This post introduces one of the most difficult decisions a referee has to make. But before we get into the details, I strongly suggest you test yourself using the below video.
It will show you 25 very brief clips that ask you to decide if the player is offside or not. Then at around 4:20 you will be given the answers for each of the 25 clips. How did you do?
What makes it so difficult to correctly decide if the player is indeed offside is the limitation of the human eye and brain. It’s called the Flash-Lag Effect, which makes a moving object appear to be ahead of its actual position.
Click here for a great webpage if you want to dig deeper. I’m quoting:
Top referees are aware of the Flash Lag Effect and practice hard to factor it into their thought process when considering whether a player is in an offside position. They also know that the faster the players are moving, the more tolerance they have to factor in to their decision making.
This is why close offsides are the most difficult calls in the game. The AR has to override what his own eyes and brain are telling him and, if they make a correct call, when it appears to every person in the stadium including himself that he is incorrect, then that call is of genius proportions.
Here is probably one of the most ‘genius’ decisions in World Cup history. Look very closely at the final still image showing the heal of the defender keeping Chicharito onside.
However, as Offside Explained says, “this decision could have gone either way – at this speed had the pass come 0,02 seconds later we would see a clear offside in the still-image. There is no way for a (human) referee to know if it’s offside or not.
Also, according to the laws we have to evaluate head, body and feet. When players are running fast it is very hard to recognize the position of the feet vs body.
This is why we have to accept marginal mistakes when the player is offside and there is fast movement. But the players and the fans do not accept nor understand this, but there is no other way for the referees.”
The only solution to this is technology – either video replays (as is currently being tested successfully at the top level in select leagues) or somehow tagging and then sensing in real-time the position of every part of each player’s body and the ball, which is much more complicated than video replays.
In the above World Cup example a video replay would have been an obvious decision. The game was halted anyway because a (suspected) goal was scored. The referee would run to the sideline to watch a replay in super slow motion and then determine if the restart is a kick-off for blue (if Chicharito was indeed onside and scored a valid goal) or a free kick for blue (if Chicharito was offside after all).
Unfortunately, at the youth level coaches, players, and spectators will have to accept the errors that the Flash-Lag Effect introduces into the game.