WHEN DOES “INVOLVEMENT” BEGIN?

Question:
I have been seeing AR’s call offside, with the center accepting it, in what I think is a too early of a call. I have read the August 24, 2005 position paper on offside and am still unclear, and I hope you can clarify this for me. Here is the situation: Player in an offside position near midfield and there is a long and possibly angled through ball. The OSP takes off after it with defenders in pursuit and the flag gets raised immediately. I agree with this if the ball is going toward the keeper and there is concern about a collision. I also agree with it if you know the ball is going to stay in the field of play and the OSP is obviously the player who is going to get to the ball first, or at least be able to immediately pressure a defender who might beat him to the ball. But what I’m talking about are the times when it is very possible the through ball might end up across the end line or go across touch. I know we are suppose to keep the flag down if there is the possibility of an on-side player reaching the ball first, but it also seems we should wait for actual involvement if we are not certain if the ball was going to stay in bounds. It has been explained to me (by experienced refs) that offside should be called because it would be more advantageous to the defending team to have a free kick near midfield than a goal kick or a throw-in. To me that seems to be faulty logic. If the OSP did give chase, without an offside call, and the ball goes across the end line the restart would be a goal kick. Which would be the same restart had the OSP failed to give chase. If the movement of the OSP had no effect on the ability of the defense to reach the ball, then the movement of the OSP had no effect on end result of the ball crossing the end line, i.e. there was no involvement. To make a premature offside call in this type of situation seems to unfairly penalize the attacking team by giving the defense a free kick near mid-field as oppose to a goal kick, or possible a throw-in. Can you let me know how to call these types of plays?

USSF answer (January 12, 2012):

You yourself had the answer when you said “The OSP takes off after it with defenders in pursuit ….” That is the exact and precise moment the AR’s flag should go up and play be stopped for an offside violation. Everything in your scenario after this quote is pure sophistry and dithering as to the intent of everything that has been written about offside since the International Board issued its three definitions of what constitutes an offside violation (interfering with play, interfering with an opponent, and gaining an advantage). 

The question would have been a lot tougher if every defender had simply stood there while the OSP attacker had begun his run downfield, but they didn’t. They pursued. That pursuit alone constitutes “interfering with an opponent” because, according to the International Board, the OSP attacker has acted to distract or deceive one or more opposing players.