line so the ball will stick to it,

2.  Put rubber mat with suction cups behind the goal-line so the ball will not bounce back,

3.  Dig hole behind the goal-line and fill it with water (similar to steeplechase water jump area) so that when the ball hit the water, it will not bounce back,

4.  Make the ground behind the goal-line slope downward, so that even with the ball back-spinning it will not bounce back to the playing area,

5.  Etc, etc

I think answer #4 above is very good potential solution to this goal-line controversy.  This solution may satisfy FIFA as it is not high-tech goal-line technology, the evidence of a goal will be instantaneous and no time is wasted and it can be implemented anywhere in the world very very cheaply.

Of course, it needs to be studied and developed further, including its practicality, safety aspects, etc.  How steep should the incline of the slope be to ensure that the ball cannot bounce back to the playing field not matter the speed of the back spin on the ball? Perhaps the slope should only start R cm behind the goal line (where R is the radius of the soccer ball) - this will ensure that the ball wholly cross the goal-line when it hit the ground.

Think about it......