Also, it's an Olympic event in between the long jump and the triple jump...............in all seriousness, this is a great question and very helpful answers as I was reading about the U.S.Open format this year and they have a detailed explanation of this courtesy rule and it was completely news to me. I make fun of the guys who need more than one lane - but then again, I can't see out of my left eye so half of my battle is won!