Defender brought down in the box - denied opportunity to intercept attacker.

[Murri O]

Attacker (A1) is running into the box on the right hand side of the 18 heading towards the corner of the 6 yard box preparing to shoot. A defender is running to intercept the attacking player (A1). Another attacker (A2) is trailing the defender. The trailing attacker (A2) holds his line. The defender, in front of the attacker, holds his own line and crosses in front of A2 (as they were running different lines) and gets ankle tapped and tripped. A1 scores as the defender cannot make an intercept. I am 95% confident, as was my AR, that the defender would have been able to make the intercept. (He may not have stopped the shot but was denied the chance to make the intercept.)

2 questions: What is the correct call for the above scenario and secondly what would you call if the defender was brought down in the exact same scenario but 4 or 5 metres away. IE effectively backplay.

Bear in mind all of this happened in a instant and you won't be surprised to hear there was a fair bit of pandemonium following my call.

 

[ChasObserverRefDeveloper]

Attacker (A1) is running into the box on the right hand side of the 18 heading towards the corner of the 6 yard box preparing to shoot. A defender is running to intercept the attacking player (A1). Another attacker (A2) is trailing the defender. The trailing attacker (A2) holds his line. The defender, in front of the attacker, holds his own line and crosses in front of A2 (as they were running different lines) and gets ankle tapped and tripped. A1 scores as the defender cannot make an intercept. I am 95% confident, as was my AR, that the defender would have been able to make the intercept. (He may not have stopped the shot but was denied the chance to make the intercept.)

2 questions: What is the correct call for the above scenario and secondly what would you call if the defender was brought down in the exact same scenario but 4 or 5 metres away. IE effectively backplay.

Bear in mind all of this happened in a instant and you won't be surprised to hear there was a fair bit of pandemonium following my call.

This is a classic "You have to see it" situation. Based on your description . . .
If the attacker tripped the defender it's a direct free kick to the defending team.
Whether or not the defender would have been able to intercept attacker A1 is immaterial.
If the offence occurred 4-5 metres away, same outcome - dfk to the defence.

 

[OIREF!]

As already stated you would have to be there but as you describe it I'd say DFK to the defending team.

 

[JamesL]

If a player is tripped in a careless, reckless or excessive force manner, it doesn't really matter what they might have been able to achieve. A direct free kick offence has been committed and so the restart would be a DFK to the player that was tripped team.

As its a yhtbt (you had to be there) I can also see this the other way from your description as impeding the progress of an opponent. You say that he moved into the path of the opponent with the ball not being in playing distance, in which case you could apply advantage.

You have to determine, who has committed what offence against who and go from there.
What you can't do is not penalise an offence on the basis the player could not affect play.