Question Number: 28382

Law 1- The Field 4/29/2014

Barry Stewart of Chilliwack, BC Canada asks...

This question is a follow up to question 28352

Me again! I love these discussions¦

Both panelists have talked about the ball touching any part of the penalty spot. I'm wondering if this understanding carries on to other marks on the field.

My understanding for sidelines and goal lines, for example, is that a vertical plane extends upward from the outside of the line. Imagining this plane as a thin sheet of water¦ if any part of the ball would be 'wet,' then the ball is not completely out. Correct?

If this is the same understanding for the penalty spot and the corner arc (among others), then the 'shadow' of the ball is all that needs to be touching the line (with the light source coming from above.)

Your thoughts?

Answer provided by Referee Jason Wright

Hi Barry,

I'm glad to see you're enjoying the site!

You are correct in your description of vertical plane extending above the line. That's why the laws state the ball needs to 'wholly' cross the line to leave the field of play; your description accurately clarifies that. I like your analogy with the sheet of water!

When, for instance, returning the ball into play for a throw in - the moment any part of the ball is 'wet', it's back in play.

Answer provided by Referee Joe McHugh

Hi Barry
Good analogy about the sheet of water. More modern example of this is the recent Goal Line Technology where the technology detects whether the ball was broken the plane of the line fully. If any part of the ball has not fully crossed the plane then a goal has not been scored . The same would apply to touchline and goal line decisions.
The challenge really is detecting it at speed using the human eye.